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Earthquake Hazard Assessment Practice and Velocity Models and Reference Events in the Mediterranean Region

 

Santa Susanna, Spain

 20-25 May 2001

 

With a Short Course on:

Understanding and Applying Probabilistic

Seismic Hazard Analysis

 

United Nations Educational, Scientific and Cultural Organization

Paris, France

Contact:  Dr. Soren T. Malling

Telephone:  33 1 45 68 41 22

s.malling@unesco.org

 

Executive Summary

 

The Mediterranean region, because of its geological structure, seismicity, topography and climate, has been frequently subjected to natural disasters resulting in great losses of life and property.  Field studies and investigations of disasters indicate that large portions of the land surface, population, infrastructure, and industry of the region have been subjected to earthquakes in the past or will be subjected to earthquakes in the future.

 

In recent years, there were several major, damaging earthquakes in the Mediterranean region.  Therefore, in the interest of reducing earthquake risk in the Mediterranean region, UNESCO and the Instituto de Ciencias de la Tierra 'Jaume Almera' – CSIC convened a workshop in Santa Susanna, Spain, 20-25 May 2001, on Earthquake Hazard Assessment Practice and Velocity Models and Reference Events in the Mediterranean Region.  Contributed papers on seismology and engineering were invited.  More than 50 participants from the following countries attended the workshop: Algeria, Belgium, Cyprus, Denmark, Ecuador, Egypt, France, Greece, Israel, Italy, Iran, Jordan, Lebanon, Libya, Morocco, Netherlands, Saudi Arabia, Solvenia, Syria, the Palestinian Authority, Spain, Turkey, United States, and Yemen.

 

This workshop continued efforts addressed in similar RELEMR workshops in Amman, Jordan, 4-7 May 1998, in Istanbul, Turkey, 14‑17 October 1998, Nicosia, Cyprus, 3-7 May 1999, and in Istanbul, Turkey, 29 May – 2 June 2000; the goals of those workshops were to foster data exchange among countries in the region and to conduct joint activities and experiments that would improve the quality of seismic data in the EMR.  In Amman, working groups were formed on 1) seismic calibration and 2) the development of a RELEMR seismic hazard map.  The 1998 workshop in Istanbul was organized along these themes.  The Cyprus-1999 workshop added sessions on the role of auxiliary station operators and their responsibilities and the interaction with their earthquake-reporting activities.  The Istanbul-2000 workshop was dedicated to seismic calibration using the Dead Sea explosions and selected natural events.

 

In addition to the workshop, Dr. Robert T. Sewell (USA) presented a one-day training course on: Understanding and Applying Probabilistic Seismic Hazard Analysis and panel discussions were held on Earthquake Hazard Assessment in the Mediterranean Region and on Velocity Models and Reference Events in the Mediterranean Region.

 

Maria-Jose Jimenez presented the Keynote Address on The Unified Seismic Hazard Map of Europe and the Mediterranean.

 

Thirty contributed papers were presented that discussed various aspects of earthquake hazard assessment and velocity models and reference events in the Mediterranean region.

 

Participants were taken on a one-day field trip to the ‘La Garrotxa’ volcanic field, the Volcano Museum of Olot, and the area affected by the XVth century damaging earthquake series.

 


Introduction

 

The Mediterranean region, because of its geological structure, seismicity, topography and climate, has been frequently subjected to natural disasters resulting in great losses of life and property.  Field studies and investigations of disasters indicate that large portions of the land surface, population, infrastructure, and industry of the region have been subjected to earthquakes in the past or will be subjected to earthquakes in the future.

 

In the EMR, these earthquakes are associated with the northward movement of the Arabian plate.  The 1,000 km long western boundary of the Arabian plate is a complex plate boundary, extending from zones of sea‑floor spreading in the Red Sea to zones of plate convergence in Turkey, and lies along the line of the Gulf of Aqaba, the Dead Sea rift, and the Ghab depression.  The sense of motion along the Dead Sea transform fault system is left lateral, with the eastern side moving northward relative to the western side.  Total displacement is estimated at about 107 km since Oligocene time, with an annual rate of about 0.5 cm. over the last 7 to 10 million years.

 

On 22 November 1995, a Mw 7.2 earthquake occurred in the central Gulf of Aqaba region causing damage in nearby communities in Jordan, Egypt, Israel, and Saudi Arabia and was felt for more than 700 km.  An aftershock sequence lasted for more than one year with numerous shocks exceeding Ms 5.0.  The size of the main shock and some of the aftershocks demonstrates the threat that earthquakes pose to the EMR.  These events occurred during RELEMR’s (Reduction of Earthquake Losses in the Eastern Mediterranean Region) second Joint Seismic Observing Period (JSOP‑II) and therefore we have the ability to accurately locate the earthquake sequence by integrating data from all the national networks in the region.  This permits greatly improved accuracy in epicenter and magnitude determinations.  In October 1997, a workshop was hosted by the Cyprus Geological Survey Department to locate the main shock and approximately ten aftershocks.

 

In the western Mediterranean region, which includes portions of Greece, Italy, Spain and northern Africa, seismicity is widely distributed and seismic hazards are high.  Modern interpretations of this seismicity suggest the existence of seven micro-plates, with seismic activity concentrated at the micro-plate boundaries, which coincide with the Alps, Appenines, and Hellenic arc.  Among the most notable recent (1996) seismic events was the M=6.8 earthquake in the historic city of Assisi in the Italian Appenines which destroyed numerous cultural artifacts, including important frescoes.

 

Since 1993, the U.S. Geological Survey (USGS) and UNESCO have been cooperating with EMR earth science organizations under the RELEMR program.   Countries from the western Mediterranean region have also participated.  The European-Mediterranean Seismological Center (EMSC) has coordinated the exchange of data among EMR countries and, since 1996, LLNL has also been cooperating in the program.

 

 

The Spain-2001 Workshop

 

Background

 

In recent years, there were several major, damaging earthquakes in the Mediterranean region.  Therefore, in the interest of reducing earthquake risk in the Mediterranean region, UNESCO and the Instituto de Ciencias de la Tierra 'Jaume Almera' – CSIC convened a workshop in Santa Susanna, Spain, 20-25 May 2001, on Earthquake Hazard Assessment Practice and Velocity Models and Reference Events in the Mediterranean Region.  Contributed papers on seismology and engineering were invited.  More than 50 participants from the following countries attended the workshop: Algeria, Belgium, Cyprus, Denmark, Ecuador, Egypt, France, Greece, Israel, Italy, Iran, Jordan, Lebanon, Libya, Morocco, Netherlands, Saudi Arabia, Solvenia, Syria, the Palestinian Authority, Spain, Turkey, United States, and Yemen.  The list of participants is given in Annex A.

 

In addition to the workshop, Dr. Robert T. Sewell (USA) presented a one-day training course on: Understanding and Applying Probabilistic Seismic Hazard Analysis and panel discussions were held on Earthquake Hazard Assessment in the Mediterranean Region and on Velocity Models and Reference Events in the Mediterranean Region.

 

This workshop continued efforts addressed in similar RELEMR workshops in Amman, Jordan, 4-7 May 1998, in Istanbul, Turkey, 14‑17 October 1998, Nicosia, Cyprus, 3-7 May 1999, and in Istanbul, Turkey, 29 May – 2 June 2000 and 25-27 October 2000.  The goals of RELEMR workshops are to foster data exchange among countries in the region, to conduct joint activities and experiments that would improve the quality of seismic data, to improve hazard assessments in the Mediterranean region, to improve the dissemination of earthquake engineering data, and ultimately to improve the seismic provisions of building codes in the region.  In Amman, working groups were formed on 1) seismic calibration and 2) the development of a RELEMR seismic hazard map.  The 1998 workshop in Istanbul was organized along these themes.  The Cyprus-1999 workshop added sessions on the role of auxiliary station operators and their responsibilities and the interaction with their earthquake-reporting activities.  The first Istanbul-2000 workshop was dedicated to seismic calibration using the Dead Sea explosions and selected natural events, the second Istanbul-2000 workshop was dedicated to large earthquakes in the region. The program and abstracts for this workshop are presented in Annexes B and C, respectively.

 

 

Short Course

 

UNDERSTANDING AND APPLYING PROBABILISTIC SEISMIC HAZARD ANALYSIS (PSHA)—Presented by Robert T. Sewell

 

During the workshop held in Istanbul in 2000, S. T. Algermissen presented a two-day seminar on Probabilistic Earthquake Hazard and Risk Assessment.  This seminar presented an overall view of earthquake hazard and risk assessment so that the participants would have an understanding of the many scientific and engineering elements required for these kinds of studies.  Emphasis was on the types of data required, preparation of the data for hazard and risk assessment, the types of assessment possible and the development of suitable hazard and risk models.

 

The training course presented at this workshop by R. T. Sewell was designed to allow the participants to acquire an enhanced understanding of how to use PSHA software (FRISKSP).  Using a laptop computer and projector, Sewell showed participants how to: hand calculate probabilities of exceedance of ground motions for simple cases, hand calculate a uniform hazard spectrum given hazard curves for spectral accelerations at multiple vibration periods, and incorporate near-source and site-response effects in obtaining PSHA results.  He also provided participants with an enhanced understanding of how site-specific seismic design criteria are developed and applied.

 

Workshop Proceedings

 

Sunday 20 May 2001

 

Opening Session

 

M. Garcia-Fernandez, Instituto de Ciencias de la Tierra 'Jaume Almera' – CSIC, welcomed participants to Spain and to the workshop on behalf of the organizers and sponsors.

 

S. Malling, UNESCO, indicated that previous RELEMR meetings dealt with the eastern Mediterranean with some participation of western Mediterranean countries and that this meeting is a little different as it formally includes the entire Mediterranean region.  RELEMR started in 1992 with the help and cooperation of scientists from the region and we are now trying to produce a regional ground-shaking map(s) at scale(s) appropriate for engineers and planners and move to probabilistic hazard assessments.

 

M. Foose, USGS, also emphasized the need for regional ground-shaking map(s) and the exchange of data and ideas.  He also expressed concern for the lack of progress between meetings and how to keep the effort going between meetings.

 

F. Riviere, EMSC, indicated that the EMSC gathers data for the region on behalf of the EU and is the data agency for RELEMR.

 

Invited Dinner Speaker/Workshop Dinner

 

Maria-Jose Jimenez: Unified Seismic Hazard Model for the European-Mediterranean Region

 

·        Unified seismic hazard map of Europe and Mediterranean programs: SESAME/GSHAP/ESC WG-SHA

·        GSHAP produced a heterogeneous set of regional hazard maps from the integration of independent hazard results

·        SESAME also tried to produce a unified model of Mediterranean region

§         unified model for sources and attenuation

§         source model: 351 sources + attenuation laws + probabilistic seismic hazard assessment = seismic hazard maps

§         now have a new unified seismogenic source model

§         now have a homogeneous map of Mediterranean region and integration with Europe

§         SESAME/ESC WG-SHA – work wrapping up

§         need continuation and cooperation

·        A comprehensive model of hazard assessment for the whole European-Mediterranean region has been developed

·        Generation of hazard maps, expressing ground motion in different parameters

§         peak ground acceleration (0.3s and 1.0s spectral acceleration)

§         different soil condition (rock, stiff soil)

§         different probability levels (1%, 10% and 65% of exceedance in 50 years)

·        A suite of final hazard maps for the whole European-Mediterranean region are being published in 2001 as a closing activity of the ESC/SC-F Working Group on Seismic Hazard Assessment.

 

 

Monday 21 May 2001

 

Keith McLaughlin: Use of Reference Events to Validate 3D Models in the Mediterranean Region for Location Calibration

 

·        Calibrating the Group 2 stations in the Mediterranean/North Africa region

·        Goal is to improve locations with sparse global network

·        Developing reference events, models, correction surfaces

·        Reference events are used to validate 3-D models in the Mediterranean region to improve location calibration

·        Improved locations are based on the sparse IMS network: reduce location bias and uncertainties

·        Reference events are needed for 3-D models, travel time curves, modeling errors, and validation

·        IASPEI (Bonder and Engdahl) are also collecting reference events

·        3-D ray tracing through model(s), correction surfaces referenced to IASPEI91 model

·        Reference events:

§         GT0: known explosion

§         GT2: mine explosion

§         GT5: local network, aftershock

§         Reference events validated by cluster analysis

·        Collected 837 GT0-5 events (200 more on the way) and 13,012 regional phases as of 5 April 2001

§         Validation is proceeding

§         CMR is looking for additional reference events in the Middle East/North Africa

·        CU Boulder model, Harvard Model (smoother)

·        SAIC Model of Crust (Vp & Vs)

·        Need phase arrivals for 94 IMS and surrogate stations

·        Silesia Poland Mine, Gulf of Aqaba cluster, other clusters available

·        Feedback is welcome; presently CMR is preparing preliminary surfaces

·        Everything will be posted on web site

 

Torild Van Eck: ORFEUS and MEREDIAN

 

·        Observatories and Research Facilities for European Seismology

·        Mediterranean-European Rapid Earthquake Data Information and Archiving Network

·        Funded by the European Community

·        Data available within a few hours for Mag. >5.5 globally and >5.0 within Europe

·        MEREDIAN goal is the real-time waveform data exchange, open rapid access

·        Real-time data gathering via internet, Antelope, AutoDRM, SeisComp (GFZ-Potsdam)

·        QuakeExplorer (Anthony Lomax, Univ. Nice): Java based package to access data and do basic analysis

·        Real time data requires lots of bandwidth, presently only event data available

·        Website: http://orfeus.knmi.nl/meridian

·        AutoDRM help is available once the database is set up  – contact Florence Riviere or Torild van Eck for help in installing software at receiving institution

·        Depends on cooperation, access to internet; does not depend on IMS/IDC

·        ORFEUS - earthquake waveform data

·        ORFEUS also reports to FDSN (IRIS, Pacific21, Geoscope, Geofon)

·        ORFEUS access is free through the web

 

Avi Shapira: Travel-time modelling in the Middle East

 

·        Based on the Dead Sea Calibration Experiment

·        Verified regional travel time model

·        Locations based on grid search of first arriving P and S waves with manual weighting

·        Assess the minimum picking error, assess the location accuracy, test several models

·        Dead Sea shots observed out to teleseismic distances

§         DSE recorded in Cyprus and Greece but none in Turkey (7-11 degrees)

§         DSE known as GT within 50 meters and time within 20 milliseconds

·        Location and origin time determined from close in observations

·        Observations fit IASPEI91 model

·        Scatter in picks of first arrivals is 0.2 – 0.3 seconds (1-sigma)

§         This determines a bound on the accuracy of any model or correction scheme

·        One-dimensional model(s) fit the data within the uncertainties

·        Large differences in crustal structure between Mediterranean and continental regions

§         EMR does not have a homogeneous crustal structure, however, there is a homogeneous TT model

·        Searched for differences in Eastern and Western regions, relative to the Dead Sea Transform

§         GII found 4-layer model (e and w of fault) rms is about .247 sec. from picks and scatter, so this is probably the best in the region

§         currently used model by GII fits the TT measurements of the DSE very well

·        A number of models produce essentially the same locations, due to the good distribution of stations. Challenge to IMS and global locations is the paucity of stations.

·        Model is probably accurate out to 700-800 km from Dead Sea

·        3 model - unified, west model, east model - what is the effect of location/relocation of DSE?

·        All models gave same difference in times based on all (different) models

·        What is secret of model independence?  Get good distribution of stations

 

A. Rodgers and A. Al-Amri: Seismic velocity models and ground truth development in the Arabian Peninsula: A U.S.-Saudi Arabian cooperative project

 

·        Results from analysis of Saudi, Kuwaiti, Jordanian and Israeli data

·        Used KSU, KACST combined with UCSD network in Saudi Arabia

·        Seismicity/crustal structure affect propagation

·        Showed interesting event in southern Kuwait (in REB) that might originally been considered induced

§         BB waveform analysis argued that depth was 10km

·        Future work may involve: 1) further BB deployments, 2) help with hazard analysis, 3) site response studies, 4) tectonics

·        Arabian shield: High Q crust, low Q (slower) mantle

·        Sediments thicken toward the Gulf—up to 10 km

·        RAYN could not see P-waves from DSE

·        Pn velocity 7.75 km/s (slow!) to NW Saudi Arabia along Dead Sea Rift.

·        BB waveform modeling

§         Looked at Love and Rayleigh wave group velocities across Arabian shield

§         Crustal thickness in shield and platform is 36 Km

§         Red Sea events can only be modeled after using anisotropy

·        Determine structure using waveform modeling

§         Red Sea anisotropy has significant S wave anisotropy

§         Gulf of Aqaba GT events from JSOP (Sweeney)

§         Method works also in Kuwait for waveform modeling

§         Used mining event clustering to find mining events for GT

§         Saudi attenuation so low that Lg can be seen as far as 600 km from mining shots

·        Zagros events recorded by ~10 KACST BB stations plus Kuwait BB

§         Will model waveform

·        Gulf Aqaba GT events

§         Multiple stations within 30 Km

§         Will relocate KACST data based on manual picks

§         Wants to merge Egyptian data

 

K. Nakanishi: Data sharing in the EMR

 

·        Joint Seismic Observing Period (JSOP) was very successful, but participation has flagged. Why?

§         Proposed the assembly discuss: 1) distribution of parametric data, 2) velocity models, 3) regional magnitudes, reference events

§         Possible next steps 1) common standards, 2) waveform exchange, 3) autodrm, 4) training for UNIX/LINUX, 5) virtual regional data center

·        Some observatories are not contributing to the JSOP

§         Need to develop data sharing and possibly a joint bulletin for consistency

§         Need common software/platform/methodology

§         Broadband seismic data is becoming more common

§         Virtual regional seismic data center? Could serve as a data exchange point.

 

Hadi Gashut: Earthquake activity in Libya and the importance of the Libyan National Seismograph Network

 

·        Libyan Center for Remote Sensing and Space Science (LCRSSS)

§         Established in 1989

§         Has responsibility for seismic monitoring

·        Libya affected by regional tectonics

·        Most earthquakes are in the Hun Graben (Al-Qadahia) & Al Jabal Al Akhdar regions

·        There is some activity in the south and off-shore in the Gulf of Sirt

·        Historical earthquakes

§         As large as M 7.1 (Hun Graben)

§         Date to the year 262

·        The LNSN is currently being deployed and consists of both broadband and short-period stations

§         5 stations (3BB, 2SP) in phase I

§         5 later (2BB, 3SP) in phase II

§         Will start with 3 stations (NE, NW and S parts of country)

·        Collaboration exists with ETH (Zurich) MEDSEA experiment (2 BB stations, 2 year project)

 

Walter Hays: World Congress on Disaster Reduction

 

·        World Congress on Disaster Reduction

§         Pre-meeting August 2001

Ø      Reston, Virginia, USA

Ø      19-22 August 2001

§         Meeting in 2002

·        Congress themes

§         Living with disasters

§         Building to withstand

§         Learning from disasters

·        Congress goals

§         Sustainability

§         Disaster technical assistance

§         Education

§         Create regional centers of excellence for  sustainable development

·        Strategic goals

§         Solicit “Global Blueprints for Change” for presentation at the First World Congress

Organize regional forums for change

 

D. Slejko: Hazard Assessment Practice in Italy

 

·        GNDT seismic hazard project  - just completed in Italy

·        National project for seismic hazard

§         source data

§         seismotectonics

§         attenuation       

§         probabilistic methods

§         deterministic method

·        Data catalog with 40000 events

§         only about 4000 events studied

·        Delineate Italy and the Adriatic in a zonation map into 80 zones

·        Attenuation relations

§         Abraseys

§         Sabetta-Pugliese

·        Peak ground acceleration common but not necessary best assessment of hazard - better to use spectral attenuation

·        Site effects need to be taken into account

·        General hazard projects have ended and now regional projects have started

·        Differences between the 1996 and 1999 maps

§         Updated earthquake catalog

§         New completeness approach

§         Weighted seismicity rates over entire catalog

§         No maximum magnitude for the seismic zones

§         Hard boundaries

§         No background zones

§         2 averaged attenuation relations

§         New attenuation relation for the volcanic seismic zone 73

§         Updated differentiated intensity attenuation relations

·        Slejko doesn’t like hard boundries

·        Slejko doesn’t know which map is better

·        Soil types

§         Very soft

§         Soft

§         Rigid

§         Rocky

·        Computed PGA with 475 year return period

·        General Hazard project ended—regional projects are now being started

 

Avi Shapira: Hazard Assessment Practice in the Middle East and Application to Building Codes

 

·        More than 95% of the populations of Israel, Jordan, Lebanon, and the Palestinian Authority are susceptible to intensity VIII

·        27 July 1927 earthquake in Jericho (M 6.2) is the first earthquake with magnitude information

·        1995 M7.1 Gulf of Aqaba earthquake was the wake-up call

·        Flow chart - seismogenic zones, b value and return period, attenuation and site effects

·        Seismogenic zones made by geologists from seismicity information

§         High segmentation of Dead Sea transform means there will not be a M 8.5 on the DST

§         Not much known on Mediterranean seismicity - no faults recognized

·        Many different attenuation functions (at least 10)

·        Question about magnitudes - unify?

·        PGA not a good measure of hazards

§         New building codes will not include PGA

§         Spectral amplitude at 1 and .3 sec

§         Site  classification same as FEMA

·        Need to start site specific stochastic simulations

§         Start with Brune model of S waves (omega squared)

·        Planning (codes) site specific unified hazard acceleration response spectrum risk:  site specific acceleration response spectrum

·        Question - is there a resonant frequency for a building?

§         Each building has many different resonant frequencies

·        Next generation building code Application

§         Spectral amplitudes @ 1.0 and 0.3 sec

§         Site effects

§         PGA without frequency associated with it is meaningless

 

Y. Alpay-Biro: Current developments for seismic hazard assessment for Istanbul and Marmara region

 

·        Detailed fault analysis and history for the last 300 years

§         complicated with possible gaps or periods of quiescence

§         history of damage in Istanbul

§         geology of area (soil types—NEHRP soil classification)

§         inventory of buildings

§         GIS data

§         vulnerability curves

·        Integrated fault map for region around Marmara

§         Data sources

Ø      Infrastructure layouts

Ø      Digital maps

Ø      1:1000 scale maps

Ø      building census

Ø      specific studies

§         Analysis of response to recent major earthquakes

§         Segmented the North Anatolian Fault

Ø      Seismicity shows gaps

Ø      Suggestion of seismic gap between 1912 and 1999 events along the northern fault

Ø      Fault maps of Marara Sea from various sources

Ø      Considered models of fault segmentation

Ø      Trend exists of seismicity through northern Sea of Marmara

·        Istanbul rapid response and early warning project - instrumentation along south crescent of Istanbul (European and Asiatic side)

·        Conclusions

§         Results to be used for assessment of risk and motivation for additional resources and mitigation

§         Very high risk in old town Istanbul!

 

Polat Gülkan:    Source modelling and seismological properties of the recent Turkey Earthquakes

 

·        Recent seismic zonation in Turkey

§         Catalog: 23BC – current

§         Standard procedures

§         Big uncertainty remained in attenuation relationships

·        Review of Izmit & Duzce events

§         Over turned parked vehicles

§         Near-field ground velocities from strong motion

§         ~20,000 killed

§         ~40,000 buildings lost

§         High velocity fling was well documented at a few sites (normal & transverse)

§         Spectra exceeded “California” design criteria but not greatly so

§         Drift demands were excessive however (over 2% several times) in the near-field

·        Seismic zonation map for Turkey

§         Tool for the structural engineer

§         Include 100 years of instrumented seismicity

§         17 seismogenic zones + background zones

§         Parameters estimated for each zone: b-value, Mmax

§         Attenuation relations only recently obtained for Turkey (this is the largest source of uncertainty)

§         Near field strong motion observations of 17 August 1999 and 12 November 1999 earthquakes not enough, given the recurrence periods of large earthquakes

§         Near field (D<10 km) observations are more complicated and accelerations are extremely high – exceeding the Universal Building Code (UBC)

 

Maria Yeroyanni: The Mediterranean Disaster Information Network (MEDIN)

 

·        Programmatic presentation of European Commission funding opportunities

§         38 million EU / year

§         85 projects total

§         30 projects in seismic risk

§         Call for proposals from EC covering seismic hazard mitigation and engineering

§         Also funding remote sensing

·        Goals

§         Exchange of data

§         Improvement of buildings

§         Technologies to monitor EQ

§         Risk reduction/mitigation

·        Going toward larger projects but will entertain small projects

·        EU-MEDIN – Workshop to draft declaration paper

§         Sharing of disaster related information, data & expertise

§         Promote existing and ongoing efforts

§         Define research activities, explore relationship w/ International Disaster Information Network (GDIN)

·        EU contribution to MEDIN

§         Meeting in Brussels 15-17 Nov 2000

§         Foster coordination of research

§         Declaration paper

§         EU representative added to GDIN steering committee

·        Declaration

§         Promote sharing of research results

§         Build on existing work

§         EU-MEDIN steering group

§         Define research activities

§         Explore relationship with GDIN

·        Sttering group

§         Review MEDIN objectives/deliverables

§         Redress EU component of MEDIN

§         Discuss possibility of newsletter

 

I. Cecic: The European Seismological Commission Field Investigation Team (FITESC)

 

·        Survey of damage from several recent earthquakes (photos: Croatia, Central Appinine, NW Slovenia, Turkey)

·        Macroseismic Survey Team for rapid deployment after major earthquakes to collect non-instrumental data

·        Intensity/effects data will help to assess the risk and vulnerability to earthquake damage

·        Need to deploy quickly, before recovery begins (bulldozers destroy the evidence)

·        ESC team(s) could train local teams

·        Data to be shared and posted on the web

·        Cost ~15000 euro/trip for 10 people for 10 days

·        Estimate ~ 1 mission/year on average

·        www.gsrg.nmh.ac.uk/~phoh/fitesc_disc.htm

 

 

Tuesday 22 May 2001

 

Djillali Benouar: A review of the earthquake data bank in western Mediterranean countries (Algeria, Morocco, Tunisia)

 

·        Seismic hazard assessment (deterministic and probabilistic) for North African countries: Morocco to Egypt

·        Need complete and homogeneous earthquake catalog

§         Algeria started in 1980 with the El Asnam earthquake

§         El Asnam earthquake made the government aware of the earthquake risk

§         EQ M=5.5 still kills people—4.5 causing damage

Ø      Excess damage due to poor buildings—modern buildings are better

§         Use instrumented seismicity ~100 years

§         Use historical information

·        Algerian code as of 1988

·        Reconstruct macroseismic field from written reports

·        Reduce the risk by reducing uncertainties

§         Need reliable database to start

§         Problem - change in definitions over history – example: Magnitude mb to Ml; same for intensity

§         Take historic catalogs, look at macroseismic and/or instrumental information

·        Combine everything about country to reconstruct the intensity assessment

·        Algeria now has homogeneous catalog complete with all input data; input in probabilistic method

 

Mehdi Zare: Recent Developments in Iranian Seismic Hazard Studies

           

·        Population density highest in the north and northwest, northern Zagros, sparse population in eastern part

·        Tehran built upon two or more significant faults

§         North Tehran Fault borders Tehran-foothills of Alborz, another fault postulated for the southern edge of Tehran

·        Kerman region along western border of the Lut Desert has had great earthquakes

·        Very complex fault-fault interactions

·        Determine seismic source zones, active faults in urban areas, attenuation laws for strong motions, zoning map

§         Determine seismic source zones from satellite photos and field visits

·        1500 strong motion stations in Iran, including ~1000 accelerographs

·        H/V spectral ratio to classify the site response

·        Greater attenuation in Zagros Mountains compared to Alborz and Central Iran

·        468 three-component stations (sites) have attenuation laws

·        Attenuation Law similar to Joyner-Boore

·        There are very few near-field observations

·        Stress-drop 20-50 bars, implying intra-plate stresses (?)

·        Future work

§         Develop Coulomb stress change maps for fault zones

§         Determine active fault zone in urban areas

§         Develop attenuation laws using recent acceleration data in Iran

§         Generate spectral acceleration maps for Iran (for different periods)

 

Mehdi Zare: Urban Development and Construction Along North Tabriz Fault Zone in NW Iran: A Field Visit Report (May 2001)

 

·        Tabriz is a historical city—several thousands of years of history

§         16 major earthquakes—12 demolished the city—last during French revolution

§         Construction on hills gives both landslide and earthquake risk

§         Much of the construction is government sponsored

·        Right-lateral strike-slip fault (north Tabriz Fault) is primary with left-lateral strike-slip as a secondary fault

·        Construction is approaching the fault

§         10 years ago, only construction was overnight construction (poor people—migrants)

§         Today: 2 million people—200k in region near fault

§         Presented photographs of recent construction near the fault

 

Florence Riviere and Gilles Mazet-Roux: Contribution of the EMSC-CSEM to Earthquake Hazard Assessment Practice in the European-Mediterranean region

 

·        Contributions to Joint Seismic Observing Program (JSOP) 1997-2001

§         IIEES in Iran and KISR in Kuwait started sending data 2001

Ø      Well distributed events throughout the country

Ø      No phase picks from other countries for these events

§         Need to re-establish data exchange

§         Involve new participants

§         Use JSOP to make merged bulletin

§         Consistency of magnitudes

·        JSOP-3 started April 1997

§         Open ended

§         Data exchange in JSOP or GSE format

§         3 to 6 contributing institutes

§         Data available on EMSC web site (phase picks, no waveforms):  http://www.emsc-csem.org

§         Mostly magnitude 2-4

§         To submit JSOP data (bulletins): jsop@emsc-csem.org

·        Create a European-Mediterranean bulletin by merging all available bulletins

§         Preliminary in 1 week

§         Final in 1 month

§         EPSI project funded by EC

§         EMSC can relocate events by merging bulletins

§         Need events outside of contributing countries so that they can be relocated by merging catalogs

·        EMSC alerts for M > 5

§         Automatic mesages from 12 national and local networks and forms

§         Some arrivals and some origins

§         Aim is to send out alert within 1 hour

§         Real time data processing

Ø      Magnitude threshold of 5.0 in European-Mediterranean region

Ø      Analyst runs relocation with available data

Ø      Backup by IGN (Spain) and ING (Italy)

§         40 alerts in 2000

 

Gideon Leonard: Model inaccuracy and bias in hypocenter estimation

 

·        Simulations of location performance

§         IASPEI91 travel times with maximum errors of 2.5%

§         Used IMS stations

§         Constructed different scenarios

§         Three event regions: Sea of Galilee, Dead Sea, Gulf of Aqaba

Ø      1000 events with no model errors

Ø      1000 events, modeling error of 2.5%

Ø      IDC compensates for model errors

·        Bias in hypocenter estimation

§         Travel time and model errors separated

§         Model assumed isotropic

·        Conclusions

§         Negative bias by IDC if IASPEI91 is correct

§         IASPEI91 error is 2.5%

§         Next step - need calibrations

 

Tariq Al-Khalifah: Saudi National Seismic Network

           

·        KASCT network: Saudi National Seismic Network (SNSN)

§         Starting to produce a bulletin

§         Telecommunications has been a problem

§         KSU network started in 1985

§         Royal decree in 1991 for KACST to study earthquakes – but no funding

§         1995 Gulf of Aqaba earthquake led to funding KACST network

§         Kinemetrics deployed system

§         37 stations on leased lines

Ø      BB 0.001-100 Hz

Ø      Concentrated along Red Sea

§         King Abdulaziz University runs 7 station subnetwork

§         All waveform data are archived on DLT tapes

§         A large number of teleseismic events now recorded

§         Converting communications to VSAT

§         Perhaps real time internet connections

§         KSU and KACST networks may be connected to produce joint locations

§         Both systems run ANTELOPE – working on EARTHWORM in parallel

·        Provided CD-ROM containing the Saudi broadband data for the Dead Sea Experiment (Data are included on the CD-ROM included with this report.)

·        Small network run in Medina area

§         Operated by the Saudi Geological Survey

§         Primarily to monitor volcanics

 

Djillali Benouar: Hazard Mapping in Algeria   

 

·        Hazard mapping in the Maghreb countries

§         Used earthquake catalog described earlier

§         Used different attenuation laws to estimate the uncertainty in probabilistic seismic hazard calculations

§         Probability of exceedance for 10/50 years as a function of PGA for Algiers

§         Period dependent spectral amplitude

·        Possibly a seismic gap on Morroco-Algeria border

·        No earthquakes within the interior south of the coast

 

Mohammed Al-Haddad: Seismic Microzonation in Saudi Arabia

 

·        Phase I: First study was of the western coast (Al-Wajah, Yanbu, Jeddah, Jizan)

·        Phase II: Gulf of Aqaba region (City of Haql and Ad-Durra Customs facility)

§         Seismic design criteria

Ø      Proposed using UBC 94

Ø      Some people want to use UBC 97

Ø      Aramco wants UBC2000

§         Soil (amplification) can lead to increase in ground motion

§         Microzonation used to account for local site effects

§         Field tests: bore holes to 30-50 m

§         Shear wave velocities used to define the UBC soil type

§         Could not contour the average shear wave velocity

·        Measurement of Rayleigh wave dispersion

§         Collect samples for laboratory work

§         Depth to bedrock, water table

§         Field work is done at a number of sites within each city

·        City of Haql and Ad-Durra Customs facility

§         50 sites for shear wave velocities

§         Cross-hole shear velocities for 15 sites

§         Vertical electrical sounding

Ø      Depth to bedrock

Ø      Water level

·        Seismic zonation of western Saudi Arabia

§         Refined seismotectonic map

§         Refined seismic source modeling

§         Sensitivity analysis

§         New seismic hazard analysis (NEHRP-97)

 

Jalal Al-Dabbeek and Abdel-Hakeem Jawhari: Palestinian Common Buildings and Variation in Seismic Building Codes

           

·        Seismic education for the public

§         Need to work with citizens and decision makers

§         Radio and television to raise awareness of seismic hazards

Ø      What do we need to do before, during, and after an earthquake

Ø      Al Dabbeek was on 70 TV shows

Ø      Need to change mentality of the people

§         Elective courses in seismic hazard/risk mitigation for all students

·        Building codes: guidelines and formulas for minimum legal requirements for design and construction in an area.

·        Main objective: protect life, health and property

·        MERC project on building codes

§         NRA, GII are partners

·        Many codes considered: Base shear values for four different building styles (10 story, zone 2) solicited from many engineers are quite variable

§         Regional

§         International

·        Factors affecting the seismic base sheer force

§         Seismicity zone

§         Soil effect

§         Occupancy

§         Building

§         Structural system

§         Configuration

 

Ramy El-Khoury: Examples of earthquake resisting system in Lebanon

 

·        Lebanon is a highly vulnerable county

§         Historically recorded earthquakes back to 1st millennium

§         Example: 16 March 1956 Chhime-Chouf earthquake

Ø      Ms 5.4

Ø      136 killed

Ø      6000 houses collapsed

Ø      17000 houses damaged

§         Many felt earthquakes in Lebanon although most are small

·        Building design, modeling and retrofit

§         Examples of earthquake resisting systems in Lebanon

Ø      Reviewed retrofitting tank structure

Ø      Reviewed earthquake properties/construction techniques of new UN building

Ø      Reviewed school: part on rock, part on clay

v     Fault in between

v     Detailed construction

 

Polat Gülkan: Near-field ground motion effects and their correlation with structural damage

 

·        Disaster management research center

§         Polat Gulkan –  Director

§         Established 1997 at METU in Ankara

§         Fields of interest

Ø      Science

Ø      Engineering

Ø      Law

Ø      Culture

Ø      Politics

Ø      Economic consequences

Ø      Mandatory disaster insurance

Ø      Land use management

Ø      Community participation

Ø      Remote sensing and GIS

Ø      MEDIN

·        Strong motion instruments in Turkey

§         120 instruments installed (not enough)

§         Most along Anatolian Faults

§         Most located in government buildings for ease of maintenance and communications

Ø      Building interaction may be important

§         No borehole data

§         Little or no site composition data

·        Fit acceleration spectra to Joyner and Boore model

§         47 records

§         Limited Turkish data set diverges from JB by factors of 1.5 or more

§         All records in buildings – no free field

§         Generally, attenuation relationships are lower than typical values

·        Histogram of S-wave velocity

§         20 150 m/s

§         12 300 m/s

§           9 700 m/s

§           2 900 m/s

           

Jeannette Fernandez: The Global Earthquake Safety Initiative (GESI)          

 

·        Described methodologies for estimating earthquake deaths based on city-specific studies with an evaluation of landslide potential, fire fighting potential, medical preparedness, …

·        Depends on feedback on quality of methodology

§         Principles

Ø      Meaningful

Ø      Easy to understand

Ø      Reasonably priced

Ø      Motivational

§         Monitor improvements cities are doing to improve seismic risk

·        Determine an earthquake fatality potential

§         Buildings

§         Landslides

§         Search and rescue

§         Fire

§         Medical care

·        Steps in making the evaluation

1.      Represent shaking on firm ground; average PGA with 10% exceedance in 50 years

2.      Represent shaking on soft soil; % of city area with soft soil

3.      Define building inventory (9 categories; rate quality: design, construction, materials; select vulnerability curve)

4.      Assign buildings to damage states for each building type and % of buildings in each damage state

5.      Determine % population in each damage state

¨      Assign each building type to light/heavy category for lethality

¨      Determine % of each building type in each height category

¨      Assume building occupancy

¨      Not all at home—reduce by 25%

¨      Assume % occupants with life threatening injuries =% killed

6.       

7.      Represent deaths, injuries by landslide

¨      % city susceptible to landslides (steep slopes)

8.      Represent lives saved by trained SAR teams

9.      Represent deaths, injuries from fires

10.   

11.  Represent effects of medical care

12.  Combine results

13.  Repeat analysis for schools

·        San Salvador is at risk from landslides and Quito is at risk from earthquakes (biggest problem is collapse of structures)

 

Gideon Leonard and D. Steinberg: Seismic Hazard Assessment: Simultaneous effect of earthquakes at close and distant sites

 

·        Motivated by planning for emergency response

·        Six M>6 in last 1000 years, one of these was a M 7 in Israel/S. Lebanon

·        Simultaneous effect of close/distant sites

§         Estimate PGA as a function of epicentral distances

§         Based on J and B 1993

§         Bridges the gap between probabilistic and deterministic earthquake hazard assessments

§         Assume distribution of towns near fault and estimate recurrence intervals

 

 

Wednesday 23 May 2001

 

UNDERSTANDING AND APPLYING PROBABILISTIC SEISMIC HAZARD ANALYSIS (PSHA)—A short course presented by Robert T. Sewell

 

Expected learning outcome

 

·        Be able to hand calculate probabilities of exceedance of ground motions for simple cases

·        Be able to hand calculate a uniform hazard spectrum given hazard curves for spectral accelerations at multiple vibration periods

·        Be able to incorporate near-source and site-response effects in obtaining PSHA results

·        Acquire enhanced understanding of how to use PSHA software (FRISKSP) to obtain PSHS results

·        Acquire enhanced understanding of how site-specific seismic design criteria are developed and applied

·        Acquire a broader knowledge of PSHA issues and applications

 

Course format

 

·        Over 60 key topics

¨      Background concepts (13)

¨      Basic PSHA concepts (18)

¨      Intermediate PSHA concepts (16)

¨      Advanced PSHA concepts (11)

¨      Concluding summary (4)

·        Later key topics build upon earlier ones

 

Handouts

·        166-page workbook

·        CD-ROM containing spreadsheets and all workbook information and data (in the pocket on the back cover of this report)

 

 

 

Thursday 24 May 2001

 

FIELD TRIP to Les Volca de Garrotxa

 

Participants visited ‘La Garrotxa’ volcanic field, the Volcano Museum of Olot, and the area affected by the XVth century damaging earthquake series.

 

The Garrotxa Volcanic Zone, near the old town of Olot, contains the finest volcanic landscape in Iberia. Set just south of the Pyrenees, it includes a high plateau, thirty Strombolian volcanic cones, diverse explosion craters, numerous lava flows, basalt cliffs and verdant river valleys. The last eruption probably occurred about 11,500 years ago. Altitudes vary between 238 m and 1,026 m. Well preserved medieval villages affected by the damaging 1427-1428 earthquake series are found in this region and were visited.

 

 

Friday 25 May 2001

 

Rami Hofstetter and Josef Leonov: New developments in seismic source zoning in Israel and adjacent regions

 

·        Zones defined by GII for Israel and adjacent regions from geologic/tectonic data

§         Most events are in 3 narrow rectangles along the Gulf of Aqaba and Dead Sea Rift

§         NW-SE rectangular zone in Northern Israel

·        Current ISR network

§         Completeness in Israel for ML > 2.1

§         1980’s to present

§         Calculated b value for israel and adjacent regions = 0.97

§         ~20 seismic zones

·        Homogenous magnitude scale for zonation

§         > 5                   1900-1955

§         >4                    1955-1971                   WWSSN

§         >3.5                 1971-1981

§         >2.5                 1982-1984

§         >1.8                 1984-present

·        No magnitudes >5.5

·        Used Wiechert magnitude-frequency relation

·        Lots of activity along dead sea

·        Activity in Gulf of Aqaba is misleading because of 1993-1995 swarms

·        Site effects

§         Failure of borehole section transfer function and micro-tremor analysis to explain PGA anomalies at EIL led to modified Joyner-Boore (1981/2) attenuation relationship

·        Attenuation law for Israel and the adjacent regions

§         Use to revise hazard map and revision of code

§         Data from 16 earthquakes that triggered the strong motion network

§         New data and current attenuation relation are in disagreement and need reanalysis

§         Need to remove site effect from record with deconvolution

§         To get frequency response function, get all available geological information

Ø      Borehole logs

Ø      Reflection and refraction data

Ø      Geophysical prospective data

Ø      Free field ambient noise

Ø      Long-term data acquisition

·        Data analysis and empirical function determination

§         Nakamura method

§         Reference station technique

§         Receiver functions

·        Even with processing, attenuation laws indicate that ground acceleration is too low

·        Data scarcity does not allow making new attenuation laws

·        Alternative is to look at other laws developed recently

§         Considered 11 published attenuation laws from literature

§         Chose B-J-F (1993/4)

 

X. Goula: Seismic hazard assessment in Spain: New developments in Catalonia

 

·        Spanish code based on seismic hazard studies of Martin 1984

§         Catalog and seismotectonic zones poorly defined

§         PSHA approach (McGuire, 1976)

§         Accelerations deduced from intensity maps

§         Attenuation relationship deduced from isoseismal lines of major earthquakes

§         Elastic response inferred for three soil types

§         Granada, Andalucia (Southern Spain) have highest hazard

·        Building Code is currently being updated

§         Minor revision of eq cat

§         Same seismotectonic zonation

§         Same attenuation relationship

§         New spectral forms for soft soils

·        New catalog of Catalonian seismicity available

§         Combined from 4-5 catalogs

§         Includes historical earthquakes

§         Published by his institute and available on their website

·        Seismotectonic zonation based on available geophysical/geological data

 

Antonio Roca: Evaluation of seismic vulnerability of dwelling buildings in Catalonia, Spain

 

·        A method for preliminary evaluation of seismic vulnerability of dwelling buildings was developed and applied to the area of Catalonia in order to evaluate earthquake risk for emergency plans.

§         6.1 million people, 1 million buildings, 841 towns in Catalonia

§         Objective: Preparation and activation of emergency plans

§         Based on the European Macroseismic Scale (EMS-98) plus parameters easily available in the building census (location, age, and number of floors)

§         Methodology: Classification of risk, estimation of damage, assessment of human casualties, evaluation of economic losses

§         webpage at www.icc.es

§         Can also be used to generate damage scenarios

Ø      Recurrence of 1428 earthquake in Ripolles would result in 1600 killed, 135,000 homeless, 26,000 injuries

·        New broadband VSAT real time seismological network

§         Provides Civil Defence centres with fast estimation of effects just after an event is detected and located by the network

·        Future plans: Use the vulnerability database with a real-time strong-motion network to make real-time estimates of damage patterns

·        Project RISK-EU

§         Years 2001-3

§         Earthquake risk scenarios for European Union towns

 

Sultan Al-Shaabi: Changes in b-value prior to large earthquakes in the Gulf of Aqaba

 

·        During the last fifteen years, the Gulf of Aqaba is one of the most seismically active zones in the Middle East region

§         Seismicity is intense in the Gulf 1985-1996

§         Sequences in 1983, 1990-1, 1993 and 1995

§         July 1993foreshock and many aftershocks, concentrated near BMSH (KSU station)

§         1990, May 1991 swarms M>4.0 in Southern Gulf of Aqaba

§         1415 events compiled using data from the KSU network and the adjacent neighboring networks

Ø      Time span: 1985 – 1995

Ø      Area: Latitude 28°-30° N, longitude 34°-36° E

Ø      Duration magnitudes > 2.8

·        b-value in the Gutenberg-Richter relation investigated

§         Maximum likelihood method was used

§         b-value has apparently increased sharply (1.46±0.21) before the mainshock-aftershock sequence type

§         Moderate and steady increase in the b-value (0.98±0.14) occurs before the foreshock-mainshock-aftershock sequence

·        Conclusion: b-value temporal variation may be an effective method for predicting earthquakes in the area of interest—supports of observation of Smith (1986) that the b-value is a medium term precursor of earthquakes

 

Salah El-Hadidy Aly Youssef: The Role of the Egyptian National Seismological

Network in the better understanding of the seismicity in Egypt and surrounding countries

 

·        Seismicity of Egypt is mostly in the northeast near Cairo, Sinai, and Aqaba

§         20 million people in greater Cairo area

§         Historical seismicity (Ambrases 1994) follows instrumental trends

·        Seismicity before 1980 only from historical or WWSSN (Helwan) instrumentation

·        Activity near the Aswan Dam after dam was filled

§         Ali Gharib studied this activity

§         1981-1990: Aswan Dam (Nasser Lake) activity concluded to be tectonic

·        Additional activity in Eastern Desert probably due to new stations

·        KEG started 1990, now replaced with a new NRIAG instrument (STS-2)

·        Project to study seismic hazards along the Gulf of Aqaba and around Aswan

§         UNESCO funded

§         Need data from Saudi Arabia to improve the locations in the Gulf

§         Abou Elenean (1997) produced focal mechanisms

·        Seismic refraction studies

§         Started in 1972 in cooperation with Makris

§         Many profiles from the Eastern Desert and Sinai

§         Aswan also covered

§         Western Desert poorly covered

§         Crustal thickness about 28 km in Eastern Desert, thickens to west

·        Surface wave dispersion at KEG for Mediterranean Sea, Continental paths

§         Seismic P-wave tomography around KEG

§         100 well-located events

§         Aftershock activity lies along the edges of low velocity body in the middle crust

§         This body corresponds with a gravity low, possibly related to the basaltic flow

§         The Cairo earthquake aftershocks are broadly distributed and it’s hard to associate them with specific faults

 

Abdul El-Ala Amin Mohammed Sayed Ahmed: Seismotectonic and earthquake hazard studies in Egypt

 

·        Egypt concerned about Nile Valley because of population and development

§         Seismic hazard and vulnerability increasing due to urbanization and development in earthquake prone areas

§         Microzonation map for Egypt

Ø      Seismic environment

Ø      Seismotectonic model and seismic parameters of the faults

Ø      Geology

Ø      Soils

Ø      Seismic response

Ø      Amplification, resulting intensity

§         Maximum intensity zonation map

Ø      Maximum intensity in Aqaba

§         Isoseismal intensity maps for a number of events

 

 


 

Earthquake Hazard Assessment Practice and Velocity Models and Reference Events in the Mediterranean Region

 

Santa Susanna, Spain, 20-25 May 2001

 

Participant List

 


Abdel Qader Fandi Abdullah

Natural Resources Authority

Jordan Seismological Observatory

P.O. Box 7

Amman, Jordan

Tel. 962 6 582 7970, 962 6 523 2105

Fax 962 6 581 1866, 962 6 582 7970

jso@nic.net.jo

 

Abdul El-Ala Amin Mohammed Sayed Ahmed

National Research Institute of Astronomy and Geophysics

Helwan Cairo, Egypt

Tel.      20 2 550-2500, 012 366 9967

Fax      202‑554-3111, 202-554‑8020

abuoelela99@hotmail.com                   

Jalal N. Al‑Dabbeek

Earth Sciences & Seismic Engineering Center

An‑Najah University

P.O. Box 7 Nablus, The Palestinian Authority

Tel.      972 9 238 3121    238 1115

Fax      972 9 238 7982          

seiscen@najah.edu

 

Mohammad Al Haddad

King Saud University

College of Engineering

P.O. Box 800

Riyadh 11421, Saudi Arabia

Tel.      9661 468 3467

Fax      9661 468 1078

alhaddad@ksu.edu.sa


Tariq Al-Kalifah

Institute for Astronomy and Geophysical Research

King Abdulaziz City for Science and Technology

PO Box 6006

Riyadh 11442, Saudi Arabia

Tel.      966 1 481 3555 x1315

Fax      966 1 481 3526          

tkhalfah@kacst.edu.sa

 

Nasser Al-Mukhadry

National Seismological Observatory Center

P.O. Box 87370

Dhamar, Republic of Yemen

Tel.      967 6 505895; 976 6 505634

Fax      967 6 502519             

nsoc@y.net.ye

 

Yesim Alpay-Biro

Kandilli Observatory and Earthquake Research Institute

Bogazici University

81220 Cengelkoy

Istanbul, Turkey

Tel.      90 216 308 0522 ext 366

Fax      90 216 308 0163, 332 1711

alpayye@boun.edu.tr

 


Sultan F. Al-Shaabi

Seismic Studies Centre

King Saud University

PO Box 61119

Riyadh 11565, Saudi Arabia

Tel.      966 1 467 6350

Fax      966 1 467 6345          

alshaabi@hotmail.com

 

Gunruh Bagci

General Directorate of Disaster Affairs

Ministry of Public Works and Settlement

06530 Ankara, Turkey

Tel.      90 312 287 3648

Fax      90‑312‑285-5304       

bagci@deprem.gov.tr

 

Basel Ballani

General Establishment of Geology and Mineral Resources (GEG)

P.O. BOX 7645 Geomineral

Damascus, Syria

Tel.      963 11 442 0780

Fax      963 11 442 9197        

basel68@gmx.co.uk, geo@net.sy

 

Nabil Zaki Basta

Egyptian Geological Survey and Mining Authority

Cairo, Egypt

Tel.      20 2 688040, 20 2 493 3157

Fax      20 2 482 0128

egsma@idsc.gov.eg     

 

Djillali Benouar

Université d’Alger (USTHB)

Civil Engineering Department

BP32 El-Alia

BabEzzouar

Alger, 16111, Algérie

Tel.      213 21 247914

Fax      213 21 247914/247224

d

benouar@yahoo.com

 

Ina Cecic

Ministrstvo za okolje in prostor

Agencija RS za Okolje

Dunajska 47/VI

Si-1000 Ljubljana, Slovenia

Tel.      386 1 478 7265

Fax.     386 1 478 7295

ina.cecic@gov.si

 

Sidi Otman El Alami

Université Mohamed V

Institut Scientifique

Departement de Physique du Globe

BP 703

Agdal, Rabat, Morocco

Tel.      212 6 508 8729

Fax      212 777 4540             

elalami@israbat.ac.ma

 

Salah El-Hadidy Aly Youssef

National Research Institute of Astronomy and Geophysics

Helwan Cairo, Egypt

Tel.      202‑554-3111, 20 2 253 0924, 012 367 0102

Fax      20 2 556-554‑8020

Saall96@yahoo.com, saall96@netscape.com

           

Ramy El‑Khoury

Rafik El‑Khoury & Partners Consulting Engineers

c/o Sin El‑Fil Horch Tabet

Awad Bldg

Beirut, Lebanon

Tel.      961 1 493150/1, 961 1 488250/1/2

Fax      961 1 493150/1, 961 1 488250/1/2                

relk&p@dm.net.lb

 


Radwan El‑Kelani

Earth Sciences & Seismic Engineering Center

An‑Najah National University

P.O. Box 707, Nablus, The Palestinian Authority

Tel.      972 9 238 3121

Fax      972 9 238 7982          

seiscen@najah.edu

 

Jeannette Fernandez

Facultad de Ingenieria Civil

Escuela Politecnica Nacional

Quito, Ecuador

Tel.      593 2 563 077

Fax      593 2 567 847            

janet@server.epn.edu.ec

, gfernand@uio.satnet.net

 

Michael P.  Foose

U.S. Geological Survey

917 National Center

Reston VA 20192, USA

Tel.      1 703 648 6055

Fax      1 703 648 4227          

mfoose@usgs.gov

 

 

Mariano Garcia-Fernandez

Instituto de ciencias de la Tierra “Jaume Alera” CSIC

Lluis Sole i Sabaris s/n

E-08028 Barcelona, Spain

Tel.      34 93 409 5410

Fax      34 93 411 0012          

mgarcia@ija.csic.es

 

Hadi E. M. Gashut

General Director

Libyan Center for Remote Sensing and Space Science

Tripoli, Libya

Tel.      218 21 4900885

Fax      218 21 4909053         

hadi_gashut@yahoo.com

 


Xavier  Goula

Geological Survey

Institut Cartografic de Catalunya

Parc de Montjuic

E-08038 Barcelona, Spain

Tel.      34 93 567 1500

Fax      34 93 567 1567          

goula@icc.es

 

Polat Gulkan

Department of Civil Engineering

Orta Dogu Teknik Universitesi

Middle East Technical University

06531 Ankara, Turkey

Tel. 90 312 210 2446 

Fax 90 312 210 1262, 90 312 210 1193

a03516@metu.edu.tr

 

 

Mohamed Hamdache

Centre de Recherche en Astronomie, Astrophysique et Géophysique (CRAAG)

BP 63

Bouzareah 16340

Alger, Algérie

Tel.      213 21 90 44 55/56

Fax      213 21 90 44 58         

mhamdache@hotmail.com

 

 

Walter Hays    

American Society of Civil Engineers

1801 Alexander Bell Drive

Reston, VA 20192-4400, USA

Tel.      1 703 295 6054

Fax      1 703 295 6141          

whays@asce.org

 


Rami Hofstetter

Geophysical Institute of Israel

P.O. Box 182

HaBaal Shem-Tov St., North Industrial Zone

Lod 71100, Israel

Tel.  972 8 978 5851

Fax 972 8 925 5211, 972 8 920 8811

rami@iprg.energy.gov.il

 

Maria Jose Jimenez

Instituto de ciencias de la Tierra “Jaume Alera” CSIC

Lluis Sole i Sabaris s/n

E-08028

Barcelona, Spain

Tel.      34 93 409 5416

Fax      34 93 411 0012

mjjimenez@ija.csic.es              

Rachid Jomaa

National Council for Scientific Research

National Center for Geophysics

P.O. Box 16‑5432

Beirut, Lebanon

Tel.      961 4 981885/6

Fax      961 4 981886; 961 1 822639

geophys@cnrs.edu.lb

 

Khaled Kahhaleh

Building Research Center

Royal Scientific Society

Amman, Jordan

Tel.      962 6 534 4701/ext.750

Fax      962 6 534 7399          

kahhaleh@rss.gov.jo

 


Nacer Laouami

Centre National de Recherche Appliquée en Genie Parasismique (CGS)

rue Kaddour Rahim

B.P. 252, Hussein Dey

Alger, Algérie

Tel.      213 2 495547/48/49/60/61/62

Fax      213 2 495536/37        

Cgsd@wissal.dz;

 

nasser_laouami@excite.fr

 

Gideon Leonard

Israeli Atomic Energy Commission

PO Box 7061

Tel Aviv, Israel

Tel.      972 3 646 2955

Fax      972 3 646 2539          

gidon@soreq.gov.il; gidon@ndc.soreq.gov.il

 

Josseph Leonov

Geophysical Institute of Israel

P.O. Box 182

HaBaal Shem-Tov St., North Industrial Zone

Lod 71100, Israel

Tel. 972 8 978 5851, 972 8 978 5847

Fax 972 8 925 5211, 972 8 920 8811

jossleon@gii.co.il

 

Soren Malling

United Nations Educational, Scientific and Cultural Organization

7 Place de Fontenoy

75007 Paris, France

Tel.      331-4568-4122

Fax      331-4568-5822          

s.malling@unesco.org

 


Gilles Mazet-Roux

Centre Sismologique Euro‑Mediterraneen

c/o LDG BP 12

91680 Bruyeres‑le‑Chatel, France

Tel.      33 1 6926‑7813

Fax      33 1 6926‑7000

mazet@emsc-csem.org

 

Keith McLaughlin

Center for Monitoring Research

Suite 1450

1300 N. 17th Street

Arlington, VA 22209, USA

Tel.      1 703 247 4135

Fax.     1 703 524 2073

scatter@cmr.gov

 

Maen Mrech

General Establishment of Geology and Mineral Resources (GEG)

P.O. BOX 7645 Geomineral

Damascus, Syria

Tel.      963 11 442 0780

Fax      963 11 442 9197                    

Keith Nakanishi

Lawrence Livermore National Laboratory L‑205

Livermore, CA 94550, USA

Tel.      1 925 422 3923

Fax      1 925 423 4077          

nakanishi1@llnl.gov

 

 

Batia Reich

Geophysical Institute of Israel

P.O. Box 182

HaBaal Shem-Tov St., North Industrial Zone

Lod 71100, Israel

Tel.  972 8 978 5853/4

Fax 972 8 925 5211, 972 8 920 8811

batia@gii.co.il

 


Florence Riviere

Centre Sismologique Euro‑Mediterraneen

c/o LDG BP 12

91680 Bruyeres‑le‑Chatel, France

Tel.      33 1 6926‑7813

Fax      33 1 6926‑7000

riviere@emsc-csem.org

 

Antony Roca

Geological Survey

Institut Cartografic de Catalunya

Parc de Montjuic

E-08038 Barcelona, Spain

Tel.      34 93 567 1500

Fax      34 93 567 1567          

roca@icc.es

 

Artie Rodgers

Lawrence Livermore National Laboratory

Livermore  CA 94550, USA

Tel.      1 925 423 5018

Fax      1 925 423 4077          

rodgers7@llnl.gov

 

Robert T. Sewell

R. T. Sewell Associates, Consulting

500 Orchard Drive

Louisville, CO 80027, USA

Tel.      1 303 665 2731

Fax      1 303 665 2731

rtsewell@aol.com

 

Avi Shapira

Geophysical Institute of Israel

P.O. Box 182

HaBaal Shem-Tov 6, Industrial Zone North

Lod 71100, Israel

Tel. 972 8 978 5853/4

Fax 972 8 925 5211, 972 8 920 8811

avi@gii.co.il

 


M. Jamal M. Sholan

National Seismological Observatory Center

P.O. Box 87175

Dhamar, Republic of Yemen

Tel.      967 6 505094; 976 6 505634

Fax      967 6 502519

sholan12@Y.Net.Ye

 

Frederick O. Simon

11813 Stuart Mill Road

Oakton, VA 22124-1227, USA

Tel.      1 703 620 2772

Fax      1 703 620 2772          

fsimon@erols.com

 

 

Dario Slejko

Instituto Nazionale di Oceanografia e di Geofisica Sperimentale

Borgo Grotta Gigante 42c, 34010 Sgonico

Trieste, Italy

Tel.      39 040 214 0248

Fax      39 040 327307           

dslejko@ogs.trieste.it

 

Douglas Smith

Department of Geological Sciences

University of Florida

Gainesville, FL 32611, USA

Tel.      1 352 392 6766

Fax      1 352 392 9294          

dlsmith@geology.ufl.edu

 

Kyriacos Solomi

Geological Survey Department of Cyprus

Nicosia 1415, Cyprus

Tel.      357 2 309265

Fax      357 2 316873             

gsd@cytanet.com.cy

 


Ben Aissa Tadili

Université Mohamed V

Institut Scientifique

Departement de Physique du Globe

BP 703

Agdal, Rabat, Morocco

Tel.      212 6 239 2390

Fax      212 777 4540 

tadili@israbat.ac.ma

 

Torild Van Eck

ORFEUS c/o Seismology Division

Royal Netherlands Meteorological Institute

3730 AE De Bilt, The Netherlands

Tel.

Fax      31 30 2201 364          

vaneck@knmi.nl

 

Maria Yeroyanni

European Commission

DG Research

200 Rue de la Loi SDME 7/39

1049 Brussels, Belgium

Tel.      32 2 295 8512

Fax      32 2 296 3024            

marie.yeroyanni@cec.eu.int

 

Mehdi Zare

International Institute of Earthquake Engineering and Seismology

P.O. Box 19395/3913

Tehran, I.R. Iran

Tel.      98 21 283 111619, 98 911 200 7813

Fax    98 21 229 9479, 98 21 701569

mzare@dena.iiees.ac.ir, mzare@altavista.fr

 


Annex B

 

Earthquake Hazard Assessment Practice and Velocity Models and Reference Events in the Mediterranean Region

 

Santa Susanna, Spain, 20-25 May 2001

 

Programme

 

Sunday, 20 May 2001

 

Arrive in Santa Susanna

 

Registration

 

Opening Session

 

1930 – 2030    Session chaired by Mariano Garcia-Fernandez

                        Xavier Fuster, CSIC

                                    M. Garcia-Fernandez, Instituto de Ciencias de la Tierra 'Jaume Almera' - CSIC

                        S. Malling, UNESCO

                        F. Riviere, EMSC

                        M. Foose, USGS

                       

                                                Invited Dinner Speaker: Maria-Jose Jimenez: The Unified Seismic Hazard Map of Europe and the Mediterranean

 

2030             Workshop Dinner

 

 

Monday, 21 May 2001

 

Velocity Models and Reference Events in the Mediterranean Region

 

0930 – 1000    K. McLaughlin, Use of Reference Events to Validate 3-D Models in the Mediterranean Region for Location Calibration

1000 – 1030    Torild van Eck: ORFEUS and MERIDIAN

1030 – 1100    A. Shapira: Travel-time modelling in the Middle East

 

1100 – 1130    Coffee/tea break

 

1130 – 1200    A. Rodgers and A. Al-Amri:  Seismic velocity models and ground truth development in the Arabian Peninsula: A U.S.-Saudi Arabian cooperative project

1200 – 1230    K. Nakanishi: Data sharing in the EMR

1230 – 1300    Hadi Gashut: Earthquake activity in Libya and the importance of the Libyan National Seismograph Network

 

1300 – 1400    Lunch

 

Earthquake Hazard Assessment in the Mediterranean Region

 

1400 – 1430    D. Slejko: Hazard Assessment Practice in Italy

1430 – 1500    A. Shapira: Hazard Assessment Practice in the Middle East and Application to Building Codes

1500 – 1530    Y. Alpay-Biro: Current developments for seismic hazard assessment for Istanbul and Marmara region

 

1530 – 1600    Coffee/tea break

 

1600 – 1630    Polat Gülkan:    Source modelling and seismological properties of the recent Turkey Earthquakes

1630 – 1700    Maria Yeroyanni: The Mediterranean Disaster Information Network (MEDIN)

1700 – 1730    I. Cecic: The European Seismological Commission Field Investigation Team (FITESC)

           

                        Dinner – Open

           

 

Tuesday, 22 May 2001

 

Earthquake Hazard Assessment in the Mediterranean Region

 

0930 – 1000    Benouar: A review of the earthquake data bank in western Mediterranean countries (Algeria, Morocco, Tunisia)

1000 – 1030    Mehdi Zare: Recent Developments in Iranian Seismic Hazard Studies

1030 – 1100    Mehdi Zare: Urban Development and Construction Along North Tabriz Fault Zone in NW Iran: A Field Visit Report (May 2001)

 

1100 – 1130    Coffee/tea break

 

Velocity Models and Reference Events in the Mediterranean Region

 

1130 – 1200    F. Riviere: Contribution of the EMSC-CSEM to Earthquake Hazard Assessment Practice in the European-Mediterranean region

1200 – 1230    Gideon Leonard: Model inaccuracy and bias in hypocenter estimation

1230 – 1300    Tariq Al-Khalifah: Saudi National Seismic Network

 

1300 –1400     Lunch

 

Earthquake Hazard Assessment in the Mediterranean Region

 

1400 – 1430    Djillali Benouar: Hazard Mapping in Algeria

1430 – 1500    Mohammed Al-Haddad: Seismic Microzonation in Saudi Arabia

1500 – 1530    Jalal Al-Dabbeek and Abdel-Hakeem Jawhari: Palestinian Common Buildings and Variation in Seismic Building Codes

1530 – 1600    Ramy El-Khoury: Examples of earthquake resisting system in Lebanon

 

1600 – 1630    Coffee/tea break

 

Earthquake Hazard Assessment in the Mediterranean Region

 

1630 – 1700    Polat Gülkan:  Near-field ground motion effects and their correlation with structural damage

1700 – 1730    Jeannette Fernandez: The Global Earthquake Safety Initiative (GESI)

1730 – 1800    Gideon Leonard: Seismic Hazard Assessment: Simultaneous effect of earthquakes at close and distant sites

 

                        Dinner – Open

 

Wednesday, 23 May 2001

 

Seminar on Probabilistic Seismic Hazard Assessment

 

0900 – 1800    R. Sewell: Probabilistic Seismic Hazard Assessment and the use of FRISKSP software

 

1030 – 1100    Coffee/tea break

 

1300 – 1400    Lunch

 

1600 – 1630    Coffee/tea break

 

                        Dinner – Open

 

 

Thursday, 24 May 2001

 

Field trip        

 

0900 – 1800    ‘La Garrotxa’ volcanic field, the Volcano Museum of Olot, and the area affected by the XVth century damaging earthquake series.

 

 

 

Friday, 25 May 2001

 

Earthquake Hazard Assessment in the Mediterranean Region

 

0930 – 1000    X. Goula: Seismic hazard assessment in Spain: New developments in Catalonia

  1000 – 1030  Antonio Roca: Evaluation of seismic vulnerability of dwelling buildings in Catalonia, Spain

1030 – 1100    Sultan Al-Shaabi: Changes in b-value prior to large earthquakes in the Gulf of Aqaba

 

1100 – 1130    Coffee/tea break

 

1130 – 1200    Salal El-Hadidy Aly Youssef: The Role of the Egyptian National Seismological Network in the better understanding of the seismicity in Egypt and surrounding countries

1200 – 1230    Abdul El-Ala Amin Mohammed Sayed Ahmed: Seismotectonic and earthquake hazard studies in Egypt

 

1300 –1400     Lunch

 

Panel discussions

 

1400 – 1800    Panel discussion on Earthquake Hazard Assessment in the Mediterranean Region

                       

Panel discussion on Velocity Models and Reference Events in the Mediterranean Region

 

Closing Ceremony

 

1530 – 1600    Coffee/tea break

 

                        Dinner – Open


 

Annex C

 

Abstracts

 

Unified seismic hazard model for the European-Mediterranean region

 

M.-J. Jimenez1, 2 and D. Giardini1

1Swiss Seismological Service, ETHZ, Switzerland

2Inst. of Earth Sciences-CSIC, Barcelona, Spain

 

 

Over the past eight years several projects have aimed at the establishment of improved global and regional seismic hazard assessment and a number of multinational programs were set up to produce earthquake catalogues, seismic source zoning and hazard assessment in the European-Mediterranean region. As part of the GSHAP global hazard map, the first map for the European-Mediterranean region in terms of ground acceleration was produced in 1999. While this map was based on the compilation of the hazard results of different test areas and national and multinational programs active in Europe and the Mediterranean, this paper presents the development and results of  the first homogeneous assessment of seismic hazard for the whole European-Mediterranean region through the seismotectonic probabilistic approach.

 

The whole European-Mediterranean region has then been unified within three project frameworks: (1) the Global Seismic Hazard Assessment Program (GSHAP), a UN/IDNDR demonstration program, which produced in 2000 the first global map of seismic hazard in terms of ground acceleration; (2) the IGCP-382 project SESAME which has completed a more detailed, integrated seismic source model and hazard mapping for the Mediterranean region; and (3) the European Seismological Commission (SC-F/WG SHA), through the integration of regional results to obtain a unified seismogenic source model and homogeneous hazard assessment procedure for the whole European-Mediterranean region.

 

For the first time a comprehensive model of hazard assessment for the whole European-Mediterranean region has been developed which allows the generation of hazard maps, expressing ground motion in different parameters (peak ground acceleration, 0.3s and 1.0s spectral acceleration),  for different soil condition (rock, stiff soil) and different probability levels (1%, 10% and 65% of exceedance in 50 years). A suite of final hazard maps for the whole European-Mediterranean region are been published in 2001 as a closing activity of the ESC/SC-F Working Group on Seismic Hazard Assessment.


Palestinian Common Buildings and Variation

in Seismic Building Codes

 

 

Jalal Al-Dabbeek and Abdel-Hakeem Jawhari

Earth Sciences & Seismic Engineering Center

An-Najah National University

Nablus Municipality

 

 

Introduction

 

Building codes are intended to provide guidelines and formulas that constitute minimum legal requirements for design and construction within a particular region, the preparation of design codes is a dynamic process, in which experts in a field share their experience in research and practical problems to set guide lines for design engineers to follow.

 

The basic principle of any design is that “The product should meet the owner’s requirements.” cost, function and reliability.

 

The main objective of a code is to protect life, health, and property by regulating and controlling the design construction, quality of materials, use and occupancy, location and maintenance of all buildings and structures.

 

The code provisions for design and construction of structures using the equivalent static load method are different depending on the specific situation of each country.  This includes different parameters such as: the expected horizontal ground acceleration, site effects (geology and types of soil), importance factor of the structure, and the parameters relating the structural response of buildings “fundamental period of vibration of the structure and force reduction factor or ductility factor”.  In addition, quality control, level of detailing, and construction techniques have also an effect.

 

Next, we present a brief description of the effect of applying different code parameters on the values of the base shear coefficient.

 

Methodology

 

The horizontal seismic forces at the base and the base shear coefficient are calculated considering the following:

 

The building height:  4 stories and 10 stories

 

The structural system:                        Ductile moment resisting frame  Moment resisting frame

Braced frame                                        Shear wall

Bearing wall

 

Construction Methods:  Different construction methods were considered for both 4 and 10 stories.

 

Codes Considered:  The calculations for base shear coefficient were done according to different regional and international codes: Arab, Algeria, Argentina, Bulgaria, Chile, China, Egypt, Hungary, India, Indonesia, Iran, Israel, Jaban, Mexico, Newzeland, Romania, Turkey, United States of America (uniform building code 85, 94 and 97), and Former Yugoslavia.

 

Procedure

 

It is known that each of the parameters and for each code, there could be an effect on the values obtained for the base shear coefficient (horizontal seismic force). To minimize the variation expected, the following assumptions are adopted:

 

·        The parameters relating the soil (site effect) horizontal ground acceleration and the importance of structure are fixed.

 

·        The parameters of the fundamental period and the nature of the structural response which depend on the dimensions of the building, structural system, material used, and the method of construction are considered to be variable (using the same material and dimensions of buildings, and variable structural system) to find their effect.

 

Results

 

Considering the previously-mentioned different parameters and applying different codes, the results were variable and can be described as follows:

·        There is a variation in the results when applying a given code’s code formula for the same building but considering different structural types.

·        The results are also variable when applying different codes for the same building and the same structural case.

·        There are big variations in the results and sometimes up to double the values, between different codes when considering methods of construction and material variation.

·        The largest variation among approaches adopted to define seismic base shear by different countries lies in the value of the force reduction coefficient assigned to different structural and material types.


 

 

Code

DMRF

MRF

BF

SW

BW

4 Story

10 Story

4 Story

10 Story

4 Story

10 Story

4 Story

10 Story

4 Storey

10 Storey

Zone

Zone

Zone

Zone

Zone

Zone

Zone

Zone

Zone

Zone

Zone

Zone

Zone

Zone

Zone

Zone

Zone

Zone

Zone

Zone

2

3

2

3

2

3

2

3

2

3

2

3

2

3

2

3

2

3

2

3

Arabic

 

 

 

 

0.039

0.078

0.029

0.058

 

 

 

 

 

 

 

 

0.078

0.158

0.058

0.116

Algeria

0.083

0.124

0.045

0.067

0.083

0.124

0.045

0.067

0.1

0.15

0.06

0.09

0.136

0.204

0.083

0.124

0.268

0.39

0.163

0.24

Argentina

0.166

0.204

0.09

0.11

0.166

0.204

0.09

0.11

0.25

0.3

0.137

0.168

0.273

0.335

0.137

0.167

0.306

0.376

0.16

0.205

Bulgaria

0.09

0.135

0.036

0.054

0.09

0.135

0.036

0.054

0.15

0.225

0.102

0.153

0.125

0.187

0.085

0.13

0.25

0.375

0.17

0.255

Chile

0.064

0.064

0.030

0.03

0.08

0.08

0.038

0.038

0.1

0.1

0.10

0.10

0.12

0.12

0.12

0.12

0.12

0.12

0.12

0.12

Columbia

0.060

0.091

0.037

0.0575

0.091

0.136

0.058

0.058

0.168

0.214

0.093

0.108

0.147

0.187

0.081

0.092

0.393

0.5

0.210

0.324

Egypt

0.135

0.202

0.1

0.113

0.2

0.3

0.1

0.15

0.24

0.36

0.18

0.225

0.2

0.3

0.15

0.225

0.32

0.48

0.24

0.27

Greece

0.17

0.255

0.13

0.195

0.17

0.255

0.13

0.195

0.2

0.3

0.17

0.255

0.2

0.3

0.17

0.255

0.4

0.6

0.35

0.51

Hungary

0.137

0.2

0.074

0.108

0.137

0.2

0.074

0.108

 

 

 

 

0.19

0.28

0.14

0.204

 

 

 

 

 Zone 2 and 3 according to UBC 

 

 

Code

 

 

DMRF

MRF

BF

SW

BW

4 Storey

10 Storey

4 Story

10 Story

4 Story

10 Story

4 Story

10 Story

4 Story

10 Story

Zone

Zone

Zone

Zone

Zone

Zone

Zone

Zone

Zone

Zone

Zone

Zone

Zone

Zone

Zone

Zone

Zone

Zone

Zone

Zone

2

3

2

3

2

3

2

3

2

3

2

3

2

3

2

3

2

3

2

3

India

 

0.037

0.055

0.022

0.034

0.037

0.055

0.02

0.034

0.052

0.078

0.039

0.059

0.064

0.096

0.048

0.072

0.064

0.096

0.048

0.072

Indonesia

 

0.05

0.07

0.04

0.065

0.05

0.07

0.04

0.065

0.125

0.137

0.113

0.17

0.06

0.084

0.054

0.082

0.125

0.175

0.113

0.17

Iran

 

0.037

0.055

0.023

0.035

0.037

0.055

0.023

0.035

0.057

0.086

0.034

0.051

0.057

0.086

0.034

0.051

0.11

0.165

0.06

0.09

Israel

 

0.058

0.086

0.044

0.066

0.101

0.152

0.063

0.09

0.14

0.21

0.11

0.162

0.101

0.152

0.11

0.162

 

 

 

 

Japan

 

0.15

 

0.135

 

0.15

 

0.135

 

0.15

 

0.135

 

0.15

 

0.135

 

0.15

 

0.135

 

 Jordan

 

0.043

0.066

0.058

0.087

0.043

0.066

0.058

0.087

0.087

0.13

0.173

0.26

0.087

0.076

0.173

0.26

0.113

0.168

0.2

0.3

New Zealand

0.036

0.054

0.02

0.03

0.066

0.099

0.04

0.06

 

 

 

 

0.066

0.099

0.036

0.054

 

 

 

 

Romania

 

0.1

0.15

0.1

0.15

0.1

0.15

0.1

0.15

 

 

 

 

0.125

0.187

0.125

0.187

0.15

0.225

0.12

0.225

Turkey

 

0.085

 

0.052

 

 

 

 

 

0.13

 

0.08

 

0.098

 

0.067

 

0.185

 

0.126

 

UBC 85

 

0.026

0.053

0.017

0.034

 

 

 

 

0.032

0.063

0.020

0.040

0.045

0.09

0.031

0.062

 

 

 

 

UBC 88

 

0.033

0.05

0.021

0.032

0.04

0.06

0.025

0.038

0.05

0.075

0.032

0.047

0.131

0.197

0.083

0.124

0.087

0.131

0.055

0.083

UBC 97

 

0.033

0.021

 

 

0.073

0.11

0.037

0.055

0.073

0.108

0.036

0054

0.1

0.152

0.051

0.076

0.135

0.2

0.067

0.1

Yugoslavia

 

0.05

0.10

0.04

0.08

0.05

0.10

0.04

0.08

0.065

0.13

0.05

0.1

0.065

0.13

0.05

0.1

0.1

0.2

0.078

0.156

 Zone 2 and 3 according to UBC


Changes in b-value prior to large earthquakes

in the Gulf of Aqaba

 

Sultan Al-Shaabi

Seismic studies Center, King Saud University

Riyadh 11451, Saudi Arabia

 

 

During the last fifteen years, the Gulf of Aqaba has been considered as one of the most seismically active zones in the Middle East region. A catalogue of 1415 events were compiled using the available data from the Seismic Studies Center Network of King Saud University, and the adjacent neighboring networks. The data cover the time span between 1985 to 1995 and an area located between latitude 28°-30° N, longitude 34°-36° E. The duration magnitudes for these earthquakes were equal to or greater than 2.8.

 

In this paper we investigate the value of b in the Gutenberg-Richter relation for a local earthquakes catalogue. The maximum likelihood method was used in this study and the b-value has apparently increased sharply (1.46±0.21) before the mainshock-aftershock sequence type which was accompanied by a period of quiescence. Also, a moderate and steady increase in the b-value (0.98±0.14) occurs before the foreshock-mainshock-aftershock sequence type. Monitoring suggests that b-value temporal variation may be an effective method for predicting earthquakes in the area of interest.


Earthquake hazard assessments in the Eastern Mediterranean Region – A short review

 

Avi Shapira

Geophysical Institute of Israel

 

The Middle East and the East Mediterranean Region are vulnerable to earthquakes. We recently experienced the disasters in Egypt, Iran and Turkey and a similar fate is expected for the countries surrounding the active Dead Sea Transform – unless we take care of mitigating the risk by reducing the vulnerability of the buildings.  In spite of the significant improvements in seismic monitoring of the region over the last years, we still are not clear about the hazard around major cities such as Beirut, Amman and Cairo. The seismic activity in the eastern Mediterranean Sea, that will affect the population along the coast from Turkey to Egypt, is not well defined.

 

The most commonly used practice for hazard assessment is the implementation of the Cornel-McGuire approach for the estimation of the PGA under hard-rock conditions. In many cases, the computations involve using PGA attenuation functions that are copied from other regions. In many cases we have no chance to test the function against actual local data. The Gulf of Aqaba earthquake in 1995 excited some the accelerometers in Israel and, after careful analysis, we have concluded that the equation of Boore et al. 1994 will best fit the observed accelerations.

 

An important development in improving hazard assessments is the uniform earthquake catalog that is compiled jointly by NRA (Jordan) and GII (Israel). This work, facilitated through a USAID-MERC grant, also results in preparing a new seismogenic zone map for the EMR.

 

The next step is to evaluate seismic hazards that take into consideration the site effects. First attempts have already been executed in Iran and Israel. More elaborated techniques, using simulations of strong ground motion, have also been tested. Preliminary results show agreement between simulated and measured acceleration response spectra.

 


Travel-time models and location analysis based on the Dead Sea calibration experiment

 

Presented by Avi Shapira on behalf of GII (Israel), NRA (Jordan) and GSD (Cyprus)

 

The Dead Sea calibration experiment in November 1999, provids a unique opportunity to evaluate local travel-time models and their effect on accurate location capabilities. The underwater explosions of 500, 2000 and 5000 kg provided very accurate local travel-time data at distances of up to 500 km. This range includes seismic stations in Cyprus (CSN), Lebanon, Syria, Israel (ISN), Jordan (JSN) and Saudi Arabia (compiled during the RELEMR meeting in Turkey, 2000). The preliminary analysis of the travel time data showed that:

·        The velocity model used by GII to locate seismic events in and around Israel yields accurate travel time estimations.

·        The phase picking (first P wave) scatter/uncertainty is in the range of 0.2-0.3 sec. The average value of 0.26 sec is obtained under ideal conditions: Same detonation point and accurate time measurements of the 3 explosions, recorded by the same stations, and a fair knowledge of the expected arrival times.

·        The velocity structure of the crust across the Middle East and the East Mediterranean differs significantly from place to place.

 

Using the reported travel times of the Dead Sea experiment we have constructed three 1-D travel-time (TT) models:

(a)    For the stations west to the Dead Sea transform fault, i.e., the CSN (Cyprus) and the ISN (Israel).

(b)   The stations east to the transform fault (mainly readings of the Jordanian Seismic Network).

(c)    For stations of ISN, CSN and JSN.

 

The differences in local travel times, computed by the three models, are smaller than the expected uncertainty of phase picking.

 

In an attempt to examine the effect of the travel-time models on location capabilities, we re-located the Dead Sea explosions using 8 different 1-D travel-time models: The old GII model, the three new models (see above), travel-time models proposed previously  by the Geological Survey of Egypt, by the Seismology Division of the NRA (Jordan), by LLNL and an arbitrary model consisting of one 33-km thick layer of Vp=6 km/s overlaying a half space with Vp=8 km/s.

 

As expected, the epicenter in all cases was located within 3 km. from the true location, indicating that for epicenter determination, a good distribution of stations is more important than an accurate travel-time model. Focal depth determinations are more sensitive to uncertainties or errors in the travel-time model.  Based on these results we may assume that the new regional velocity model and regional data exchange will yield accurate location determinations of future seismic events in the Eastern Mediterranean Region.


A review of the earthquake data bank in western Mediterranean countries

(Algeria, Morocco, Tunisia)

 

 

Djillali Benouar

Built Environment Research Laboratory

USTHB, Civil Engineering Institute

Bab Ezzouar, Alger,  Algeria

 

 

The main purposes of this work are: (1) to establish a uniform catalogue of all earthquakes reported in the Maghreb region that satisfies the conditions of homogeneity, (2) to derive from this basic data set the general laws governing the space and time distribution of earthquake occurrences in the seismic source zones, and (3) to evaluate the seismic hazard.

 

For the Maghreb region, earthquake hazards constitute a constant threat to human life and property, sometimes causing major economic losses and disruption. The rapid urbanization, development of critical engineering works such as dams, nuclear power plants, industrialization of cities with modern types of buildings, and the concentration of populations living or settling in hazardous areas are matters of growing concern, as they contribute to heavier loss of life and increase considerably the cost of disaster damage. The environmental concerns and an increased official and public awareness of earthquake hazards have, in the last decade, led to a rapid rise of interest in seismicity and, seismic hazard and risk evaluations in the Maghreb countries.

 

In order to assess the seismic hazard with a degree of reliability, an earthquake data bank of the region under survey that is as complete, homogeneous and accurate as possible is needed. For this purpose, and from the point of view of long-term prediction and seismic hazard assessment, it is imperative that input data in the catalogues of the Maghreb countries be revised and homogenized.

 


Towards a macroseismic survey team for severe earthquakes in Europe and the Mediterranean Basin

 

 

Roger Musson

British Geological Survey, Edinburgh, UK

 

 Ina Cecic

Geophysical Survey of Slovenia, Ljubljana, Slovenia

 

 Dieter Mayer-Rosa

Zurich, Switzerland

 

 

Increased interest in seismic hazard and risk in recent decades has greatly increased the importance of macroseismic data. However, strong seismic events in Turkey and Greece in 1999, as well as numerous examples from the past, have shown that the seismological community in Europe lacks any mechanism for the fast organisation of macroseismic data collection in the case of damaging earthquakes in European territory. There now exists a proposal for the establishment of a framework, under the aegis of the European Community and European Seismological Commission (ESC), for sending survey teams to the area affected by strong earthquakes in Europe and adjacent areas, to ensure that in future these important data are recorded and made available to the wider community. This would be administered by the ESC, on behalf of the EC, to ensure that the interests of the wider community are served by the preservation and promulgation of the data sets recording the effects of such earthquakes. This framework would incorporate a field investigation team formed of seismologists with experience in collecting and evaluating macroseismic data, who would travel to the affected area as soon as possible after the earthquake and there organise the survey in order to collect high-quality intensity data. The team would be organised within the ESC and report to the EC. The name Field Investigation Team of the European Seismological Commission (FITESC) has been proposed. The formation of such a team was endorsed by a resolution passed at the XXVII General Assembly of the ESC at Lisbon in September 2000, and a provisional committee was appointed to investigate the practical aspects. The operation of the field investigation team would not be expensive, but would need special long-term financial support outside of existing project initiatives. Such sources of funding are being investigated, but equally it is important to consider at the outset the questions about the organisation and personnel, and how the best procedures will be adopted.

 


The role of the Egyptian National Seismological Network in better understanding of the seismicity in Egypt and surrounding countries

 

Salah El-Hadidy

National Research Institute of Astronomy and Geophysics(NRIAG)

Helwan, Egypt

 

 

Real-time seismic monitoring systems enhance emergency response and, in some cases, short-term mitigation and preparedness.  At present, many earthquake-prone nations are beginning to develop and use rapidly emerging technology of real-time seismic monitoring and warning systems.  The main function of the real-time seismic monitoring system is to provide information on the location, magnitude, frequency of occurrence, and duration. The occurrence of Dahshour earthquake on 12 October 1992, with Mb=5.8 and an epicentral distance about 35 km southwest of Cairo, prompted the establishment of the Egyptian National Seismic Network (ENSN).  This network was planned to  be a technologically sophisticated system and fundamentally adequate to meet important needs for public safety and emergency management, quantification of hazards associated with both natural and man-made events, and engineering applications.

 

The first step toward establishing a new seismic network is understanding and setting the network goals.  For a better understanding of the seismicity, a denser seismic network is required to locate the hypocenter with good accuracy and to examine the fault plane solution. Subsoil conditions such as the stratigraphy, distribution, and dynamic behavior of the sediments should be studied in detail.  Strong motion seismographs are necessary to obtain accurate ground motion.  Regional cooperation is very important for getting more accurate location for epicenters.

 

Deep seismic sounding experiments have been carried out in Egypt since 1972. Many seismic profiles have been carried out in the eastern Desert and northern Egypt. The velocity model of northern Egpyt was constructed using surface wave dispersion through three different propagation paths. 3-D seismic tomography was performed in the area of the Dahshour earthquake (Cairo earthquake).   

 


Model inaccuracy and bias in hypocenter estimation

 

Gideon Leonard, Israel Atomic Energy Commission

David M. Steinberg, Tel Aviv University

Micha Bodor, Tel Aviv University

Yair Bartal, Israel National Data Center

Yochai Ben Horin, Israel National Data Center

 

 

The International Monitoring System (IMS) must meet the difficult challenge of monitoring global seismic activity with a sparse network to verify compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT).  The goals of the seismic monitoring of the CTBT are ambitious:  to detect, time and locate seismic events, and to screen out events that are clearly natural phenomena.   Yet the means to accomplish these goals are limited.  The IMS seismic network must cover the entire globe with a small, sparse set of arrays and stations. 

 

Good location estimates are crucial to the success of the seismic monitoring.   The CTBTO requires both high precision location estimates (i.e. small error regions) and accurate estimates (i.e. no systematic biases that move the error  ellipses away from the true epicenters).  The quality of the Prototype IDC (PIDC) location estimates was examined by Bondar (1997, 1998).  Bondar (1998) concluded that “the ellipse coverage still does not meet the 90% theoretical coverage value, nor the 1000 km2 on-site inspection requirement.” 

 

We suggest that the most important reason for the failure of the PIDC error regions is the effect of modeling errors on the locations.  We present a theoretical framework, based on the work of Pavlis (1986) for representing both systematic and statistical errors in event location.  The theory provides an equation that can be used to accurately predict systematic location bias from the modeling errors.  Then we explore in more detail, via a simulation study, the question of potential IDC location errors for seismic events in Israel.  We consider both systematic location bias due to inaccuracies in the travel time model and statistical variation due to errors in picking phase onsets.  We find that systematic epicentral bias might be as large as 30 km, despite a relatively good station configuration, in which case it will dominate the statistical errors.

 

Our simulation is based on a set of possible scenarios for model inaccuracies.  There is, to date, insufficient data to assess whether these scenarios are realistic.  Results from the Dead Sea explosions indicate a possible velocity gradient in effect at short distances for wave paths that cross the Dead Sea Transform.  Of more interest, though, for IDC locations of events in Israel, is the accuracy of the IASPEI91 travel time model at regional distances.  At these distances the data from the Dead Sea explosions are quite limited due to the failure to pick up clear signals in Europe and the total lack of phase arrivals to the east of Israel.  Thus we conclude that more research is needed to determine whether the actual bias for locations in Israel might be as serious as we found in our simulation study.


Seismic hazard assessment: Simultaneous effect of earthquakes at close and distant sites

 

G. Leonard, Israel Atomic Energy Commission

D.M. Steinberg, Department of Statistics and Operations Research, Tel-Aviv University, Israel

 

 

The damage from a major earthquake may be spread out over a broad region.  Decision makers who plan rescue and relief efforts necessarily focus attention on sites closest to the epicenter.  But they also must consider what will be the effects of the earthquake at more distant sites.  This information can be of great value in planning the geographic distribution of equipment, personnel and critical relief facilities such as hospitals, bridges, etc.  Our objective in this work is to present a method for carrying out joint hazard analysis at multiple sites that will provide a basis for preparedness planners.  Our approach integrates ideas from probabilistic and deterministic hazard analyses to establish a basis for evaluating the seismic hazard due to a potential large earthquake.  A unique feature of the method is the specific attention to multiple sites, by contrast with the single-site emphasis in probabilistic hazard analysis.  We do this by exploiting the fact that empirical relationships relating the peak ground acceleration at a site in question to the magnitude of an event and to the source-to-site distance include two sources of variation.  One source is specific to the event, and so common to all data from that event.  The second source is specific to each particular observation.  This feature enables us to carry out a probabilistic hazard analysis at a far site conditional on a given level of peak ground acceleration at a near site.  We illustrate our ideas by applying the method to Israel.

 


Seismic hazard assessment in Spain: New developments in Catalonia

 

X. Goula

Geological Survey, Institut Cartogràfic de Catalunya (ICC)

 

 

The current Spanish seismic code (NCSE -95) was published in 1995. This code includes a probabilistic seismic hazard map based on former hazard studies. Recently, a few studies have been carried out to review this map considering some updated seismic catalogues.

 

For the region of Catalonia, after a thorough revision of geological and seismic data, a new seismic hazard map is proposed that combines the probabilistic and deterministic models and integrates uncertainties resulting from sensitivity analysis. This map is complemented with soil-effect studies carried out at regional and local scales.

 


A Critical Examination of Near-Field Accelerograms from the

Sea of Marmara Region Earthquakes

 

Polat Gülkan

Disaster Management Research Center and

Department of Civil Engineering

Middle East Technical University

Ankara 06700, Turkey

 

 

In 1999, Turkey was struck by two major earthquakes that occurred 86 days apart on the North Anatolian fault system. Both of these earthquakes had right-lateral strike slip mechanisms with moment magnitudes greater than 7. The number of strong motion records obtained from the Kocaeli earthquake (17 August 1999, Mw = 7.4) was 34. The second event, designated as the Bolu-Düzce earthquake (12 November 1999, Mw = 7.2), triggered 20 instruments. Among the records that we have from these earthquakes, seven are near-source ground motion data. These records were obtained from the cities of Gebze, Yarimca, Izmit (capital city of the province of Kocaeli), Adapazari (capital of the province of Sakarya), Düzce (shaken strongly in both events) and Bolu.  In many of these urban centers extensive structural damage was observed.  While these near field data have greatly expanded the strike-slip near-source ground motion data base world wide for Mw>7 they represent a blurred image of the actual severity of the ground motions in the epicentral area.  Regrettably, sparseness of the national strong motion network, and the unrepresentative geologic conditions at the recording sites contributed to this deficiency. After decomposing the acceleration traces into fault-normal and fault-parallel components, I analyze the records with earthquake-resistant structural engineering criteria in mind. There appears to be no uniform support for the judgment that fault-normal direction should represent a greater damage causing potential when this potential is based on ground story drift ratio spectra.  The component with the larger ground velocity correlates better with the component with the larger drift demand.

 

 


Attenuation modeling of  recent earthquakes in Turkey 

Polat Gülkan

Disaster Management Research Center

Middle East Technical University

Ankara, Turkey

 

 

This presentation deals with the derivation of a consistent set of empirical attenuation relationships for predicting free-field horizontal components of peak ground acceleration (PGA) and 5 percent damped pseudo acceleration response spectra (PSA) from strong ground motion records recorded in Turkey. The relationships were derived for Turkey from attenuation relationships previously developed by Boore et al. (1997) for shallow earthquakes in western North America. The used database was compiled for earthquakes in Turkey with moment magnitudes (MW)  >5 that occurred between 1976-1999, and consisted of horizontal peak ground acceleration and 5 percent damped response spectra of accelerograms recorded on four different site conditions classified as hard rock, rock, soil and soft soil. The empirical equations for predicting strong ground motion were typically fit to the strong motion data set by applying nonlinear regression analysis according to both random horizontal components and maximum horizontal components. Comparisons of the results to other attenuation equations shows that ground motion relations or time series for earthquakes in one region cannot be simply modified for use in engineering analyses in another region.  Our results appear to underestimate the Boore et al. curves.

 

 


Seismic hazard assessment in northern Algeria

Part I: Area and site–specific seismic hazard

 

M. Hamdache1, J. K. Lapajne2 and B. Sket Motnikar2

 

1Departement Etudes et Surveillance Sismique, Centre de Recherche en Astronomie, Astrophysique et Geophysique (CRAAG). BP 63 Bouzareah, 16340 Algiers, Algeria

2Department of Seismology, Environmental Agency of the Republic Slovenia, Dunajska 47/VIII, SI-1000, Ljubljana, Slovenia

 

 

A seismogenic zone model is proposed in northern Algeria based on all the available seismotectonic data in north Algeria.  The procedure developed by Kijko and Sellevoll (1989, 1992) and Kijko and Graham (1998, 1999) is used to estimate seismic hazard parameters in each seismogenic zones.

 

The area-specific seismic hazard parameters obtained (b-value, mean annual activity rate l(M) above a threshold M, and the maximum possible magnitude Mmax), have been used to derive site-specific seismic hazard parameters in terms of the maximum possible PGA at a hypothetical engineering structure and in terms of 50 years of probability of exceedence and to derive the seismic hazard map in northern Algeria, in terms of maximum PGA with a 10 % excceedence during a time period of 50 years, especially by using the spatially smoothed seismicity approach (Lapajne, 2000, Sket Motnikar et al, 2000) and the one developed by Bender and Perkins (1987).


 

 

Evaluation of seismic vulnerability of dwelling buildings in Catalonia, Spain

 

A. Roca

Geological Survey, Institut Cartogràfic de Catalunya (ICC)

 

 

A method for preliminary evaluation of seismic vulnerability of dwelling buildings was developed and applied to the area of Catalonia in order to evaluate earthquake risk for emergency plans. This method, which is based on the European Macroseismic Scale (EMS-98) and a few parameters easily available in the building census, can also be used to generate damage scenarios for a given earthquake. This procedure is being implemented in conjunction with the new broadband VSAT real time seismological network of the ICC to provide Civil Defence centres with fast estimation of effects just after an event is detected and located by the network.

 


Hazard assessment practice in Italy

 

Dario Slejko

Istituto Nazionale di Oceanografia e di Geofisica Sperimentale

Trieste, Italy

 

The present Italian seismic zonation was introduced between 1980 and 1984 and it was based on hazard results obtained in the late Seventies (Gruppo di Lavoro Scuotibilità, 1979). More recently, the Italian Department of Civil Protection financed the National Council for Researches (CNR) for developing new seismic hazard maps intended to be the basis for the revision of the seismic zonation. That project consisted in the preparation of an earthquake catalogue (Camassi and Stucchi, 1996), in the definition of a seismotectonic model for the Italian territory (Meletti et al., 2000), and in the computation of the hazard maps (Slejko et al., 1998). The hazard maps represent the expect ground shaking with a 475-year return period in terms of peak ground acceleration (PGA) and macroseismic intensity. On the basis of those and similar results obtained by other institutions, a proposal of revision of the present seismic zonation was formulated (Gruppo di Lavoro, 1999).

To unify the existing hazard results at national level, new maps were produced a few years later (Albarello et al., 2000). The differences between these new maps and the CNR's previous ones consist in the use of an updated earthquake catalogue, of a new completeness approach which leads to weighted seismicity rates computed over the whole catalogue span, and of the elimination of the background zones. Hard boundaries were used for all the seismogenic zones without introducing for them the maximum magnitude. Two PGA attenuation relations (Sabetta and Pugliese, 1987; Ambraseys et al., 1996) weighted 50% each and a third specific one for the Etna volcanic zone; revised intensity attenuation relations (Peruzza, 2000) were considered as well. The influence of some of those parameters on the hazard results was explored (Rebez and Slejko, 2000).

On the basis of the same setting up which was used for the national hazard maps, further hazard results were obtained in terms of spectral values (Rebez et al., 1999) or devoted to analyse the deficiencies of the present seismic zonation for central Italy (Peruzza et al., 2000), where a recent earthquake occurred. Moreover, attention was paid to improve the modelling of the seismic process with time-dependent approaches (Peruzza, 1999) and to introduce the site response in the regional hazard estimates. Considering this last point, a project for seismic risk assessment in the Friuli - Venezia Giulia region (NE Italy) has been undertaken and one of its main task consists in the preparation of the regional hazard map which considers also a simplified soil characterisation (Peruzza et al., 2001).

 

References

 

Albarello D., Bosi V., Bramerini F., Lucantoni A., Naso G., Peruzza L., Rebez A., Sabetta F. e Slejko D; 2000: Carte di pericolosità sismica del territorio nazionale. Quaderni di Geofisica, n. 12, Editrice Compositori, Bologna, 7 pp.

Ambraseys N. N., Simpson K. A. and Bommer J. J.; 1996: Prediction of horizontal response spectra in Europe. Earth. Eng. Struct. Dyn., 25, 371 - 400.

Camassi R. and Stucchi M.; 1996: NT4.1, un catalogo parametrico di terremoti di area italiana al di sopra della soglia del danno. C.N.R. GNDT, Milano, 86 pp.

Gruppo di Lavoro; 1999: Proposta di riclassificazione sismica del territorio nazionale. Ingegneria Sismica, 14/1, 5 - 14.

Gruppo di Lavoro Scuotibilità; 1979: Carte preliminari di scuotibilita' del territorio nazionale. C.N.R. P.F. Geodinamica pubbl. 227, ESA, Roma, 25 pp.

Meletti C., Patacca E., Scandone P., 2000. Construction of a seismotectonic model: the case of Italy. Pure Appl. Geophys., 157, 11-35.

Peruzza L. (a cura di); 1999: Metodi innovativi per la stima dell'hazard (MISHA) - Applicazione all'Italia centrale. CNR-GNDT, Roma, 176 pp.

Peruzza L., Rebez A. and Slejko D.; 2001: Seismic hazard mapping for administrative purposes. Natural Hazards, 23, 431-442.

Peruzza L., Rebez A., Slejko D. and Bragato P.L.; 2000: The Umbria - Marche case: some suggestions for the Italian seismic zonation. Soil Dynamics and Earthquake Engineering, 20, 361-371.

Rebez A., Peruzza L. and Slejko D.; 1999: Spectral probabilistic seismic hazard assessment for Italy. Boll. Geof. Teor. Appl., 40, 31 - 51.

Rebez A. and Slejko D.; 2000: Sensitivity analysis on the input parameters in probabilistic seismic hazard assessment. Soil Dynamics and Earthquake Engineering, 20, 341-351.

Peruzza L.; 2000: Macroseismic attenuation relationships of Italian earthquakes for seismic hazard assessment purposes. Boll. Geof. Teor. Appl., 41, 31-48.

Sabetta, F. and Pugliese, A.: 1987, Attenuation of peak horizontal acceleration and velocity from Italian strong-motion records, Bull. Seism. Soc. Am. 77, 1491-1513.

Slejko D., Peruzza L. and Rebez A.; 1998: Seismic hazard maps of Italy. Annali di Geofisica, 41, 183 - 214.

 


Recent developments in Iranian seismic hazard studies

 

Mehdi ZARÉ

International Institute of Earthquake Engineering and Seismology

P.O.Box: 19395/3913

Tehran, IRAN

 

Introduction

The recent studies of seismic hazards in Iran are discussed in this presentation. The seismic zoning studies in Iran are performed for hazard assessment purposes for the engineering construction, urban plans and in the research projects. The hazard assessments for dam and power plant sites are established as the routine studies along with other disciplines (Geology, Hydrology, Geotechnical and Structural Engineering studies, etc…). However such type of considerations are not yet performed for all of mining sites and lifeline facilities. The recent researches are concentrated on the seismotectonic modeling, strong motion data studies, attenuation law, seismic zoning maps and the application of neural networks in hazard assessments. This presentation is concentrated on the recent developments in seismic hazard studies and the trends that are expected for the future researches in Iran.

     

Framework of the Presentation:

The disciplines which are discussed in this presentation are: The seismotectonic modeling for different regions of Iran, determination of seismogenic layer for the Iranian crust, and the seismic source zones. The recent efforts on seismic hazard studies in Iran are principally concentrated on the determination of the seismogenic layer and the depth of the upper crust for different places of Iran. The seismotectonic zoning is performed in Iran using the recent seismic data recorded by the local networks of the country, as well as neotectonic (Figure-1) and paleoseismology studies.

 

Determination of active fault zones for different urban areas in Iran. These studies were conducted, for instance, for the North Tehran (Figure-2) and Tabriz faults.

 

The attenuation law was developed using the Iranian strong motion data (actually more than 1500 stations are installed in the national network and more than 3000 records are available). The coefficients are found for the attenuation law for the peak and spectral values (Figure-3). The site condition for the accelerograph stations are determined using the receiver function method (estimating the H/V spectral amplification ratios).   

 

Seismic hazard zoning in the large scales (regional purposes) and for the urban and industrial localities.

 

The Trend of the Further Studies:

The future trends of the seismic hazard and zoning studies in Iran are: To develop the coulomb stress change maps for the active fault zones in Iran; determine the active fault zones in the urban areas; continue studies to develop the coefficients of attenuation laws using the recent strong motion data in Iran, and finally; the seismic zoning maps using the spectral values for different periods and site conditions.  

 

References:

-          Zaré M., 1999, Contribution a l’études des mouvements forts en Iran ; du Catalogue aux lois d’atténuation, PhD thesis, Université Joseph Fourier, 237p.

-          Zaré M. 2001,  Structural collision zones along the Gowk Kuhbanan Fault Systems the Kerman Area (SE Iran), Research Letters of Seismology and Earthquake Engineering (Pajooheshnameh), in Persian, Vol.3, No.4, PP.22-33.


-          


Figure-1: The neotectonic map of the Kerman region in SE of Iran (western parts of the Lut Desert) (Zaré 2001).


 

 


Figure-2: North Tehran Fault zone is shown between two flashes.


Figure-3: Response spectral acceleration using the attenuation of acceleration spectral values for Iran, is compared with some of similar relationships for Europe (Ambraseys, 1995), Italy (Calliot, 1994) and USA (Joyner and Boore 1988) [in Zaré 1999].


 


Urban Development and Construction Along the North Tabriz Fault Zone in NW Iran: A Field Visit Report

 

Mehdi ZARÉ

International Institute of Earthquake Engineering and Seismology

P.O.Box: 19395/3913

Tehran, IRAN

 

The construction in the north Tabriz fault zone and the urban developments are discussed in this presentation, based on a recent visit to the area (May 2001). The North Tabriz fault zone, with a compressional and right-lateral strike slip movement, is one of the most active Iranian faults.  It has reactivated 16 times during historical time (12 times with the complete destruction of the city of Tabriz). The last reactivation of this fault was during the great earthquake of 1780 in Tabriz. Since then, no major event has been reported.  The microseismic and moderate activity of this fault is monitored by a local network. The magnitude-fault length empirical relationships and the intensity-magnitude correlations indicate that this fault has ruptured several times in its history by magnitudes greater than 7.0. The urban development of the city of Tabriz towards the north resulted in the construction of tall building (up to 14 stories) in the fault zone. The unsuitable site conditions are intensified by a landslide risk because of the marley-clayey Cenozoic deposits along and nearby the fault zone. A new district in which the geohazard is estimated to be the highest is “Baghmisheh” NE of Tabriz. Such conditions could be seen more or less, in a larger scale, in North Tehran area. The earthquake hazard could be multiplied by the possibility of: 1) the direct fault rupture; 2) the directivity effects, in which the tall building could be affected the most, and; 3) land slides, to be induced by the fault reactivation. Such effects along with a tectonic description of the northwest Iran tectonic and seismotectonic conditions are discussed in this presentation by showing 30 recent slides related to different aspects discussed in this abstract. 

 

 

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