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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
United Nations Educational, Scientific and Cultural
Organization
Paris, France
Contact:
Dr. Soren T. Malling
Telephone:
33 1 45 68 41 22
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.
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
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.
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.
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
·
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
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
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
·
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
·
166-page workbook
·
CD-ROM containing spreadsheets and all workbook information and data (in
the pocket on the back cover of this report)
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.
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
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
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
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
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
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
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
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
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
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
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
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
Jeannette Fernandez
Facultad de Ingenieria Civil
Escuela Politecnica Nacional
Quito, Ecuador
Tel. 593
2 563 077
Fax 593
2 567 847
Michael P. Foose
U.S. Geological Survey
917 National Center
Reston VA 20192, USA
Tel. 1
703 648 6055
Fax 1
703 648 4227
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
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
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
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
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
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
Khaled Kahhaleh
Building Research Center
Royal Scientific Society
Amman, Jordan
Tel. 962
6 534 4701/ext.750
Fax 962
6 534 7399
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
Gideon Leonard
Israeli Atomic Energy Commission
PO Box 7061
Tel Aviv, Israel
Tel. 972
3 646 2955
Fax 972
3 646 2539
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
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
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
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
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
Artie Rodgers
Lawrence Livermore National Laboratory
Livermore
CA 94550, USA
Tel. 1
925 423 5018
Fax 1
925 423 4077
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
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
Frederick O. Simon
11813 Stuart Mill Road
Oakton, VA 22124-1227, USA
Tel. 1
703 620 2772
Fax 1
703 620 2772
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
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
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
Torild Van Eck
ORFEUS c/o Seismology Division
Royal Netherlands Meteorological Institute
3730 AE De Bilt, The Netherlands
Tel.
Fax 31
30 2201 364
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
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
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
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.
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
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
National Research Institute
of Astronomy and Geophysics(NRIAG)
Helwan, Egypt
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
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.
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
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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