An International Workshop on the Utilization of Seismographic Networks within
the Global Earth Observing System of Systems
Tuesday, August 23, 2005
Products Session
Scribe: Charles R. Hutt
Moderator: Avi Shapira
Note: The scribe’s notes below are followed by a combined moderator-scribe summary.
1st Talk: Paul Earle – Overview of Seismological Products in a GEOSS Perspective
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Rapid production of maps of ground shaking intensity (theoretical) – have
capability on global scale.
Earthquake early warning
Rapid assessment of earthquake impact
o Extremum
o QuakeLoss
o Global disaster alert system
o PAGER
 Est. of no. of people exposed
o GEOSS – could help by providing access to and development of diverse
high-quality data sets (SM, satellite, GPS, population, infrastructure
vulnerability)
o Global Intensity Reports (Did you feel it? Internet postings)
Earthquake alerts
Remembering and learning from what happened
o Keeping records (bulletins, etc)
Reducing Risk
Global Seismic Hazard Map
o Local seismic hazard maps to finer scale (e.g., US)
Studies of earthquake effects
o Scenarios, response plans
Research is the key to improving and providing benefits to society
Tsunami warning, volcano monitoring, nuclear test monitoring
GEOSS can help by providing coordination
2nd Talk: Remy Bossu (EMSC) – The European-Mediterranean Experience in
Monitoring System of Systems and Integrated Products
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Complementary Euro/Euro-Med organizations: EMSC & ORFEUS
o Both are non-profit
A system of systems for real-time information
o Only parametric data
o Authoritativeness is considered
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o Both automatic and manual systems are used
Coordinate with national seismic services
o Redundancy (backup), border regions, etc.
RT EQ info: Dynamic web page updated every minute
o Automatic determination of felt area
Euro-Med Bulletin
Inventory of accelerometer data (~3000 sensors in Europe & Mid-East)
Improving cooperation
Long experience in international cooperation
Integration of existing infrastructures is cost-efficient, ensures whole community
participation
3rd Talk: Stuart Weinstein (NOAA/PTWC) – The Use of International Seismic
Networks for Tsunami Warnings
1st Presentation: Indian Ocean developments:
 Existing warning centers all in Pacific: PTWC, ATWC, & Japan
 Indian Ocean: Being organized by IOC (? Check slides)
o Study tours, training
o Upgrading/expanding sea level network in Indian Ocean
2nd Presentation: The Use of International Seismic Networks for Tsunami Warnings
 GSN stations mostly used for tsunami warnings (near real time)
 Investigating Mwp (P-wave magnitude) and mantle wave magnitude methods for
fast automatic determination of magnitudes
 Get data via USGS Earthworm system
 Issue time of PTWC bulletins for teleseisms: 1994: about 1 hour. Now: about 15
minutes
 Issue time for local quakes: down to about 3 minutes now
 Main points:
o Great global network density
o Leverage of assets (OBS, Hydrophone arrays)
o Communications
o Success to STS-1 very important
4th Talk: Brian Tucker (Geohazards International) – Some Thoughts on the Use of
Seismographic Networks to Promote Global Earthquake Risk Management
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Global EQ Risk
o Percent of global population in urban areas is increasing, especially in
developing countries (next 20 years)
o Population of 20 largest at-risk cities is increasing much faster in
developing countries than in developed countries (but – is EQ resistance
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of buildings same in both? No! Lethality now is much greater because of
increases in population in high-risk urban areas and poor buildings.)
Promoting Global EQ Risk Management
o Increase demand for EQ risk management
o Increase capability of local organizations by:
 Increasing their reputation
 Increasing their resources (technical & human, not just $)
 Increasing their collaboration (less competition)
Specific Suggestions for GEOSS
o Rapid distribution of EQ effects
 Increases understanding of EQ risk
 Increases reputation of local organizations
o Convene workshops about regional EQ risk and risk management
 Increases reputation of and collaboration among local orgs
 Raises awareness of solution, not just problem
5th Talk: Thorne Lay (UCSC) – Large Earthquake Rapid Finite Rupture Model
Products
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Current practice:
o Standard seismic operations (produce magnitudes & locations in standard
ways)
o Further point-source seismic analyses (energy, focal mechanism, seismic
moment, source time function, moment tensor inversion, refined catalog
parameters)
o Point source characterization is insufficient for very large quakes
What we would really like to know:
o Slip vectors over entire area of rupture zone
o How to get this information rapidly?
Next generation information:
o Patterns of ground motion (e.g., Shakemap)
o Stress transfer calculations
o Finite faulting characteristics:
 Rupture length
 Azimuthal rupture duration variations
 Azimuthal shaking variations (directivity)
 Fault slip distribution
Why do we care?
o Value of finite source models:
 ID actual fault plane
 Assess tsunami excitation more confidently
 Predict damage patterns
 Evaluate aftershock/triggering potential
 Quantify tectonic process involved
 Advance understanding of EQ processes
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Rupture finiteness of fault results in predictable waveform variation
o Azimuthal variation of SP signals indicates rupture finiteness
 Array processing (see results from Japan – Hi-Net Array)
 Method forces coherent stacking across array (movie showed
propagation of the rupture northward for Sumatra event)
o Inversion of P waves for slip heterogeneity for 2004 Sumatra (BB data)
 But using only P waves doesn’t give total picture
 Invert everything: complete inversions of body and surface waves
o Do it Quickly! Isolation of Source Time Functions by Deconvolution of
Surface Wave Impulse Response
 Can be done automatically (e.g. 2-D rupture imaging from single
station: KIP)
Conclusions:
o Robust seismological techniques exist to rapidly & routinely determine
finite faulting parameters for large events
o Can recover source time history, get 1D & 2D fault slip models quickly
o Complete body and surface wave inversion can be done routinely
o Finite fault parameters can aid in assessing…. (see Thorne’s last slide)
Discussion:
Christa – How about using SM records in cases where BB sensors saturate?
Avi – Agree!
Simpson – Seismology community is focused on data collection & data distribution.
How can seismology community provide useful products?
Rhett – How can GEOSS get this entire group to actually DO everything that is proposed
under GEOSS?
Rosalind Helz – GEOSS is a useful banner under which workshops can be organized, etc.
Engdahl – Puts in a word about location calibration to get reduce location bias.
Products Session Summary:
Paul Earle – Overview of Seismological Products in a GEOSS Perspective
Remy Bossu (EMSC) – The European-Mediterranean Experience in Monitoring System
of Systems and Integrated Products
Stuart Weinstein (NOAA/PTWC) – The Use of International Seismic Networks for
Tsunami Warnings
Brian Tucker (Geohazards International) – Some Thoughts on the Use of Seismographic
Networks to Promote Global Earthquake Risk Management
Thorne Lay (UCSC) – Large Earthquake Rapid Finite Rupture Model Products
This session emphasized the importance of real time alerts for warning systems
(tsunamis, EQ early warnings, EQ alerts). GSN & FDSN data is important in supporting
real time alerts. Products such as PAGER, global ShakeMaps, etc, can be coordinated
globally by GEOSS. USGS/NEIC (Paul Earle), EMSC (Remy Bossu), and
NOAA/PTWC (Stuart Weinstein) emphasized the importance of rapid exchange of
waveform and parameter information in supporting alerting and warning systems.
Thorne Lay: Rapid determination of source parameters (finite source) are made possible
by the rapid availability of waveform data, allowing accurate characterization of the
source process and better, more rapid determination of the tsunamigenic potential and
ground shaking potential of the source.
Brian Tucker: Risks have increased significantly in recent years, especially in the
developing world. This trend is continuing to grow.
 Specific Suggestions for GEOSS
o Rapid distribution of EQ effects
o Convene workshops about regional EQ risk and risk management
Avi – Main points:
Real time methods for warning systems
Catalogs for keeping track of information
International cooperation