Earthquake early warning: Adding societal value to regional networks and station clusters Richard Allen, UC Berkeley Seismological Laboratory [email protected]
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Earthquake early warning:Adding societal value to regional
networks and station clusters
Richard Allen, UC BerkeleySeismological Laboratory
Sustaining funding for regional seismic networks is hard
– exciting scientific questions can motivate a new network
Earthquake early warning is one such capability/product
– long-term sustained funding requires broader societal buy-in
capabilities/products that are valued by society
capabilities/products that are updated/available regularly
Key points
Recent scientific advances and technological developments now makeearthquake early warning possible
Early warning systems are being developed and implemented around theworld
Active systems: Japan, Taiwan, Turkey, Mexico, Romania
Test system in CA accurately predicted the ground shaking in San Franciscobefore it was felt for the Alum Rock earthquake
Warning systems could provide additional societal value to any seismicnetwork in earthquake prone regions
Simple “in town” station clusters could provide a few seconds warning
Regional network systems could provide tens of seconds warning
High earthquake fatality rates occur due to poor/rudimentary construction
Many of these buildings are single story
Only takes a few seconds to get out
What is early warning?
1. Rapid detection of an earthquake in progress 2. Rapid notification of observed ground shaking 3. Prediction and notification of future ground shaking
Goal: to provide warning prior to damaging ground shaking
Current realtimeearthquake information:
Post earthquake
“ShakeMap”
Map of observed groundshaking available 7-10minutes after an event
What is early warning?
1. Rapid detection of an earthquake in progress 2. Rapid notification of observed ground shaking 3. Prediction and notification of future ground shaking
Goal: to provide warning prior to damaging ground shaking
AlertMap0 sec
AlertMap+2 sec
ShakeMap+ minutes
Continuum of earthquake information:1. Detection 2. Rapid magnitude,
ground shakingprediction
3. Post earthquakeinformation
ElarmS-RT
Real-time implementationof ElarmS in California
OperationalOctober 10th, 2007
P-wave methodology:using first arrivingenergy to maximizewarning time
ElarmS-RT
Alum Rockearthquake8:04pm Tue Oct 30th, 2007Mw 5.4
ElarmS-RT AlertMap
ElarmS AlertMap
Alum Rock earthquakeOctober 30, 2007
Mw 5.4
detection 20:04:59
ElarmS-RT AlertMap
CISN ShakeMap
Alum Rock earthquakeOctober 30, 2007
Mw 5.4
ElarmS AlertMap
detection +1 sec Mag: 5.2 ΔMMI: 0.1 ± 0.6
ElarmS-RT AlertMap
CISN ShakeMap
Alum Rock earthquakeOctober 30, 2007
Mw 5.4
ElarmS AlertMap
detection +2 sec Mag: 5.8 ΔMMI: -0.1 ± 0.5
ElarmS-RT AlertMap
CISN ShakeMap
Alum Rock earthquakeOctober 30, 2007
Mw 5.4
ElarmS AlertMap
detection +3 sec Mag: 5.9 ΔMMI: 0.1 ± 0.6
ElarmS-RT Performance – Alum Rock earthquake
origintime
San Joseshakes Oakland
shakes
0 +5 +10 +15 +20 sec
San Franciscoshakes
epicenterSan Jose
OaklandSan Francisco
ElarmS-RT Performance – Alum Rock earthquake
origintime
San Joseshakes Oakland
shakes
0 +5 +10 +15 +20 sec
San Franciscoshakes
P-wave reachesseismometers
ElarmS-RTdetection
1st AlertMap2nd 3rd
15 sec telemetry delay
ElarmS-RT Performance – Alum Rock earthquake
origintime
San Joseshakes Oakland
shakes
0 +5 +10 +15 +20 sec
San Franciscoshakes
ElarmS-RTdetection
1st AlertMap2nd 3rd
15 sec telemetry delay
+150
1st
AlertMaps2nd 3rd
+5 +10 +20 sec
10+ secwarning
ElarmS-RTdetection
Oaklandshakes
San Franciscoshakes
Potential
15 sec telemetry delay
Potential 1 sec ?
Warning timesfor San Francisco
• Existing stations
• Telemetry upgrade
• From “Alarm” time (4 sec of data at 4 stations)
Range of warningtimes: 0 to 1 min
Warning times
• 20 sec warningfor San Franciscoand Oakland
Loma Prietaearthquake
• 10 sec warningfor San Franciscoand Oakland
Alum Rockearthquake
at the Moscone Center
Range of warningtimes: 0 to 1 min
Loma Prieta
ABAG ground shaking
Oakland 66% fatalities
San Francisco 18% fatalities
Cypress viaduct collapse
Falling masonry
Apartmentbuilding collapse
84% of the fatalities were atdistances which could have
received 20 sec warning
Earthquake early warning
JapanTaiwan
Mexico
Turkey
Romania
Italy
Greece
India
UnitedStates
Operational systemsSystems under developmentaround the world
around the worldCurrent applications of early warning
Istanbul
• Electric power plant
• High rise building (bank)
Taiwan
• Rail system
• Hospital
Mexico and Oaxaca Cities users
• Private industry 28• Schools 84• Housing complex 1• TV/Radio stations 34• Government offices 94• Subway 4
Japan
• Rail/Metro systems
• Fire/rescue organizations
• In home information;door/window opening;utility shut-off
• Elevator control
• Outdoor works
• Factories
• Power plants
• Hospitals
GSHAP
S-wave
P-wave
Warning system designsLocation of seismic network: End-member 1: in the earthquake source region
fault
SeismicStations
S-wave
P-wave
Warning system designs
fault
SeismicStations
Location of seismic network: End-member 1: in the earthquake source region
S-wave
P-wave
Warning system designs
fault
SeismicStations
Warning time is proportional to thedistance from the sensor to town
50 km ~10 sec warning100 km ~30 sec warning200 km ~50 sec warning
Location of seismic network: End-member 1: in the earthquake source region
Mexico City: Seismic Alert System
• Developed in 1989 in thewake of the 1985Michoacan earthquake
• 15 stations along coast
• Station data transmittedto central processing inMexico City
• Warning issued whentwo stations indicate anevent greater thanmagnitude 5
• ~300 km allows 60+ secwarning
300 km
“Front detection”
Guerrero earthquakeSeptember 14, 1995
• magnitude 7.3
• event successfullydetected and analert issued
• 72 sec warning
• no real damage inMexico City
S-wave
P-wave
Warning system designs
SeismicStations
Location of seismic network: End-member 1: in the earthquake source region End-member 2: in town
Why 4-5 stations?
Testing in California showsthat waiting for 4-5 stationdetections prevents almostall false alarms
S-wave
P-wave
Warning system designs
SeismicStations
Location of seismic network: End-member 1: in the earthquake source region End-member 2: in town
Warning time is dependent on theP-to-S time
50 km 2-3 sec warning100 km ~8 sec warning200 km ~18 sec warning
S-wave
P-wave
Warning system designs
fault
SeismicStations
Location of seismic network: End-member 1: in the earthquake source region End-member 2: in town Hybrid: around town
S-wave
P-wave
Warning system designs
fault
SeismicStations
Location of seismic network: End-member 1: in the earthquake source region End-member 2: in town Hybrid: around town
S-wave
P-wave
Warning system designs
fault
SeismicStations
Location of seismic network: End-member 1: in the earthquake source region End-member 2: in town Hybrid: around town
S-wave
P-wave
Warning system designs
fault
SeismicStations
Location of seismic network: End-member 1: in the earthquake source region End-member 2: in town Hybrid: around town
Pakistan 2005
Islamabad
Muzaffarabad
Uri
M 7.6
80,000 fatalities– poor construction– many single story buildings
Pakistan 2005
Muzaffarabad: Regional capitol20 km from epicenter50% buildings destroyed
Warning time: P-to-S: ~3 secS-arrival: 6.5 sec best case 1-2 sec warning
Pakistan 2005
Uri: 60 km from epicenter80% of buildings destroyed
Warning time: P-to-S: 7.5 sec ~4 sec warningS-arrival: 18 sec 10+ sec warning
Pakistan 2005
Islamabad : 105 km from epicenter Warning time: P-to-S: 12 sec 8 sec warning
S-arrival: 28 sec 20+ sec warning
Bam
M 6.6
Iran 2003
Bam: 12 km from epicenter Warning time: P-to-S: 1.5 sec
S-arrival: 4 sec no warning
Peru 2007
Pisco: 68,000 people80% buildings destroyed50 km from epicenter
Warning time: P-to-S: 6 sec 3 sec warningS-arrival: 15 sec 10 sec warning
M 8.0
Pisco
Peru 2007
Ica: 120,000 people50% buildings destroyed115 km from epicenter
Warning time: P-to-S: 16 sec 10 sec warningS-arrival: 35 sec 30 sec warning
M 8.0
Ica
Warning time
• Few seconds for “in town”station clusters
• Tens of seconds for regionalnetworks
High impact
• Poor/rudimentaryconstruction results inhigh fatality rates
• Evacuation possible in afew seconds
Summary
• There is rapid development and implementationof early warning around the world
• Adding a warning capability to seismic networksadds societal value
ElarmS workshop
More information at…
UC Berkeley
May 5-16, 2008
Week 1: Lectures and exercises to familiarize participantswith the methodology and code
Week 2: Assist participants to get the code running back intheir home institutions
Participants need to be self-supporting
Contact: [email protected]
Different approaches for different timescalesMitigating seismic hazard
Decades: Probabilistic seismic shaking hazard
building codes and land use regulation
Few years: Hazard information and education
individual and community awareness and preparedness
Months to hours: Prediction of the time and location of an earthquake
Not possible in the foreseeable future
Seconds to minutes: Earthquake warning systems
Rapid detection of earthquake, prediction and warning of shaking
Months to hours: Prediction of the time and location of an earthquake
Not possible in the foreseeable future
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