Earthquake early warning: Adding societal value to regional networks and station clusters Richard Allen, UC Berkeley Seismological Laboratory rallen@berkeley.edu
Sustaining funding for regional seismic networks is hard exciting scientific questions can motivate a new network long-term sustained funding requires broader societal buy-in capabilities/products that are valued by society capabilities/products that are updated/available regularly Earthquake early warning is one such capability/product
Key points Recent scientific advances and technological developments now make earthquake early warning possible Early warning systems are being developed and implemented around the world Active systems: Japan, Taiwan, Turkey, Mexico, Romania Test system in CA accurately predicted the ground shaking in San Francisco before it was felt for the Alum Rock earthquake Warning systems could provide additional societal value to any seismic network 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? Goal: to provide warning prior to damaging ground shaking 1. Rapid detection of an earthquake in progress 2. Rapid notification of observed ground shaking 3. Prediction and notification of future ground shaking Current realtime earthquake information: Post earthquake ShakeMap Map of observed ground shaking available 7-10 minutes after an event
What is early warning? Goal: to provide warning prior to damaging ground shaking 1. Rapid detection of an earthquake in progress 2. Rapid notification of observed ground shaking 3. Prediction and notification of future ground shaking Continuum of earthquake information: 1. Detection 2. Rapid magnitude, ground shaking prediction 3. Post earthquake information AlertMap 0 sec AlertMap +2 sec ShakeMap + minutes
ElarmS-RT P-wave methodology: using first arriving energy to maximize warning time Real-time implementation of ElarmS in California Operational October 10 th, 2007
ElarmS-RT Alum Rock earthquake 8:04pm Tue Oct 30 th, 2007 M w 5.4
ElarmS-RT AlertMap Alum Rock earthquake October 30, 2007 M w 5.4 detection 20:04:59 ElarmS AlertMap
ElarmS-RT AlertMap Alum Rock earthquake October 30, 2007 M w 5.4 detection +1 sec Mag: 5.2 ΔMMI: 0.1 ± 0.6 CISN ShakeMap ElarmS AlertMap
ElarmS-RT AlertMap Alum Rock earthquake October 30, 2007 M w 5.4 detection +2 sec Mag: 5.8 ΔMMI: -0.1 ± 0.5 CISN ShakeMap ElarmS AlertMap
ElarmS-RT AlertMap Alum Rock earthquake October 30, 2007 M w 5.4 detection +3 sec Mag: 5.9 ΔMMI: 0.1 ± 0.6 CISN ShakeMap ElarmS AlertMap
ElarmS-RT Performance Alum Rock earthquake origin time San Jose shakes San Francisco shakes Oakland shakes 0 +5 +10 +15 +20 sec San Francisco Oakland epicenter San Jose
ElarmS-RT Performance Alum Rock earthquake origin time San Jose shakes San Francisco shakes Oakland shakes 0 +5 +10 +15 +20 sec P-wave reaches seismometers 15 sec telemetry delay ElarmS-RT detection 1 st 2 nd 3 rd AlertMap
Potential ElarmS-RT Performance Alum Rock earthquake origin time San Jose shakes San Francisco shakes Oakland shakes 0 +5 +10 +15 +20 sec Potential 1 sec? 15 sec telemetry delay ElarmS-RT detection 1 st 2 nd 3 rd AlertMap 0 +5 +10 +15 +20 sec ElarmS-RT detection 1 st 2 nd 3 rd AlertMaps 10+ sec warning San Francisco shakes Oakland shakes
Warning times for San Francisco Range of warning times: 0 to 1 min Existing stations Telemetry upgrade From Alarm time (4 sec of data at 4 stations)
Warning times at the Moscone Center Range of warning times: 0 to 1 min Alum Rock earthquake 10 sec warning for San Francisco and Oakland Loma Prieta earthquake 20 sec warning for San Francisco and Oakland
Loma Prieta Oakland 66% fatalities 84% of the fatalities were at distances which could have received 20 sec warning Cypress viaduct collapse San Francisco 18% fatalities Falling masonry Apartment building collapse ABAG ground shaking
Earthquake early warning around the world Operational systems Systems under development Romania Turkey Taiwan Japan United States Italy Mexico Greece India
Current applications of early warning around the world Mexico and Oaxaca Cities users Private industry 28 Schools 84 Housing complex 1 TV/Radio stations 34 Government offices 94 Subway 4 Taiwan Rail system Hospital Istanbul Electric power plant High rise building (bank) 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
Warning system designs Location of seismic network: End-member 1: in the earthquake source region fault Seismic Stations P-wave S-wave
Warning system designs Location of seismic network: End-member 1: in the earthquake source region fault Seismic Stations P-wave S-wave
Warning system designs Location of seismic network: End-member 1: in the earthquake source region Warning time is proportional to the distance from the sensor to town 50 km ~10 sec warning 100 km ~30 sec warning 200 km ~50 sec warning fault Seismic Stations P-wave S-wave
Mexico City: Seismic Alert System Front detection Developed in 1989 in the wake of the 1985 Michoacan earthquake 15 stations along coast 300 km Station data transmitted to central processing in Mexico City Warning issued when two stations indicate an event greater than magnitude 5 ~300 km allows 60+ sec warning
Guerrero earthquake September 14, 1995 magnitude 7.3 event successfully detected and an alert issued 72 sec warning no real damage in Mexico City
Warning system designs Location of seismic network: End-member 1: in the earthquake source region End-member 2: in town Seismic Stations P-wave S-wave Why 4-5 stations? Testing in California shows that waiting for 4-5 station detections prevents almost all false alarms
Warning system designs Location of seismic network: End-member 1: in the earthquake source region End-member 2: in town Warning time is dependent on the P-to-S time 50 km 2-3 sec warning 100 km ~8 sec warning 200 km ~18 sec warning Seismic Stations P-wave S-wave
Warning system designs Location of seismic network: End-member 1: in the earthquake source region End-member 2: in town Hybrid: around town fault Seismic Stations P-wave S-wave
Warning system designs Location of seismic network: End-member 1: in the earthquake source region End-member 2: in town Hybrid: around town fault Seismic Stations P-wave S-wave
Warning system designs Location of seismic network: End-member 1: in the earthquake source region End-member 2: in town Hybrid: around town fault Seismic Stations P-wave S-wave
Warning system designs Location of seismic network: End-member 1: in the earthquake source region End-member 2: in town Hybrid: around town fault Seismic Stations P-wave S-wave
Pakistan 2005 Muzaffarabad M 7.6 Uri Islamabad 80,000 fatalities poor construction many single story buildings
Pakistan 2005 Muzaffarabad: Regional capitol 20 km from epicenter 50% buildings destroyed Warning time: P-to-S: ~3 sec S-arrival: 6.5 sec best case 1-2 sec warning
Pakistan 2005 Uri: 60 km from epicenter 80% of buildings destroyed Warning time: P-to-S: 7.5 sec ~4 sec warning S-arrival: 18 sec 10+ sec warning
Pakistan 2005 Islamabad : Warning time: 105 km from epicenter P-to-S: 12 sec 8 sec warning S-arrival: 28 sec 20+ sec warning
Iran 2003 Bam: Warning time: 12 km from epicenter P-to-S: 1.5 sec S-arrival: 4 sec no warning Bam M 6.6
M 8.0 Peru 2007 Pisco: Warning time: 68,000 people 80% buildings destroyed 50 km from epicenter P-to-S: 6 sec 3 sec warning S-arrival: 15 sec 10 sec warning Pisco
M 8.0 Peru 2007 Ica: Warning time: 120,000 people 50% buildings destroyed 115 km from epicenter P-to-S: 16 sec 10 sec warning S-arrival: 35 sec 30 sec warning Ica
Summary There is rapid development and implementation of early warning around the world Adding a warning capability to seismic networks adds societal value Warning time Few seconds for in town station clusters Tens of seconds for regional networks High impact Poor/rudimentary construction results in high fatality rates Evacuation possible in a few seconds
ElarmS workshop UC Berkeley May 5-16, 2008 Week 1: Lectures and exercises to familiarize participants with the methodology and code Week 2: Assist participants to get the code running back in their home institutions Participants need to be self-supporting Contact: rallen@berkeley.edu More information at
Mitigating seismic hazard Different approaches for different timescales 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