HR: 0800h
AN: S51A-0217    [Abstracts]
TI: ShakeMap Implementation in Alaska
AU: * Martirosyan, A
EM: ffahm@uaf.edu
AF: University of Alaska Fairbanks, 903 Koyukuk dr., Fairbanks, AK 99775, United States
AU: Hansen, R
EM: roger@giseis.alaska.edu
AF: University of Alaska Fairbanks, 903 Koyukuk dr., Fairbanks, AK 99775, United States
AU: Robinson, M
EM: mitch@giseis.alaska.edu
AF: University of Alaska Fairbanks, 903 Koyukuk dr., Fairbanks, AK 99775, United States
AB: The ShakeMap (SM) system was developed by the USGS for generating and distributing real-time ground- shaking maps in the aftermath of significant earthquakes. SMs provide vital information within minutes after an earthquake to emergency response agencies, the media and the general public. It is also a tool to produce earthquake planning scenarios and to estimate losses from hypothetical strong earthquakes. SM production in Alaska is based on observed ground motion data (maximum peak ground accelerations and velocities of two horizontal components) and complemented by calculated values using empirical attenuation relationships. These data are collected from more than 80 broadband and 25 strong motion stations throughout the state. The real-time seismic operations in Alaska, including the SM system, are maintained at the Alaska Earthquake Information Center (AEIC) of the Geophysical Institute in Fairbanks. The earthquake parameters and waveform measurements are obtained within the Antelope seismic monitoring system. Currently, SMs are produced for events with magnitudes greater that M3.5 with at least 10 associated arrival picks. Moreover, the calculated intensity of the eligible events should be greater than 2.5 at the epicenter. With these settings, about 20 to 30 SMs are triggered in Alaska per month. The maps are generated and posted on the AEIC website 2-3 minutes after the event. The processing time mostly depends on the number of waveforms utilized in the calculation. Several SM updates may be issued for the same event as more reliable data become available. A manual run may be executed afterwards for significant events in order to utilize any additional information, such as extended source geometry or data from external sources.
DE: 7212 Earthquake ground motions and engineering seismology
DE: 7219 Seismic monitoring and test-ban treaty verification
DE: 7294 Seismic instruments and networks (0935, 3025)
SC: Seismology [S]
MN: 2007 Fall Meeting