HR: 1330h
AN: S12A-0364    [PDF]
TI: Aftershock Recordings of Nenana Mt. and Denali Fault Earthquakes of 2002
AU: * Estes, S A
EM: estes@gi.alaska.edu
AF: Geophysical Institute, University of Alaska 903 Koyukuk Dr. P.O. Box 757320, Fairbanks, AK 99775-7320
AU: Stachnik, J
EM: josh@giseis.alaska.edu
AF: Geophysical Institute, University of Alaska 903 Koyukuk Dr. P.O. Box 757320, Fairbanks, AK 99775-7320
AU: Hansen, R A
AF: Geophysical Institute, University of Alaska 903 Koyukuk Dr. P.O. Box 757320, Fairbanks, AK 99775-7320
AB: Recent large earthquakes (M6.7, M7.9) in central Alaska ruptured the Denali Fault in late 2002. This rare opportunity to study this complex fault system required a substantial effort to obtain quality seismic data through the installation of a temporary seismic network. Less than one month after the M7.9 earthquake on November 3, 2002 twenty-six temporary sites were installed within 100 km of the Denali Fault. Of these 26 stations, 12 were Guralp 5-TD strong motion accelerometers recording triggered signals based on site-specific STA/LTA parameters to flash memory. The remaining 14 sites contained broadband seismometers (Guralp 40T or Guralp 3T) recording continuously to Reftek 72A-08 digital acquisition systems with 16- or 24-bit digitization and stored on Reftek 72A-05 hard drives. Stations were visited about every three weeks and remained in operation until the end of June 2003. The success of data recovery was inhibited by faulty power systems and inoperative equipment in harsh, remote Alaskan conditions. Installation and maintenance of this temporary network was performed by Alaska Earthquake Information Center (AEIC) personnel, with equipment provided by AEIC, PASSCAL, and the USGS. Data collected from the Denali Fault temporary network proved indispensable for the location of over 16,000 aftershocks between October 23 and the end of November 2002. Subsequently, we expanded the permanent broadband array along the Denali Fault westward of the 2002 rupture zone. In addition, one of the temporary sites (HARP) has become permanent. Data from this expanded network is recorded in real-time.
UR: http://www.aeic.alaska.edu
DE: 7200 SEISMOLOGY
DE: 7294 Instruments and techniques
SC: Seismology [S]
MN: 2003 Fall Meeting