Seismic response of the Katmai volcanoes to the 6 December 1999 Magnitude 7.0 Karluk Lake Earthquake, Alaska
Power JA, Moran SC, McNutt S, Stihler S, Sanchez JJ. 2001. Seismic response of the Katmai volcanoes to the 6 December 1999 Magnitude 7.0 Karluk Lake Earthquake, Alaska. Bulletin of the Seismological Society of America. 91(1):57-63
A sudden increase in earthquake activity was observed beneath volcanoes in the Katmai area on the Alaska Peninsula immediatley following the 6 December 1999 magnitude 7.0 Karluk Lake earthquake beneath southern Kodiak Island, Alaska. The observed increase in earthquake activity consisted of small, shallow events. These earthquakes were located beneath Mount Martin, Mount Mageik, Trident Volcano, and the Katmai caldera and began within the coda of the Karluk Lake mainstock. All of these earthquakes occured in areas and magnitude ranges that are typical for the background seismicity observed in the Katmai area. Seismicity rates returned to background levels 8 to 13 hours after the Karluk Lake mainshock. The close temporal relationship with the Karluk Lake mainshock, the onset of activity within the mainshock coda, and the simultaneous increase beneath four separate volcanic centers all suggest these earthquakes were remotely triggered. Modeling of the Coulomb stress changes from the mainshock for optimally oriented faults suggests negligible change in static stress beneath the Katmai volcanoes. The result favors models that involve dynamic stresses as the mechanism for triggered seismicity at Katmai.
- Type
- Journal Article
- Authors
- Power, J; Moran, S; McNutt, SR; Stihler, SD; Sanchez, J
- Units
- KATM
- Keywords
- Alaska, Karluk Lake Earthquake, Katmai National Park And Preserve, Katmai Volcanoes, Seismic Response, Volcanoes