Operation of a telemetered seismic network on the Alaska Peninsula. Annual report
A large aperture network of eleven short period seismic stations is being operated on the Alaska Peninsula and several offshore islands to acquire data for the study of the seismotectonics of a part of the Alaska-Aleutian arc-trench structure. The system operated satisfactorily during the past year and continued to provide seismic coverage at a low magnitude threshold level (M/sub L/ = 2.0). An event detection system, developed under this contract over the past years, has been field installed and is undergoing fine tuning. Focal mechanism studies of intermediate depths Benioff zone earthquakes were continued. Like a previous, smaller set, these mechanisms show predominantly down-dip extension, indicating gravitational sinking of the subducting lithosphere. Analysis of the combined data from our network and a temporary array of Ocean Bottom Seismometers, deployed under a related study, indicate that epicenters of earthquakes in the continental shelf area off Kodiak Island are shifted landward by about 15 km with respect to the epicenters determined from the combined data set. Clusters of shallow seismic activity associated with certain Alaska Peninsula volcanoes, observed over the past years, had previously been interpreted as related to shallow magmatic-geothermal reservoirs. Volcanologic-petrologic field studies conducted last year show that volcanic centers associated with such swarms do indeed have surface manifestations of hydrothermal activity.
- Research Organization:
- Alaska Univ., Fairbanks (USA). Geophysical Inst.
- DOE Contract Number:
- AT06-76ER70006
- OSTI ID:
- 6526012
- Report Number(s):
- DOE/ER/70006-7; RLO-2229-T6-7
- Country of Publication:
- United States
- Language:
- English
Similar Records
Operation of a telemetered seismic network on the Alaska Peninsula
Comprehensive study of the seismotectonics of the Aleutian arc. Annual progress report, March 1, 1976--February 28, 1977
Related Subjects
580201* -- Geophysics-- Seismology & Tectonics-- (1980-1989)
ALASKA
ALEUTIAN ISLANDS
CONTINENTAL MARGIN
CONTINENTAL SHELF
DETECTION
EARTHQUAKES
ISLANDS
MEASURING INSTRUMENTS
NORTH AMERICA
PACIFIC NORTHWEST REGION
RESEARCH PROGRAMS
SEISMIC ARRAYS
SEISMIC DETECTION
SEISMIC EVENTS
SEISMICITY
USA
VOLCANOES