Seismotectonic study of seismic and volcanic hazards in the Pribilof Islands, eastern Aleutian Islands region of the Bering Sea
This report presents: (1) historic seismicity maps of the Shumagin seismic gap vicinity which show the relatively low level of seismic activity in the gap, a possible offset in the Benioff zone, and a few events associated with the Bering shelf continental margin south of the Pribilof Islands; (2) a seismicity map and hypocenter cross-sections based on data from the local Shumagin Islands seismic network which show a very well developed Benioff zone beneath the Shumagin Islands; (3) studies of the focal mechanisms of April 6, 1974 Shumagin Islands earthquake and the February 2, 1975 Near Islands earthquakes which respectively show thrust faulting perpendicular to the arc and right-lateral strike-slip faulting oblique to the arc along the slip direction inferred from the relative motion of the plates; (4) the first strong motion tians, which show accelerograph data from the eastern Aleutians, which show accelerations consistent with those observed for earthquakes in California; (5) this year's geodetic leveling results which when compared with those from 1972 indicate that regional tilting due to tectonic strain accumulation, if it is occuring, is less than 1.9 microradians per year; and (6) seismic observations of two Strombolian eruptive cycles of Pavolf Volcano which reveal monochromatic wave trains which are identical one to the next suggesting a common source region and a harmonic source function or very efficient filtering of body waves by the pyroclastic layers of the volcano.
- Research Organization:
- Lamont-Doherty Geological Observatory, Palisades, NY
- OSTI ID:
- 6365942
- Journal Information:
- Geology; (United States), Vol. 12
- Country of Publication:
- United States
- Language:
- English
Similar Records
Comprehensive study of the seismotectonics of the easter Aleutian arc and associated volcanic systems. Annual progress report, March 1, 1978--February 28, 1979
Comprehensive study of the seismotectonics of the eastern Aleutian arc and associated volcanic systems. Annual progress report, March 1, 1980-February 28, 1981
Related Subjects
02 PETROLEUM
ALASKA
RESOURCE DEVELOPMENT
SEISMOLOGY
REGIONAL ANALYSIS
TECTONICS
BERING SEA
CONTINENTAL SHELF
EARTHQUAKES
GEOLOGIC FAULTS
GEOPHYSICS
PETROLEUM INDUSTRY
SEISMIC WAVES
VOLCANOES
CONTINENTAL MARGIN
GEOLOGIC STRUCTURES
INDUSTRY
NORTH AMERICA
PACIFIC NORTHWEST REGION
PACIFIC OCEAN
SEAS
SEISMIC EVENTS
SURFACE WATERS
USA
510100* - Environment
Terrestrial- Basic Studies- (-1989)
520100 - Environment
Aquatic- Basic Studies- (-1989)
020900 - Petroleum- Environmental Aspects