Operation of a telemetered seismic network on the Alaska Peninsula. Annual report

Technical Report · Wed Feb 01 04:00:00 EST 1978

OSTI ID:6799750

Pulpan, H

A large-aperture network of 11 short-period seismometers is being operated on the Alaska Peninsula and several offshore islands for the primary purpose of permitting data acquisition to study the seismotectonics of the area which is part of the Alaska-Aleutian arc-trench structure. Data from the network are routinely provided to Lamont-Doherty Geological Observatory in connection with a related program entitled ''Comprehensive Study of the Seismotectonics of the Aleutian Arc''. Technical improvements made during the report period have resulted in an over 90 percent reliability of the network between July 1977 and the present. Three strong motion instruments have been installed in that portion of the area which is part of a seismic gap. Seismic data accumulated from the network have permitted us to delineate the Benioff zone, the most prominent seismotectonic feature of the study area. Seismic activity in the suspected seismic gap area indeed appears lower than in other portions of the structure. Shallow seismicity, by and large diffuse throughout the area, clusters with great temporal and spatial variability along the line of volcanoes. Some of the clusters are probably associated with shallow magma chambers the existence of which is inferred from other work. Shallow seismic activity has been associated with the formation of two maars (initial perforation of the earth's crust by a rising magma front) in the study area.

• Research Organization: Alaska Univ., Fairbanks (USA). Geophysical Inst.
• OSTI ID: 6799750
• Report Number(s): RLO-2229-T6-5
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580201* -- Geophysics-- Seismology & Tectonics-- (1980-1989)
ALASKA
ALEUTIAN ISLANDS
COMMUNICATIONS
DATA ACQUISITION
DATA ACQUISITION SYSTEMS
DATA TRANSMISSION
ISLANDS
MEASURING INSTRUMENTS
NORTH AMERICA
PACIFIC NORTHWEST REGION
RELIABILITY
SEISMIC ARRAYS
SEISMIC DETECTORS
SEISMICITY
SEISMOGRAPHS
TECTONICS
TELEMETRY
USA