LOCAL SEISMIC MONITORING.

• Main Authors: Westphal, Warren H., Lange, Arthur L.
• Other Authors: STANFORD RESEARCH INST MENLO PARK CA
• Format: Text
• Language: English
• Published: 1966
• Subjects: Seismology; (*NUCLEAR EXPLOSIONS; ALASKA); (*SEISMIC WAVES; UNITED STATES); UNDERGROUND EXPLOSIONS; SHOCK WAVES; MICROSEISMS; INTENSITY; EARTHQUAKES; SEISMOGRAPHS; PORTABLE EQUIPMENT; FAULTS(GEOLOGY); STRUCTURAL GEOLOGY; EPICENTERS; ARIZONA; NEVADA; CALIFORNIA; UTAH; OREGON; DETECTION; NETWORKS; COMPUTER PROGRAMMING; ALEUTIAN ISLANDS; MONITORS; LONG SHOT; Alaska; Aleutian Islands
• Online Access: http://www.dtic.mil/docs/citations/AD0484051; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=AD0484051

Four, low-power, portable seismographs were constructed. From August 1964 to October 1965, these seismographs were used to record local seismic activity in eight geographical areas in the conterminous U.S. and seismic signals at regional distances from the LONG SHOT explosion in Alaska. The resulting data indicated that most seismic activity can be related to specific geologic structures and that the level of the activity is quite variable in time. Periods of activity in a specific geologic structure are usually accompanied by higher magnitude (4-5) earthquakes. Aftershock sequences of these larger magnitude shocks, at least in three cases observed in western Nevada, appear to terminate within a few hours or at the most a few days after the main shock.