Geophysical investigations of the western Ohio-Indiana region. Technical report (final) Nov 75-Sep 81

Technical Report · Fri Jan 01 04:00:00 EST 1982

OSTI ID:5101372

Jackson, P L; Christensen, D H; Mauk, F H

The geophysical investigations of the Western Ohio and Indiana regions include the maintenance of a precision seismograph network to monitor earthquake activity. Data generated by this network, supplemented with other information, are used to analyze regional seismicity and to interpret the local geologic and seismotectonic structure. Four array stations in Indiana were added to the nine stations near Anna, Ohio, and the Ohio stations were upgraded by replacing seismometers and installing more stable electronic systems. A new digital computer with analog-to-digital convertors was obtained for direct digital recording and other digital analysis. Ten small earthquakes in the Anna region were recorded, six in a very tight cluster near the village of Anna. Only one of the earthquakes was felt. P-wave studies show an azimuthally dependent difference in residuals between stations within the Western Ohio array--a difference which can only be caused by significant variation in local structure. Aftershocks were recorded, public responses obtained and classified, and intensity contours drawn for the 5.1 magnitude earthquake on July 27, 1980, in Sharpsburg, Kentucky.

• Research Organization: Michigan Univ., Ann Arbor (USA)
• OSTI ID: 5101372
• Report Number(s): NUREG/CR-2484
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580201* -- Geophysics-- Seismology & Tectonics-- (1980-1989)
DETECTION
EARTHQUAKES
FEDERAL REGION V
GEOLOGIC FAULTS
GEOLOGIC STRUCTURES
GEOPHYSICAL SURVEYS
INDIANA
MEASURING INSTRUMENTS
NORTH AMERICA
OHIO
SEISMIC ARRAYS
SEISMIC DETECTION
SEISMIC EVENTS
SEISMIC WAVES
SURVEYS
USA