thumbnail

HIGH-FREQUENCY OBSERVATIONS AND SOURCE PARAMETERS OF MICROEARTHQUAKES RECORDED AT HARD-ROCK SITES.

Bulletin of the Seismological Society of America

By:
, ,

Links

  • The Publications Warehouse does not have links to digital versions of this publication at this time

Abstract

We have estimated the source parameters of 53 microearthquakes recorded in July 1983 which were aftershocks of the Miramichi, New Brunswick, earthquake that occurred on 9 January 1982. These events were recorded by local three-component digital seismographs at 400 sps/component from 2-Hz velocity transducers sited directly on glacially scoured crystalline basement outcrop. Hypocentral distances are typically less than 5 km, and the hypocenters and the seven digital seismograph stations established all lie essentially within the boundaries of a granitic pluton that encompasses the faults that ruptured during the main shock and major aftershocks. The P-wave velocity is typically 5 km/sec at the surface and at least 6 km/sec at depths greater than about 1 km. The events have S-wave corner frequencies in the band 10 to 40 Hz, and the calculated Brune model seismic moments range from 10**1**5 to 10**1**8 dyne-cm. The corresponding stress drops are generally less than 1. 0 bars, but there is considerable evidence that the seismic-source signals have been modified by propagation and/or site-effects.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
HIGH-FREQUENCY OBSERVATIONS AND SOURCE PARAMETERS OF MICROEARTHQUAKES RECORDED AT HARD-ROCK SITES.
Series title:
Bulletin of the Seismological Society of America
Volume
75
Issue:
6
Year Published:
1985
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Bulletin of the Seismological Society of America
First page:
1535
Last page:
1567
Number of Pages:
33