HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) References Citation Map Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by JACKSON, S. M. Articles by MARTIN, S. M. Search for Related Content GeoRef GeoRef Citation

Contemporary seismicity in the eastern Snake River Plain, Idaho based on microearthquake monitoring

IDAHO NATIONAL ENGINEERING LABORATORY EG & G IDAHO, INC., PO BOX 1625, MS 2107, IDAHO FALLS, IDAHO 83415
WOODWARD-CLYDE CONSULTANTS, 500 12TH ST. SUITE 100, OAKLAND, CALIFORNIA 94607

Abstract

Microearthquake monitoring by a permanent network operated since 1971 and two recent temporary surveys performed by the Idaho National Engineering Laboratory suggest that infrequent, small-magnitude earthquakes are characteristic of eastern Snake River Plain (ESRP) seismicity. Although a total of only 19 earthquakes have been observed to date, and not all have well-constrained focal depths, their relatively shallow occurrence at depths of 8 km is consistent with the hypothesis that elevated crustal temperatures in the ESRP confine the brittle portion of the crust, and hence seismogenesis, to the upper 6 to 10 km. A composite focal mechanism of two microearthquakes located near the axis of the ESRP indicates normal faulting with a minor component of strike-slip motion. The northeast-southwest-trending T-axis indicated by this composite mechanism is consistent with the direction of extension indicated by Holocene volcanic rift zones within the ESRP and normal faults in the adjacent Basin and Range province to the northwest. Based on this low level of small-magnitude seismicity, deviatoric stresses appear to be small in the ESRP.

Footnotes

^* Present address of S. M. Martin: B & V Waste Science Technology Corporation, 1201 Pacific Avenue, Suite 1100, Tacoma, Washington 98402.

This article has been cited by other articles:

				S. J. Payne, R. McCaffrey, and R. W. King Strain rates and contemporary deformation in the Snake River Plain and surrounding Basin and Range from GPS and seismicity Geology, August 1, 2008; 36(8): 647 - 650. [Abstract] [Full Text] [PDF]

				R. P. Smith Geologic Setting of the Snake River Plain Aquifer and Vadose Zone Vadose Zone J., February 1, 2004; 3(1): 47 - 58. [Abstract] [Full Text] [PDF]