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Magma intrusion beneath Long Valley caldera confirmed by temporal changes in gravity

Science

By:
, ,
DOI: 10.1126/science.285.5436.2119

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Abstract

Precise relative gravity measurements conducted in Long Valley (California) in 1982 and 1998 reveal a decrease in gravity of as much as -107 ?? 6 microgals (1 microgal = 10-8 meters per square second) centered on the uplifting resurgent dome. A positive residual gravity change of up to 64 ?? 15 microgals was found after correcting for the effects of uplift and water table fluctuations. Assuming a point source of intrusion, the density of the intruding material is 2.7 x 103 to 4.1 x 103 kilograms per cubic meter at 95 percent confidence. The gravity results require intrusion of silicate magma and exclude in situ thermal expansion or pressurization of the hydrothermal system as the cause of uplift and seismicity.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Magma intrusion beneath Long Valley caldera confirmed by temporal changes in gravity
Series title:
Science
DOI:
10.1126/science.285.5436.2119
Volume
285
Issue:
5436
Year Published:
1999
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Science
First page:
2119
Last page:
2122
Number of Pages:
4