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Frequency-magnitude statistics and spatial correlation dimensions of earthquakes at Long Valley caldera, California

Geophysical Journal International

By:
, , ,
DOI: 10.1046/j.1365-246X.1999.00898.x

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Abstract

Intense earthquake swarms at Long Valley caldera in late 1997 and early 1998 occurred on two contrasting structures. The first is defined by the intersection of a north-northwesterly array of faults with the southern margin of the resurgent dome, and is a zone of hydrothermal upwelling. Seismic activity there was characterized by high b-values and relatively low values of D, the spatial fractal dimension of hypocentres. The second structure is the pre-existing South Moat fault, which has generated large-magnitude seismic activity in the past. Seismicity on this structure was characterized by low b-values and relatively high D. These observations are consistent with low-magnitude, clustered earthquakes on the first structure, and higher-magnitude, diffuse earthquakes on the second structure. The first structure is probably an immature fault zone, fractured on a small scale and lacking a well-developed fault plane. The second zone represents a mature fault with an extensive, coherent fault plane.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Frequency-magnitude statistics and spatial correlation dimensions of earthquakes at Long Valley caldera, California
Series title:
Geophysical Journal International
DOI:
10.1046/j.1365-246X.1999.00898.x
Volume
138
Issue:
2
Year Published:
1999
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
First page:
563
Last page:
570
Number of Pages:
8