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

Autor: John Henderson, D. J. Barton, Gillian R. Foulger, Bruce R. Julian
Rok vydání: 1999
Předmět:
Zdroj: Geophysical Journal International. 138:563-570
ISSN: 1365-246X
0956-540X
DOI: 10.1046/j.1365-246x.1999.00898.x
Popis: SUMMARY 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 northnorthwesterly 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 largemagnitude seismic activity in the past. Seismicity on this structure was characterized by low b-values and relatively high D. These observations are consistent with lowmagnitude, clustered earthquakes on the first structure, and higher-magnitude, diVuse 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.
Databáze: OpenAIRE
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