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Results of a VSP experiment at the Resurgent Dome, Long Valley caldera, California
Author(s) -
Gritto Roland,
Romero Arturo E.,
Daley Thomas M.
Publication year - 2004
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2004gl019451
Subject(s) - dome (geology) , caldera , geology , seismology , volcano , geomorphology
A vertical seismic profiling experiment has been conducted at the DOE well LVF 51–20 at the resurgent dome at Long Valley caldera, California. The current paper is intended to report the velocity results derived from this experiment to seismically constrain the area around the resurgent dome. We report the results of velocity logs, V p / V s ratios, and V p V s products for the depth interval from 880–1980 m. The Bishop tuff can be divided into three zones (top‐to‐bottom) of intermediate velocities ( V p ≈ 4.0 km/s, V s ≈ 2.3 km/s), followed by higher velocities ( V p = 4.7 km/s, V s = 2.9 km/s) in the lower‐central part, and a decrease back to the lower values at the bottom of the sequence. The analysis of V p V s data suggested a decrease in porosity in the lower‐central section of the tuff as a possible explanation, which was supported by direct density measurements from a nearby location.