Publication Date:
2015-10-07
Description:
We present high-resolution compressional- to shear-wave velocity ratios ( V p / V s ) beneath Kı̄lauea's summit caldera by applying an in situ estimation method using waveform cross-correlation data for three similar earthquake clusters. We observe high V p / V s ratios (1.832 and 1.852) for two event clusters surrounded by the low background V p / V s value of 1.412 at ∼2.1 km depth below the surface. These high and low V p / V s ratios can be explained by melt- and CO 2 -filled cracks, respectively, based on a theoretical crack model. The event cluster with the highest V p / V s ratio consists of long-period events that followed the 1997 East Rift Zone eruption, indicating their association with fluid and magma movement. The depths of the two clusters with high V p / V s ratios are consistent with the magma reservoir location inferred from geodetic observations. Their locations east and north of Halema‘uma‘u crater suggest a horizontal extent of a few kilometers for the reservoir.
Print ISSN:
0094-8276
Electronic ISSN:
1944-8007
Topics:
Geosciences
,
Physics
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