Applications of the State-of-the-Art Seismic Analysis Methods to the Island of Hawaii

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Hawaii is one of the most seismically active regions in the world and has been serving as a natural laboratory for studying the interactions between seismic and magmatic processes for the past few decades. We propose a two-year program to apply the state of the art seismic analysis techniques that take advantage of waveform cross-correlation to the Island of Hawaii to assess the fine-scale near-source spatial and temporal volcanic structural variations and to improve earthquake locations. The data to be used in the proposed research are the digital seismic data from the USGS Hawaiian Volcano Observatory and temporary seismic stations for about 150,000 earthquakes. The objective of this application is to integrate seismic data of Hawaii to better understand the nature of the near-source seismic parameters. In the proposed research, we will pursue the following five specific tasks to the entire Island of Hawaii: (1) to calculate both compressional and shear wave differential times by using waveform cross-correlation, (2) to image the magmatic system using the most recent tomography algorithm to a composite event data set, (3) to perform similar event cluster analysis and cross-correlation relocation, (4) to estimate high-resolution in situ Poisson's ratio using waveform data, and (5) to examine temporal variations in seismic parameters. The newly developed velocity models will be used to resolve conduits and magma chambers and to improve absolute earthquake locations. In situ Poisson's ratios with high-resolution will be of great help to track magma moving and estimate fraction of partial melt. These results will better constrain earthquake locations for a new relocation catalog based on waveform cross-correlation data. Our results will address the following questions: (1) what will the simultaneous inversions of the high-resolution three-dimensional (3-D) velocity models reveal about the magmatic system and possible magma bodies? (2) What will the absolute location constraints from 3-D velocity models tell us about the fault zones in Mauna Loa and Kilauea? (3) What will the high-resolution in situ near-source parameters estimated from waveform cross-correlation data reveal about the spatial and temporal characteristics in the near-source region? (4) How do the long-lasting seismic velocity variations in Hawaii compare to other regions? The results from this study will generate a public database of information suitable for the geology, tectonics, and volcanology communities.