This research involves the investigation of the nature of the rift-flank system of Kilauea volcano, Hawaii, using data from a portable seismograph array deployment. One target of the array is to record the seismic waves generated by earthquakes whose seismic waves propagate through the deep part of the Kilauea East Rift Zone in order to detect the possible presence of a postulated deep magma body underlying the zone. If the deep magma body exists, the array should detect strongly increased attenuation (or possibly complete shadowing) of shear waves compared to paths that do not propagate through the deep part of the rift, and may record converted or reflected waves from the edge of the deep magma zone. A second target of the array is to investigate the nature of the interface between Kilauea's volcanic pile and the underlying oceanic crust (the basal interface), and the relationship between that interface and the seismically active zones beneath the South Flank. There is a continuing question as to the location of the fault surface of the 1975 Kalapana, magnitude 7.2, earthquake on or near this interface. The seismic array data will be used to (a) derive local models of Vp and Vs structure of the South Flank, (b) determine high-precision relative locations of South Flank earthquakes to resolve the geometry of the seismically active zones, particularly along the central portion of the rupture zone of the 1975 earthquake, and (c) image the basal interface using Sp converted waves to assess the spatial relationship between the basal interface and the seismically active zones. This research is a component of the National Earthquake Hazard Reduction Program.
