Receiver Function Imaging of Kīlauea Using Broadband and Nodal Seismometers

Abstract

Constraining the locations of magma storage at volcanoes helps improve our understanding of eruption processes and interpretations of volcano seismicity. A recent surge in deep seismicity beneath the Pāhala region on the Island of Hawai‘i prompted the 2022 deployment of nodal seismometers to seismically image the Southwest Rift Zone of Kīlauea. Using data recorded during 2022 and 2018 nodal deployments on Kīlauea, as well as data recorded from 2010 - 2022 by the nearby permanent broadband network maintained by the Hawaiian Volcano Observatory, we calculate teleseismic receiver functions, a traditional seismic imaging technique sensitive to abrupt changes in velocity, to image the crustal structure of Kīlauea. The use of nodal seismometers for passive seismic imaging targets has significantly expanded over the past decade, even though they are primarily sensitive to a higher frequency range than broadband seismometers. We utilize the broadband data to ensure reliability of the nodal data and expand our imaging scope across the Island of Hawai‘i. Using forward modeling techniques to analyze the receiver functions, we identify the potential presence of magma sills at the Southwest Rift Zone. Future work should include analysis of complementary datasets, and more sophisticated modeling techniques to rule out other potential structures.