Receiver Function Imaging of Kīlauea using Nodal and Broadband Seismometers

Constraining the locations of magma storage at volcanoes helps improve our understanding of eruption processes and interpretations of volcano seismicity. Using data recorded by nodal and broadband seismometers deployed on the Big Island of Hawaiʻi, we calculate teleseismic receiver functions, a traditional seismic imaging technique sensitive to abrupt velocity boundaries, to image the crustal structure of Kīlauea. The use of nodal seismometers for passive seismic imaging targets has significantly expanded over the past decade. They are primarily sensitive to a higher frequency range than broadband seismometers. However, due to their smaller size and lower cost, they are easier to deploy in larger numbers, and in sensitive or difficult to access environments, facilitating denser arrays in novel locations. Previous studies have successfully leveraged the dense deployment design to image shallow crustal features that would otherwise be aliased by the typical spacing of broadband instruments, as well as image deeper structures in equal or greater detail than broadband deployments using receiver functions. We apply this technique on teleseismic earthquakes recorded during a 2018 rapid nodal deployment at the caldera and lower East Rift Zone of Kīlauea, and aim to expand our analysis to a 2022 nodal deployment on the Southwest Rift Zone. We ground-truth the nodal data against data from the nearby permanent broadband network maintained by the Hawaiian Volcano Observatory. Additionally, we use the broadband data from 2009-2021 to create a sparser background model of Kīlauea. The analysis of these data sets will combine to reveal new insights on the complex plumbing systems of Kīlauea.