Tracking velocity changes of the 2024 Kīlauea East Rift Zone eruption and preceding intrusions with ambient noise interferometry
Alicia Rohnacher 1, Ninfa Bennington2 , Federica Lanza1
Affiliations: 1 Swiss Seismological Service, ETH Zürich, Switzerland 2 U.S. Geological Survey, Hawaiian Volcano Observatory, Hawai'i, USA
Presentation type: Talk
Presentation time: Friday 10:45 - 11:00, Room R290
Programme No: 1.8.5
Abstract
The Kīlauea volcanic system on the Island of Hawaiʻi is renowned for its frequent eruptive activity, including summit crater and rift zone eruptions. In September 2024, Kīlauea experienced its first eruption in five years in the Middle East Rift Zone (MERZ) near Nāpau Crater, marking a shift from recent eruptions localized at the summit or the Southwest Rift Zone. This eruption, along with the preceding intrusive activity, was captured by a dense seismic nodal network comprising of 116 stations distributed over a 30×60 km area in the East Rift Zone (ERZ). Using ambient noise interferometry, we investigate magma-tectonic interactions by monitoring seismic velocity variations (dv/v) across space and time. These variations, which are influenced by both internal factors (magmatic and tectonic activity) and external forces (e.g., precipitation), are contextualized using data from the Hawaiian Volcano Observatory's permanent network of tiltmeters, GPS stations, and precipitation sensors. Initial results show a velocity decrease of up to 1% during the July 2024 intrusion event, correlating with increased seismicity and tilt changes both at the summit and in the MERZ. By incorporating volumetric strain modeling, we discuss the depth of the deformation source responsible for these changes, providing new insights into the processes driving the eruption. This study highlights how the integration of various geophysical observations can improve the understanding of volcanic precursors and magma dynamics and demonstrates the potential of dense seismic networks for volcano monitoring.