Collaborative Research: Characterizing Spatial and Temporal Variations of Volcanic Rift Zones on Basaltic Shield Volcanoes: A Seismological Study at Kilauea and Mauna Loa, Hawaii

Volcanic rift zones are key features of shield volcanoes such as the Hawaiian Islands. They accommodate the growth and spreading of volcanic edifices and, as areas of weakness, allow magma to travel laterally within the volcanoes and erupt far away from the summit, posing threats or causing damage to local communities and infrastructure. On May 3, 2018, one such eruption occurred in the Lower East Rift Zone of Kilauea. The eruption lasted for about 4 months, destroying over 700 buildings, and resulting in an estimated $800-million-dollar recovery cost. Four years later, Mauna Loa erupted in late 2022, for the first time since 1984. Outpouring lava flows from its Northeast Rift Zone almost reached the Daniel K. Inouye Highway, threatening to cut off the only highway that connects directly the east and northwest coasts of the Island of Hawaii. These two eruptions highlighted the knowledge gaps in our understanding of volcanic rift zones. This project aims to obtain detailed subsurface imaging of the rift zones and their spatial and temporal variations, which are essential for volcanic hazard mitigation. The project will collect seismic data including from a similar survey to one completed after the 2018 eruption. The project will also coordinate with collaborators from Switzerland who will be deploying seismic instruments around Kilauea in 2024. In collaboration with the USGS Hawaiian Volcano Observatory and Hawaii Volcanoes National Park Service, the results from this project will enable the development of new volcano monitoring capabilities and enhance societal preparedness against volcanic hazards. Four linear arrays consisting of 460 nodal geophones will be deployed in the first year of the project: One across the Kilauea Lower East Rift Zone (KLERZ), one across the Kilauea Middle East Rift Zone near Pu‘u‘ō‘ō, two across the Mauna Loa Northeast Rift Zone (MLNRZ) up-rift and down-rift of the 2022 eruption site. In the second year, the KLERZ line and the MLNRZ up-rift line will be re-deployed for constraints on temporal variations at the two locations. The main scientific goals of this project are to understand (1) the fine structures of the Mauna Loa and Kilauea rift zones and the differences between the two, (2) the relation between the fine structures and their volcano-tectonic settings, as well as the relation between the fine structures and the frequency and intensity of rift zone eruptions, (3) the post eruption changes and constraints on rift zone healing and cooling of the magma plumbing system, and (4) the long-term evolution of the Kilauea East Rift Zone. This project is funded by the Geophysics Program and Cross-cutting fund in the Division of Earth Sciences. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.