NSF Award
2425360
This research will measure the deformation of the seafloor off Kīlauea volcano, Hawaiʻi at four sites for a 4-year period. Underlying the flank of the volcano is a nearly horizontal fault that is similar to the major earthquake faults at subduction zones. This study site makes a good natural laboratory to study this type of fault. This study also will reoccupy several sites last measured in 2004 to get a 20-year record of deformation. Over this time, the fault has experienced a major earthquake, on-going quiet creep, and a volcanic eruption in 2018. The combined deformation record will be 5 years of horizontal motion and 20 years of vertical uplift. Results will show where the fault slipped and how that slip is connected with earthquakes, sliding between earthquakes, and non-earthquake slip events. This research on Kīlauea's deformation will improve seismic and tsunami hazard assessments both in Hawai’i and at subduction zones. This project will train a graduate student. The data and products will contribute to community outreach and education efforts.<br/><br/>This project will support deployment of a seafloor geodesy network of 4 GNSS-Acoustic sites on the submarine south flank of Kīlauea volcano on the Big Island of Hawaiʻi to measure horizontal displacement rates along a profile above the Kīlauea décollement. Pressure surveys, reoccupying benchmarks previously measured in 2004, will determine the 20-year cumulative and the current vertical deformation rates. This structure has experienced regular slow-slip events, a major (Mw7.2) earthquake, persistent aseismic creep, and a pressure change within Kīlauea’s magmatic system following the dramatic 2018 eruption and summit collapse. Understanding which combination of seismic and aseismic slip processes occurring on discrete sections of the fault, and how they transfer stress, is critical to understanding the evolving stress state of the structure. Measuring deformation will answer several important questions: 1) What is the geometry of the fault system offshore? 2) Where does slip connected with earthquakes, interseismic creep, and slow-slip events occur? 3) What processes control stress transfer within the offshore fault system? 4) How do these tectonic processes respond to or impact volcanic events? A better understanding of the mechanical and dynamical behavior of Kīlauea’s submarine décollement will improve seismic and tsunamigenic hazard assessments both here and at subduction zones which have similar structures and active processes. This project will train a graduate student in seafloor geodesy, and the data and products generated by this project will contribute to community outreach and education efforts.<br/><br/>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.
