Geological and Geophysical Investigations on Kīlauea and Mauna Loa Volcanoes, Hawai‘i

Abstract

This dissertation presents four projects carried out on Kīlauea and Mauna Loa volcanoes on the Island of Hawai‘i. Broadly, two of the projects relate to geological field operations, whereas the other two relate to geophysical data interpretation. Chapter 1 conveys how the U.S. Geological Survey’s (USGS) Hawaiian Volcano Observatory (HVO) modified its interdisciplinary monitoring strategies to respond to the 2018 eruption of Kīlauea volcano by adding 35 new stations and re-routing data telemetry links to ensure both eruption sites in the lower East Rift Zone (LERZ) and Summit were adequately monitored. Over the course of the eruption, lava, ashfall, wildfire, and cliff collapse destroyed or disabled 36 stations. Chapter 2 describes the HVO earthquake catalog of more than 60,000 events during the 2018 Kīlauea eruption, broken into the three main seismic sequences: the LERZ eruption, the magnitude-6.9 Kalapana earthquake with south flank aftershock sequence, and 63 episodic caldera collapse cycles that include 62 ~magnitude-5 major collapse events. Catalog statistics, spatiotemporal patterns, and other metrics are discussed. Chapter 3 details 21 geological field tasks that were developed and assigned to analog astronaut crews during long-duration simulated missions ranging in duration from 4-12 months in 2013-2018 at the Hawai‘i Space Exploration Analog and Simulation (HI-SEAS) site on Mauna Loa volcano. Crew performance for each task and comparison of the results across missions reveal insights into varying crew performance over time, including weak third quarter performance dips for some missions. Chapter 4 presents results from four geophysical surveys (ground penetrating radar, magnetic, seismic refraction, and LiDAR) conducted over a known lava tube near the HI-SEAS site in order to evaluate which types of surveys can most easily can detect and characterize lava tubes on young volcanic terrain. Magnetic surveys were most effective in detecting the lava tube, and forward modeling helps place bounds on the tube radius to 3-4 meters diameter and depth of 5-7 meters.