Christine Chesley

Years participated in RESESS: 2011

Poster

An Overview

Academic Affiliation: The University of Miami

Biography

Christine was born in Detroit, Michigan, but has spent the majority of her life in Chesapeake, Virginia. As a student at the University of Miami, Christine is a ‘Cane (of the Hurricanes) for life, and bleeds orange and green. The bulk of credit for her interest in geology goes to her high school Earth Science teacher, Bill Dunn, and the Ocean Science Bowl team that he coached. She is a big fan of the Queen of Salsa, Celia Cruz, and when she’s not studying you can find her dancing to casino-style salsa.

Abstract

Great Nankai Earthquake triggers Mt. Fuji eruption: Stress change model of the 1707 Hoei Earthquake as a scenario of eruption promotion

Studies in magma-tectonics point to a spatiotemporal correlation between earthquakes and volcanic eruptions. Here we examine the correlation between two great earthquakes, the 1703 Mw8.2 Genroku and the 1707 Mw > 8.7 Hoei events in Japan, and Mt. Fuji’s explosive (VEI 5) Hoei eruption, 49 days after the 1707 earthquake. We modeled the static stress change and dilatational strain imparted on the Mt. Fuji magmatic system due to each earthquake to determine if these mechanisms enhanced the potential for eruption. Seismic and petrologic studies suggest that a basaltic magma chamber is located around 20 km depth and a dacitic chamber is at ~8 km depth. An andesitic chamber likely lies somewhere in between, as mixed andesite-dacite lavas were erupted in 1707. We modeled the magmatic system as a single, vertical dike that extended from the surface to 20 km depth so as to connect the magma chambers to each other and to the surface. Our modeling results show that both earthquakes compressed the magma chambers beneath Mt. Fuji and clamped the dike at 8 km. The 1703 earthquake, however, also clamped the dike at 20 km while the 1707 earthquake unclamped this segment of the dike.We hypothesize that the stress change and compressional strain generated by the 1707 earthquake triggered the eruption of Mt. Fuji by permitting the opening of the dike and the ascent of basaltic magma to the andesitic and dacitic magma chambers. The injection of basaltic magma into the more evolved magmatic system induced magma mixing and a Plinian eruption ensued.