Crustal stress and structure at Kīlauea Volcano inferred from seismic anisotropy: Chapter 12

Geophysical Monograph - 12
By: , and 
Edited by: Rebecca CareyValérie CayolMichael P. Poland, and Dominique Weis

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Abstract

Seismic anisotropy, measured through shear wave splitting (SWS) analysis, can be indicative of the state of stress in Earth's crust. Changes in SWS at Kīlauea Volcano, Hawai‘i, associated with the onset of summit eruptive activity in 2008 hint at the potential of the technique for tracking volcanic activity. To use SWS observations as a monitoring tool, however, it is important to understand the cause of seismic anisotropy at the volcano throughout the eruptive cycle. To address this need, we analyzed SWS results from across Kīlauea in combination with macroscopic surface structures (mapped fractures, faults, and fissures) and stress orientations inferred from fault plane solutions. Seismic anisotropy seems to be due to pervasive aligned structures in most regions of the volcano. The upper East and Southwest Rift Zones, however, show a bimodality in stress and SWS, suggesting a stress discontinuity with depth, perhaps related to magma conduits that trend obliquely to the dominant structure. Other areas in and around Kīlauea Caldera display principal stresses of similar magnitudes, indicating that small stress perturbations can rotate the maximum horizontal compressive stress direction by up to 90°. In these locations, static structures generally control SWS, but dynamic conditions due to magmatic activity can override the structural control. Monitoring of SWS may therefore provide important signs of impending volcanism.

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Additional publication details

Publication type Book chapter
Publication Subtype Book Chapter
Title Crustal stress and structure at Kīlauea Volcano inferred from seismic anisotropy: Chapter 12
Series title Geophysical Monograph
Chapter 12
ISBN 978-1-118-87204-8
DOI 10.1002/9781118872079.ch12
Volume 208
Year Published 2015
Language English
Publisher American Geophysical Union; John Wiley & Sons
Publisher location Washington, D.C.
Contributing office(s) Volcano Science Center
Description 18 p.
Larger Work Type Book
Larger Work Subtype Monograph
Larger Work Title Hawaiian volcanoes: From source to surface
First page 251
Last page 268
Conference Title AGU Chapman Conference
Conference Location Waikoloa, Hawai'i
Conference Date August 20-24, 2012
Country United States
State Hawaii
Other Geospatial Kīlauea volcano
Online Only (Y/N) N
Additional Online Files (Y/N) N