Gravity changes and deformation at Kīlauea Volcano, Hawaii, associated with summit eruptive activity, 2009-2012

Journal of Geophysical Research
By: , and 

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Abstract

Analysis of microgravity and surface displacement data collected at the summit of Kīlauea Volcano, Hawaii (USA), between December 2009 and November 2012 suggests a net mass accumulation at ~1.5 km depth beneath the northeast margin of Halema‘uma‘u Crater, within Kīlauea Caldera. Although residual gravity increases and decreases are accompanied by periods of uplift and subsidence of the surface, respectively, the volume change inferred from the modeling of interferometric synthetic aperture radar deformation data can account for only a small portion (as low as 8%) of the mass addition responsible for the gravity increase. We propose that since the opening of a new eruptive vent at the summit of Kīlauea in 2008, magma rising to the surface of the lava lake outgasses, becomes denser, and sinks to deeper levels, replacing less dense gas-rich magma stored in the Halema‘uma‘u magma reservoir. In fact, a relatively small density increase (<200 kg m−3) of a portion of the reservoir can produce the positive residual gravity change measured during the period with the largest mass increase, between March 2011 and November 2012. Other mechanisms may also play a role in the gravity increase without producing significant uplift of the surface, including compressibility of magma, formation of olivine cumulates, and filling of void space by magma. The rate of gravity increase, higher than during previous decades, varies through time and seems to be directly correlated with the volcanic activity occurring at both the summit and the east rift zone of the volcano.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Gravity changes and deformation at Kīlauea Volcano, Hawaii, associated with summit eruptive activity, 2009-2012
Series title Journal of Geophysical Research
DOI 10.1002/2014JB011506
Volume 119
Issue 9
Year Published 2014
Language English
Publisher American Geophysical Union
Publisher location Washington, D.C.
Contributing office(s) Volcano Science Center, Hawaiian Volcano Observatory, Volcano Hazards Program
Description 18 p.
First page 7288
Last page 7305
Country United States
State Hawaii
Other Geospatial Kilauea Volcano
Online Only (Y/N) N
Additional Online Files (Y/N) N