Options
Gravity changes and deformation at Kīlauea Volcano, Hawaii, associated with summit eruptive activity, 2009–2012
Author(s)
Language
English
Obiettivo Specifico
2V. Dinamiche di unrest e scenari pre-eruttivi
Status
Published
JCR Journal
JCR Journal
Peer review journal
Yes
Title of the book
Issue/vol(year)
/119 (2014)
ISSN
0148-0227
Publisher
American Geophysical Union
Pages (printed)
7288–7305
Issued date
2014
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 kgm_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.
Type
article
File(s)
No Thumbnail Available
Name
Bagnardi_KilaueaGravity_JGR_2014.pdf
Description
Main article
Size
2.09 MB
Format
Adobe PDF
Checksum (MD5)
cd1bcaa4901b5ee50b42b05e281d3e8b