HR: 1340h
AN: V53C-1419    [Abstracts]
TI: Gravity Data Confirm Addition of Mass Beneath Mauna Loa Volcano, Hawaii.
AU: * Battaglia, M
EM: maurizio.battaglia@uniroma1.it
AF: University of Rome "La Sapienza", Dept of Earth Sciences P.le A. Moro 5, Roma, 00185, Italy
AU: Amelung, F
EM: famelung@rsmas.miami.edu
AF: University of Miami, RSMAS/MGG 4600 Rickenbacker Causeway, Miami, FL 33149, United States
AU: Poland, M
EM: mpoland@usgs.gov
AF: USGS - Hawaiian Volcano Observatory, Reginald Okamura Building Crater Rim Road, Hawaii National Park, HI 96718, United States
AU: Kauahikaua, J
EM: jimk@usgs.gov
AF: USGS - Hawaiian Volcano Observatory, Reginald Okamura Building Crater Rim Road, Hawaii National Park, HI 96718, United States
AB: We combine deformation data from radar interferometry studies and measurements of changes in gravity at Mauna Loa over time to constrain the nature and time-dependent geometry of deep rift intrusions. We re-occupied 13 existing geodetic sites with a portable gravimeter (LR EG026) in the area of Mauna Loa's summit for two years. These sites are divided into two loops: a) Five sites of Mauna Loa's leveling network that have been occupied for gravity measurements several times since early 1984 by the USGS-Hawaiian Volcano Observatory. b) Eight sites of Mauna Loa's permanent GPS network. To check the quality of temporal gravity changes along the Mauna Loa gravity network, we established a control network of 5 stations from the NOAA Mauna Loa Observatory to BM6697 on the slope of Mauna Kea Volcano. Preliminary results show a gravity change of up to 0.210 ± 0.010 mGal at the Mauna Loa summit (benchmark ML1) between 2002 and 2006. The gravity changes posses a radial symmetry and becomes negligible at about 15 km from the summit. It is possible to fit the data with a point source with a depth of 4.7 km and a radius of 1.1 km (Amelung et al., 2007). The mass of the intrusion is about 0.9 MU (1 MU = 10¹² kg).
DE: 1217 Time variable gravity (7223, 7230)
DE: 1240 Satellite geodesy: results (6929, 7215, 7230, 7240)
DE: 8419 Volcano monitoring (7280)
DE: 8434 Magma migration and fragmentation
SC: Volcanology, Geochemistry, Petrology [V]
MN: 2007 Fall Meeting