HR: 0800h
AN: V21D-0646    [Abstracts]
TI: Vocanic Deformations During Repose Interval Revealed by GPS Measurements, Batur Volcano, Indonesia
AU: * Nishimae, K
EM: nisimae@eps.nagoya-u.ac.jp
AF: Graduate school of Environmental studies, Nagoya University, Nagoya Univercity Furo-cho chikusa-ku, Nagoya, 464-8602 Japan
AU: Fujii, N
EM:
AF: Graduate school of Environmental studies, Nagoya University, Nagoya Univercity Furo-cho chikusa-ku, Nagoya, 464-8602 Japan
AU: Kimata, F
EM:
AF: Graduate school of Environmental studies, Nagoya University, Nagoya Univercity Furo-cho chikusa-ku, Nagoya, 464-8602 Japan
AU: Murase, M
EM:
AF: Graduate school of Environmental studies, Nagoya University, Nagoya Univercity Furo-cho chikusa-ku, Nagoya, 464-8602 Japan
AU: Suganda, O K
EM:
AF: Department of Geodesi Engineering,Institute of Technology Bandung, Jl. Ganesa No.10, Bandung, Bandung, 40132 Indonesia
AU: abidin, H Z
EM:
AF: Department of Geodesi Engineering,Institute of Technology Bandung, Jl. Ganesa No.10, Bandung, Bandung, 40132 Indonesia
AB: Batur volcano is located north west of Bali Island in Indonesia.This volcano has two calderas with more than 10 km in diameter. Recent eruptions with lava flow occurred in 1963 and 1974. No effusion of lava has been observed since 1990, although steam explosions occurred August 1994, November 1997 and June 1998.This suggests that magmatic activity of this volcano would keep its high level since 1994.GPS observation network of this volcano has been kept by Institute Technology of Bandung (ITB) and Volcano Survey of Indonesia (VSI).The network was consisted of 10 observation points at the beginning in 1999, and now it becomes 23 observation points. We have made GPS campaign observations about five times from 2003 to 2005. Each campaign observation consisted of a couple of days of measurements for each observation point. In order to keep the quality of data as high as possible, observations have been made at least 12 hours of continuous data for each point. In this report, results of two campaign observations (December 2004 and July 2005) are used for the analysis. The data thus obtained are fitted to the Mogi source (i.e. a point source model) to locate the depth and amount of volume changes for 7 months. Location of the Mogi source was obtained about 4km southeast of the summit of central cone, and 3km depth with deflation volume change of 1.3_~10⁶ m³ for about 7months. For the period from 1999 to 2004, estimated volume change suggests a continuous deflation throughout this period, although the reliability of data was not so high. Continuous deflations might be likely after the last effusive eruption in 1974, would suggest that shallow part of magma beneath the central cone would probably be drained down to further deep, or shrinkage of magma associated with the cooling or solidification. Further data are obviously needed to discriminate the mechanisms of the deformation process during the repose period in this volcano.
DE: 0798 Modeling
DE: 7280 Volcano seismology (8419)
DE: 8434 Magma migration and fragmentation
DE: 8440 Calderas
DE: 9320 Asia
SC: Volcanology, Geochemistry, Petrology [V]
MN: Fall Meeting 2005