Grant-in-Aid for international Scientific Research
|Allocation Type||Single-year Grants |
|Research Institution||KYOTO UNIVESITY |
TANAKA Torao Kyoto University, DPRI,Professor, 防災研究所, 教授 (40027222)
SUPARKA S Academy of Science of Indonesia, Vice-Chairman, 副会長
KAHAR Joenil ITB,Department of Geod.Engineering, Professor, 測地工学科, 教授
NAKAURA Kajuro Kyoto University, DPRI,Research Associate, 防災研究所, 助手 (20135510)
OKUBO Shuhei University, of Tokyo, ERI,Professor, 地震研究所, 教授 (30152078)
ANDO Masataka Kyoto University, DPRI,Professor, 地震研究所, 教授 (80027292)
大谷 文夫 京都大学, 防災研究所, 助手 (90027293)
伊藤 潔 京都大学, 防災研究所, 助教授 (80022721)
三浦 哲 東北大学, 理学部, 助手 (70181849)
藤森 邦夫 京都大学, 理学研究科, 助手 (00025470)
重富 國宏 京都大学, 防災研究所, 助手 (40025458)
江頭 庸夫 京都大学, 防災研究所, 助手 (00027236)
井口 正人 京都大学, 防災研究所, 助教授 (60144391)
|Project Period (FY)
1996 – 1997
Completed (Fiscal Year 1997)
|Budget Amount *help
¥7,100,000 (Direct Cost: ¥7,100,000)
Fiscal Year 1997: ¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 1996: ¥3,600,000 (Direct Cost: ¥3,600,000)
|Keywords||active volcano / GPS / fault / leveling survey / gravity measurement / seismographic obsevation / IGSN1971 / GPS観測 / 地殻構造 / 地震活動 / 地質構造 / テクトニクス / 国際重力基準網|
Gravity survey was carried out crossing the Lembang and Cimandiri Faults. Gravity measurements were made with 500n intervals, and GPS observations were also made for precise positioning. A preliminary analysis shows that there is a density contrast between both sides of the faults and that the existence of a layer which tilts to north is expected.
A Reconnaissance seismic observation near the Lembang fault was carried out for about 10 days in October 1997. Two seismographs were set near the Lembang fault. The seismograph consists of three component seismometers with a natural frequency of 2Hz, a digital recorder and a GPS receiver for timing. The recorder has an amplifier, a 16 bit AD-converter and DAT recording system. Some small earthquakes were observed during the observation period. According to reports of the volcanic activity, seismic swarms sometimes occur near active volcanoes. Therefore, seismic activity for small earthquake is not so low near the volcanoes, but not so high near the Lembang fault.
GPS network extended in 1996 was repeatedly observed with Ashtech Z12 and Leica System 300 receivers. The network consists of 7 stations. The size of the network is about 10km and the prcision of positioning is a few mm in rms in average. From repeated GPS measurements a deformation which seems to indicate the buldge of the body of Guntur volcano was detected. Though the deformation is small compared with the positioning precision, it is in agreement with the result from leveling survey at the southeastern foot of the volcaco.
In December 1997 an international symposium was held in Kyoto and investigators of this project participated in the symposium and special meeting in order to discuss the results of this program about the tectonics and structure of Lembang and Cimandiri faults.