HR: 0800h
AN: G51C-0619    [Abstracts]
TI: Crustal Deformation Caused by Earthquake Detected by InSAR Technique Using ALOS/PALSAR Data
AU: * Miyagi, Y
EM: miyagi.yousuke@jaxa.jp
AF: Japan Aerospace Exploration Agency / Earth Observation Research Center, Tsukuba Space Center 2-1-1 Sengen, Tsukuba, Ibaraki, Japan, Tsukuba, 305-8505, Japan
AU: Nishimura, Y
EM: yns@mail.sci.hokudai.ac.jp
AF: Institute of Seismology and Volcanology, Hokkaido University, N10W8 Kita-ku, Sapporo, Hokkaido, Japan, Sapporo, 060-0810, Japan
AU: Takahashi, H
EM: hiroaki@mail.sci.hokudai.ac.jp
AF: Institute of Seismology and Volcanology, Hokkaido University, N10W8 Kita-ku, Sapporo, Hokkaido, Japan, Sapporo, 060-0810, Japan
AU: Shimada, M
EM: shimada.masanobu@jaxa.jp
AF: Japan Aerospace Exploration Agency / Earth Observation Research Center, Tsukuba Space Center 2-1-1 Sengen, Tsukuba, Ibaraki, Japan, Tsukuba, 305-8505, Japan
AB: The Japan Aerospace Exploration Agency (JAXA) launched the Advanced Land Observing Satellite (ALOS), which is commonly called eDaichif in Japanese, on 24th January 2006. This satellite has the Phased Array type L- band Synthetic Aperture Radar (PALSAR) following the mission of the Japanese Earth Resource Satellite-1 (JERS-1). The PALSAR is an advanced SAR sensor with up to 10 m of spatial resolution and variable off-nadir angle. The ALOS/PALSAR can determine the position and attitude with high accuracy by use of mounted dual frequency GPS system and high precision star trackers, and L-band SAR sensor is suitable to observe even heavily-vegetated area. Therefore it is expected much better coherent SAR images than the JERS-1 and the other previous C-band SAR satellites, and major step forward for InSAR (Interferometric SAR) technique. Actually, several outstanding results from InSAR measurements have been reported for the period after the launch. In 2007, two big earthquakes causing some damages on the periphery occurred in Japan. One is M6.7 Noto Peninsula earthquake on 25th March 2007, and the other is M6.8 off the Chuetsu region earthquake on 16th July 2007. Because both seismic faults inferred from these earthquakes are located at shallow depth beneath the bottom of the sea near the coast, obvious crustal deformation in a land area were detected by PALSAR data. In Japan, there is a dense nation-wide GPS network (GEONET) composed of more than 1200 GPS sites established and operated by Geographical Survey Institute and a lot of seismometers. Similarly GPS and seismometer could detect signals caused by the earthquakes, so these are noticeable cases from the standpoint of a comparison among various kinds of data. A remote sensing technique like the ALOS/PALSAR has advantage to observe and monitor a disaster occurred in a remote location where it is difficult to get and there has been little geophysical observation. In this presentation, we notice the case of earthquakes on 15th November 2006 in Kuril Islands and on 1st April 2007 in Solomon Islands as examples. The former earthquake (M8.3) in Kuril Islands was accompanied by tsunami and several meter of faulting. Simushir Island is situated about 200 km west of the epicenter, and has been observed by the PALSAR before and after the earthquake. Using differential InSAR technique, several fringes are detected and we presume that they show a co-seismic deformation. The latter earthquake (M8.1) in Solomon Islands was accompanied by large tsunami and caused a considerable damage in the area. The PALSAR has been observed these islands before and after the earthquake and detected an extensive co-seismic deformation areally using same technique as above. Then we try to compare these deformation to those induced from a fault model, and they show a good agreement. Compared with the amplitude image before the earthquake, several appearances of land area like uplift are recognized in the amplitude image after the earthquake. We went to the Solomon Islands in the end of July and confirmed the uplift. Additionally, we introduce a recent result of PALSAR data which targets at the M8.1 earthquake occurred in near the coast of central Peru on 15th August 2007. In the interferogram, extensive information of crustal deformation is detected.
DE: 1207 Transient deformation (6924, 7230, 7240)
DE: 1240 Satellite geodesy: results (6929, 7215, 7230, 7240)
DE: 1640 Remote sensing (1855)
DE: 7215 Earthquake source observations (1240)
DE: 7240 Subduction zones (1207, 1219, 1240)
SC: Geodesy [G]
MN: 2007 Fall Meeting