碩士 / 國立中央大學 / 地球物理研究所 / 96 / The magnitude MW = 9.3 earthquake in Sumatra-Andaman on December 26, 2004, was the second largest earthquake in the past century, rupturing along a 1200-km long reverse fault delineated by aftershocks. In this study we use the sea level change as a proxy for the regional geoid change (because the mean sea surface conforms to the geoid), focusing on the co-seismic and post-seismic behavior. For the sea level, we use the radar altimetry data form several satellites (Topex/Poseidon, Jason-1, GFO, Envisat, ERS-2) available from AVISO, from 2003 through 2006 (four years), with gridded resolution of 0.3° and time interval of seven days. We select the region of 15°N ~ 10°S and 90°E ~ 115°E. We calculate the EOF (Empirical Orthogonal Function) to analyze the space-time variation of the sea level signal before and after the Sumatra-Andaman earthquake. Besides the strongest but climate-induced mode which is highly correlated with the ENSO index, we find that the second strongest mode signifies the geoid change caused by the earthquake. This mode also shows a post-seismic recovery of the geoid on a timescale of about two years. We compare this result with recent findings from the GRACE satellite data of time-variable gravity, and confirm that both results of geoid change from pre-seismic to post-seismic are consistent.
| Identifer | oai:union.ndltd.org:TW/096NCU05134015 |
| Date | January 2008 |
| Creators | Yi-Hsiang Li, 李毅翔 |
| Contributors | Benjamin Fong Chao, 趙丰 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 73 |
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