碩士 / 國立中山大學 / 海下科技研究所 / 104 / There were catastropic losses in Asia by undersea earthquakes and related tsunamis, for example, Indonesion trsunami of 2004 and Miyagi earthquake of Japan in 2011. Taiwan is on the border of the Eurasian and the Philippine Sea tectonic plates, so severe earthquakes are frequent. According to the statistics by Center Weather Bureau （CWB）, more than 22,000 earthquakes occurred each year during 2001 through 2012, approximat seventy percent of them were in eastern sea of Taiwan, so the station on land can’t offer enough information. In order to improve the capability of offshore earthquakes monitoring, this research used on hydrophone’s data of MACHO（Marine Cable Hosted Observatory）, which was built in the northeastern sea of Taiwan in 2011, and epicenter, depth, Richter scale, and occurring time of earthquake measured by CWB to study undersea earthquake noise and its inversion of earthquake scale. Noise by each earthquake was analyzed in 16 Hz octave band to obtain the Sound Pressure Level（SPL）. Because the earthquakes of this study occurred in a concentrated region, so the noise level had low correlation with depth and distance of earthquake. Initial noise inversion was based on earthquake scale only. By observing the noise spectrogram, the noise made by S wave would change with the incident angle where earthquake wave into seabed. The incident angle is formed by depth and distance of earthquake, which was added to inversion formula by regression analysis of level compulsion due to different incident angle. By other earthquake data, final the inversion formula is proved to be more accurate in earthquake scale estimation, which support the usefulness of the result of this research.
| Identifer | oai:union.ndltd.org:TW/104NSYS5281005 |
| Date | January 2016 |
| Creators | Xiao-hua Wang, 王孝驊 |
| Contributors | Ruey-Chang Wei, 魏瑞昌 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 50 |
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