碩士 / 國立中山大學 / 海下科技研究所 / 107 / Earthquake happens frequently in Taiwan and its surrounding. Although there are many land stations, the offshore observation are limited to few isles, like Turtle island and Green island. Expanding the instant observation network to the sea improves the accuracy of computed hypocenter and shortens the response time, but quite costly. The technique of autonomous observation for offshore earthquake is more feasible budgetwise. The Ocean-Buttom Seismometer (OBS) can be applied to record earthquake activity on the seabed and analyze with data from land stations. However, there are many ambient noise in the ocean. Especially when the infragravity wave happens, signal of seismic wave of Rayleigh wave recorded by OBS can be significantly affected. In order to remove the noise, OBS is deployed together with DPG, which can detect low frequency and small pressure. By data processing, we can remove infragravity wave signal from vertical component of OBS and improve the accuracy of computed hypocenter. Xiang-Rong Luo, a master student from Institute of Underwater Technology in National Sun Yat-sen University, designed a testing mechanism, which can test whether DPG can detect infragravity wave. But at the beginning of design, no phase angle was provided. We improve the testing mechanism by equipping encoder. Converting angle change into induced pressure help calculate the phase angle. And we find that atmosphere pressure change will affect the phase angle. So we seal the environment to provide better phase angle and complete this calibration method.
| Identifer | oai:union.ndltd.org:TW/107NSYS5281003 |
| Date | January 2018 |
| Creators | Huang-Chi Chang, 張煌琪 |
| Contributors | Chau-Chang Wang, 王兆璋 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 66 |
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