本研究利用疊前逆時深度移位處理地質複雜地區的長支距多頻道震測資料。此技術已經被地球物理家們發展了數十年，是利用波動方程式的數值模擬法，使接收到的震波資料直接由接收位置逆時傳播到反射點，該點的成像時間，是震波由震源到該點的單向旅行時間，此運算法能適用於地質複雜區域的資料處理。但是其龐大的運算量使過去地球物理家們無法將此技術商業化，直到現在電腦計算速度已大幅增加，使我可以用自行編寫的程式去做此研究。本研究所處理的是台灣西南海域收集的震測資料，此區域在地體上屬於弧前盆地，具有複雜的地質構造。從結果來看，疊前逆時深度移位比起現在較常用的疊前Kirchhoff移位有品質更好的移位影像，在Kirchhoff影像中的地層交叉情形，在逆時深度移位影像中則大量減少。這顯示在不久的未來，疊前逆時深度移位有很高的可能性取代疊前Kirchhoff移位。

This research is an experiment that uses prestack reverse-time depth migration to process the long-offset multichannel seismic data acquired in a geologically complex area. Geophysicists have been developing reverse-time depth migration for decades. Reverse-time depth migration uses numerical simulation of wave equation in reverse-time order to drive recorded seismic data directly from the receiver locations to the reflectors, and takes the imaging time at a point as the one-way travel time from the source to that point. Reverse-time depth migration has long been considered as an excellent algorithm for handling seismic data acquired in geologically complex area. But geophysicists have commercially applied reverse-time depth migration until recently because of the mass computation load that was not affordable to computers in the past. The current computers are fast enough so that I can perform reverse-time depth migration experiments using self-coded programs. The seismic data were acquired in offshore southwestern Taiwan where the geological complex fore-arc basin. The results show that quality of the migrated images of prestack reverse-time depth migration is much better than that of prestack Kirchhoff depth migration, which is currently the most widely used algorithm. Lots of the artifacts that appear in Kirchhoff migration images disappear in reverse-time migration images. This result shows that prestack reverse-time migration has the high potential of replacing prestack Kirchhoff migration in the near future.

Chuang, P., Yang, T., Lin, S., Lee, H., Lan, T., Hong, W., Liu, C., Chen, J. and Wang, Y., Extremely high methane concentration in bottom water and cored sediments from offshore southwestern Taiwan. Terrestrial Atmospheric and Oceanic Sciences, 17, 903-920, 2006.
Hokstad, K. Multicomponent Kirchhoff migration. Geophysics, 65, 861-873, 2000.
Liu, C.-S., Lundberg, N., Reed, D. L. and Huang, Y.-L., Morphological and seismic characteristics of the Kaoping submarine canyon. Marine Geology, 111, 93-108, 1993.
Liu, C.-S., Huang, I.-L. and Teng, L. S., Structural features off southwestern Taiwan. Marine Geology, 137, 305-319, 1997.
Liu, C., Schnürle, P., Wang, Y., Chung, S., Chen, S. and Hsiuan, T., Distribution and characters of gas hydrate offshore of southwestern Taiwan. Terrestrial Atmospheric and Oceanic Sciences, 17, 615-644, 2006.
Reed, D. L., Lundberg, N. Liu, C.-S. and Kuo, B.-Y., Structural relations along the margins of the offshore Taiwan accretionary wedge; implication for accretion and crustal kinematics. Acta Geologica Taiwanica, 30, 105-122, 1992.
Sun, R. and McMechan, G.A., Pre-Stack reverse-time migration for elastic waves with application to synthetic offset vertical seismic profiles, Proceedings of the IEEE, 74, 457-563, 1986.
Sun, S.-C. and Liu, C.-S., Mud diapirs and submarine channel deposits in offshore Kaohsiung-Hengchun, southwest Taiwan. Petrol. Geol. Taiwan, 28, 1-14, 1993.
Sun, R. and McMechan, G. A., Scalar reverse-time depth migration of elastic seismic data, Geophysics, 66, 1515-1518, 2001.
Sun, R. , McMechan, G.A., Lee, C. S., Chow, J. and Chen, C. H., Prestack scalar reverse-time depth migration of three-dimensional elastic seismic data, Geophysics, 71, 5, S199–S207, 2006.
Whitmore, N. D., Iterative depth migration by backward time propagation, 53rd Annual International Meeting, SEG, Expanded Abstracts, 382-385 , 1983.
Yang, K. M., Ting, H. H., and Yuan, J., Structural styles and tectonic modes of Neogene extensional tectonics in southwestern Taiwan: implications for hydrocarbon exploration. Petrol. Geol. Taiwan, 26, 1-31, 1991.
Yu, H.-S. and Lee, J. T., The multi-head Penghu submarine canyon off southwestern Taiwan: Morphology and orgin. Acta Oceanogr. Taiwanica, 30, 10-21, 1993.
Yu, H.-S. and Lu, J.-C., Development of the shale diapir-controlled Fangliao Canyon on the continental slope off southwestern Taiwan. Jour. Southeast Asian Earth Sci., 11, 265-276, 1995.
Yu, H.-S. and Chiang, C.-S., Seismic and morphological characteristics of the Kaohsiung Submarine Canyon, southwestern Taiwan, Journal of Geological Society of China, 39, 73-86, 1996.
Yu, H.-S. and Huang, E.- C., Morphology and origin of the Shoushan submarine canyon off southwest Taiwan. Jour. Geol. Soc. China, 41, 565-579, 1998.
牟永光、陳小宏、劉洋、李國發、王守東，地震數據處理方法，石油工業出版社，北京，1-184，2007。
林哲銓，台灣西南海域含天然氣水合物地層之構造架構與沈積特徵，國立中央大學地球物理研究所碩士論文，2005。
張文生，波動方程式成像方法及其計算，科學出版社，北京，1-129，2009。
張成華，臺灣西南部海域泥貫入體研究，國立臺灣大學海洋研究所碩士論文，1993。
熊章強、周竹生、張大洲，地震勘探，中南大學出版社，長沙，180-250，2010。
羅聖宗，台灣周邊海域天然氣水合物調查研究先期規劃研究成果報告，經濟部中央地質調查所，2001。