研究生: |
陳耀傑 Chen, Yao-Chieh |
---|---|
論文名稱: |
利用台灣東部重複地震推估斷層滑移速率 Fault Slip Rate Inferred from Repeating Earthquakes in Eastern Taiwan |
指導教授: |
陳卉瑄
Chen, Hui-Hsuan |
學位類別: |
碩士 Master |
系所名稱: |
地球科學系 Department of Earth Sciences |
論文出版年: | 2017 |
畢業學年度: | 105 |
語文別: | 中文 |
論文頁數: | 89 |
中文關鍵詞: | 重複地震 、東部縱谷斷層 、深部滑移速率 、週期性波動 、成功地震 |
英文關鍵詞: | repeating earthquake, LVF, deep slip rate, periodic pulsing, Chengkung earthquake |
DOI URL: | https://doi.org/10.6345/NTNU202202821 |
論文種類: | 學術論文 |
相關次數: | 點閱:126 下載:10 |
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本研究首先以張育群(2013)所提出之台灣重複地震自動化偵測系統,建立全 台灣 2000 至 2011 年底規模 2 以上相似地震目錄,再進一步活動性最高的東部縱谷 斷層區域,建立生命週期大於 3 年之東部重複地震目錄,共 405 個序列。縱谷區域 重複地震在最南段集中於台東一帶共有 6 個序列,深度分佈為 5~30 公里;池上地 區共有 94 個序列、深度分佈為 4~30 公里;在玉里一帶,僅有 16 個重複地震序列 分佈,並於深度上呈現近乎垂直之分佈,深度集中於 8~20 公里;而北至花蓮一帶 呈現兩群東北–西南走向的重複地震群,分別發生在海岸山脈和中央山脈東翼下方, 總共有 184 個序列、深度在 5~37 公里。
根據其週期性之不同,利用復發週期之變異係數(coefficient of variance, COV) 0.3 為門檻值,將序列分為準週期性(Q-type, COV < 0.3)以及非週期性(A-type, COV > 0.3)序列,再根據非週期性序列對於大地震之反應不同,再細分為:受影響序列 (I-type,於鄰近大地震之後復發週期減少),以及新序列(N-type,該序列中第一 個事件發生於成功地震以後)兩種;並發現該兩種序列皆受 2003 年 12 月 10 日成功 地震影響,並僅分佈於池上一代,隨後利用前人之經驗公式推算各種序列之正規化 滑移速率後,發現準週期性序列之平均滑移速率於主震前後近乎一致,而其餘兩種 序列分別受到不同程度的影響。
除時間特徵外,以重複地震序列於空間上集中程度,可細部分區為花蓮東側 (HE)、西側(HW);池上北段(CN)、中段(CM)、以及南段(CS),利用移動 視窗平均計算區域滑移速率,我們發現 CN 以及 CM 皆受成功地震影響,於震後滑 移速率上升,震前的滑移速率分別為 1.4 和 2.09 cm/yr。不受大地震影響的 HE、HW 和 CS 其深部滑移速率則分別為 3.13、5.63 和 1.29 cm/yr。將這些數值和大地測量資 料所推估之斷層滑移速率相比,我們發現:池上地區重複地震集中於北段,並且深 部滑移速率與地表變形速率相比具有約 1 cm/yr 之盈虧,顯示可能於南段或較淺部 鎖定;玉里地區具有高深部滑移速率(4.96 cm/yr ),且重複地震分佈集中,可能於 某處具有無震滑移;花蓮東側和地表觀測結果相似,然西側位於中央山脈底下,其 高滑移速率亦高達 4.96 cm/yr,然無地表資料可供比對分析,其孕震機制及位置仍 尚待討論。
Creeping crustal faults often generate streaks of microearthquakes, but less commonly, they may still produce large earthquakes that rupture the brittle crust. The 150-km-long Longitudinal Valley Fault (LVF) in eastern Taiwan, characterized by ~ 1-3 cm/yr surface slip rate, is one of the best examples in the world that possesses earthquake potential in creeping segments. Built on the 2000-2011 earthquake catalog, we identified 405 M > 2 repeating earthquake sequences (RES) along the LVF and studied the recurrence property of the repeating earthquakes. The population of RES and the inferred deep slip rate revealed that: (1) the southern Chihshang area is locked in the southern half and creeping in the north with a deep slip rate of 1.4-1.5cm/yr at the depth of 10-25 km. The deep slip rate in southern half of the Chihshang fault was accelerated by the 2003 M6 ChengKung earthquake from inter-seismic rate of 1.92 cm/yr to 4.94 cm/yr; (2) the Yuli segment in the middle of the LVF is mainly locked but partially creeping in a narrow area with deep slip rate of 4.96 cm/yr at the depth of 10-20 km; (3) the Hualien segment reveals two fault strands, one beneath the coastline (likely the Meilun fault) that is characterized by ~2 cm/yr deep slip rate (similar to surface slip rate), the other underneath the Central Range with ~80 km spatial extent in the mapview and its deep slip rate of 4.96 cm/yr indicate a significant fast-slip fault motion that has been long neglected.
Aki, K. (1966). Generation and propagation of G waves from the Niigata earthquake of June 16, 1964. 2. Estimation of earthquake moment, release energy, and stress-strain drop from G wave spectrum, Bull. Earthquake Res. Institute 44, 23-88.
Beeler, N. M., S. H. Hickman, and T. Wong (2001), Earthquake stress drop and laboratory-inferred interseismic strength recovery, J. Geophys. Res., 106(B12), 30701–30713, doi:10.1029/2000JB900242.
Chen, K. H., Nadeau, R. M., and Rau, R. J. (2008), Characteristic repeating microearthquakes on an arc-continent collision boundary - the Chihshang fault of eastern Taiwan, Earth Planet. Sci. Lett., 276, doi:10.1016/j.epsl.2008.09.021.
Chen, K. H., Rau, R. J., and Hu, J. C. (2009), Variability of the repeating earthquakes behavior along the Longitudinal Valley fault zone of eastern Taiwan, J. Geophys. Res., 114, B05306, doi:10.1029/2007JB005518.
Chen, K. H., R. Burgmann, R. M. Nadeau, T. Chen, and N. Lapusta (2010), Postseismic variations in seismic moment and recurrence interval of repeating earthquakes, Earth Planet. Sci. Lett., 299, 118–125.
Hanks, T. C., and H. Kanamori (1979), A moment magnitude scale, J. Geophys. Res., 84(B5), 2348–2350, doi:10.1029/JB084iB05p02348.
Huang, K.C., Kao, H., Wu, Y.M., 2000. The determination of ML–MW in Taiwan, 8th Annual Meeting of Geophysical Society of China, pp. 193–201. in Chinese.
Igarashi, T., T. Matsuzawa, and A. Hasegawa (2003), Repeating earthquakes and interplate aseismic slip in the northeastern Japan subduction zone, J. Geophys. Res., 108(B5), 2249, doi:10.1029/2002JB001920.
Johnson, L. R., and R. M. Nadeau (2002), Asperity model of an earthquake: Static problem, Bull. Seismol. Soc. Am., 92, 672–686.
Kuochen, H., Y. M. Wu, C. H. Chang, J. C. Hu, and W. S. Chen (2004), Relocation of eastern Taiwan earthquakes and tectonic implications, Terr. Atmos. Oceanic Sci., 15, 647–666.
L Bollinger, F Perrier, J.-P Avouac, S Sapkota, U Gautam, et al.. Seasonal modulation of
87
seismicity in the Himalaya of Nepal. Geophysical Research Letters, American
Geophysical Union, 2007, 34 (8), pp.L08304. .
Marone, C., J. E. Vidale, W. L. Ellsworth (1995), Fault healing inferred from time
dependent variations in source properties of repeating earthquakes, Geophys. Res.
Lett., 22, 3095–3098.
Nadeau, R. M., and L. R. Johnson (1998), Seismological studies at Parkfield VI: Moment
release rates and estimates of source parameters for small repeating earthquakes, Bull.
Seismol. Soc. Am., 88, 790– 814.
Nadeau, R.M., McEvilly, T.V. (1999). Fault slip rates at depth from recurrence intervals
of repeating microearthquakes. Science 285, 718–721.
Nadeau, R.M., McEvilly, T.V. (2004), Periodic pulsing of characteristic
micro-earthquakes on the San Andreas fault. Science 303, 220–222.
Nadeau, R.M., Foxall, W., McEvilly, T.V. (1995), Clustering and periodic recurrence of microearthquakes on the San Andreas fault at Parkfield, California. Science 267,
503–507.
Poupinet, G., W. L. Ellsworth, and J. Fre ́chet (1984), Monitoring velocity variations in
the crust using earthquake doublets: an application to the Calaveras fault, California,
J. Geophys. Res. 89, 5719–5731.
Schaff, D.P. and Beroza, G.C. (2004), Coseismic and postseismic velocity changes
measured by repeating earthquakes, J. Geophys. Res. 109, B10302,
doi:10.1029/2004JB003011.
Uchida, N., Iinuma, T., Nadeau, R. M., Bürgmann, R., & Hino, R. (2016). Periodic slow
slip triggers megathrust zone earthquakes in northeastern Japan. Science, 351(6272),
488-492.
Uchida, N., Shimamura, K., Matsuzawa, T., & Okada, T. (2015). Postseismic response of
repeating earthquakes around the 2011 Tohoku‐oki earthquake: Moment increases due to the fast loading rate. Journal of Geophysical Research: Solid Earth, 120(1), 259-274.
Vidale, J. E., W. L. Ellsworth, A. Cole, and C. Marone (1994), Variations in rupture process with recurrence interval in a repeated small earthquake, Nature, 368, 624– 626.
88
Yu, S.B., Kuo, L.C., 2001. Present-day crustal motion along the Longitudinal Valley Fault, eastern Taiwan. Tectonophysics 333, 199–217.
Working Group on California Earthquake Probabilities (1995). Seismic hazards in southern California: probable earthquakes, 1994 to 2024, Bull. Seism. Sac. Am. 85, 379-439.
Wu, Y. M., Chang, C. H., Zhao, L., Teng, T. L., & Nakamura, M. (2008). A comprehensive relocation of earthquakes in Taiwan from 1991 to 2005. Bulletin of the Seismological Society of America, 98(3), 1471-1481.
張育群,2013,建置台灣重複地震自動化偵測系統,國立台灣師範大學地球科學系 碩士論文,共 175 頁。
陳文山、林益正、顏一勤、楊志成、紀權窅、黃能偉⋯盧詩丁 (2008) 從古地震研 究與 GPS 資料探討縱谷斷層的分段意義。 經濟部中央地質調查所彚刊,第 20 號,165~191。