首頁瀏覽人次: 697,148 次 (Since 2010/07/14) 會員登入
聯盟單位  |  虛擬講堂  |  網路直播  |  其他演講  |  排行榜  |  留言板  |  知識擂台  |  回首頁
首頁 > 虛擬講堂 > 隱沒帶大地震之前世今生與來生 快速搜尋演講 進階搜尋
  隱沒帶大地震之前世今生與來生 
★chrome瀏覽器無法播放Silverlight解決辦法
0:00 / 0:00

講者:許雅儒 中央研究院地球科學研究所 副研究員
日期:2013/11/22
性質:演講
類別:應用科學、教育學習
語言:中文
長度:00:38:23
觀看:1,067
推薦:1
摘要:

Subduction zone earthquakes result from the plate convergence between two plates. The strain is built up on the fault along the plate...

Subduction zone earthquakes result from the plate convergence between two plates. The strain is built up on the fault along the plate interface and in areas near the plate margin. If the fault is locked over some width, the horizontal shortening and uplifting can be observed on the overriding plate before occurrences of great earthquakes. There are several ways to release accumulated strain, for instances, large earthquakes, slow earthquakes, transient slip events, or fault creep after large earthquakes.
The subduction zone earthquake cycle can be viewed as a combination of interseismic, coseismic and postseismic periods. Using geodetic data before occurrences of large earthquakes (interseismic period), the spatial extent of the deformation, the width and location of locked fault, and the fault geometry can be estimated. During an earthquake rupture (coseismic period), the accumulated strain of locked fault is released and resulting coseismic subsidence and horizontal extension in the region where show uplift and horizontal shortening in the interseismic period. The stress perturbation due to the mainshock would result in postseismic creep on the ruptured fault, or transient slip on nearby fault systems, or viscoelastic relaxation of the lower crust and upper mantle in the postseismic period.
The focus of this talk on a series of earthquakes after the December 26, 2004 Mw 9.1 Aceh-Andaman earthquake, occurred on the subduction megathrust offshore northwestern Sumatra, In this region, the Indo-Australian plate converges obliquely towards the Sunda Block, at a rate of about 57 mm/yr. This convergence is approximately partitioned into a 40 mm/yr trench-normal component on the megathrust and a 25 mm/yr component of dextral slip along the Sumatran Fault. The subduction megathrust offshore Sumatra has produced 4 earthquakes with magnitudes larger than 8 since 1797, including a M8.5 event near Nias in 1861 that occurred in the approximate region of the southern asperity of the 2005 Mw 8.7 Nias-Simeulue earthquake. Using paleogeodetic and recent continuous Global Positioning System data from the Sumatran Geodetic Array as well as survey-mode GPS data, we study fault slip behaviors along the Sunda megathrust. A heterogeneous coupling pattern in the interseismic period is revealed. The correlation of locked fault patches during the interseismic period and large seismic asperities suggests that they are persistent features. The geomorphologic features, subducting seafloor roughness, the thickness of sediments, temperature, as well as some other factors may affect the spatial extent of great subduction zone ruptures.
備註:本演講內容只提供教育使用,不可涉及任何形式商業行為


現在位置:演講摘要詳細內容
推薦  (1)
推薦至Plurk
提供:國立自然科學博物館-「從車籠埔斷層看過去現在與未來的地震」國際學術研討會

轉寄  

推薦者:
電子郵件地址: (如欲轉寄多人,請以 ; 分隔email)
留言給收件者:

回報問題  

問題說明:




106年10月份知識饗宴「隱...
講者:許雅儒
觀看:237
【週日閱讀科學大師】龍貓森林...
講者:余建勳
觀看:1,364
潛進歷史 - 到水下考古去
講者:臧振華
觀看:1,247
人工智慧取代醫師的時代?
講者:唐高駿
觀看:537
【週日閱讀科學大師】通往宇宙...
講者:吳俊輝
觀看:79
【週日閱讀科學大師】上太空也...
講者:黃居正
觀看:74

現在位置:學習公約