[1]ZHANG Xi,CUI Du-xin,WANG Wen-ping,et al.Using GPS Data to Analyze Horizontal Movement and Strain Accumulation in Sichuan-Yunnan and Its Vicinity before and after the Wenchuan Earthquake[J].Journal of Seismological Research,2008,31(增刊):464-470.
Copy
Journal of Seismological Research[ISSN 1000-0666/CN 53-1062/P] Volume:
31
Number of periods:
2008 05
Page number:
464-470
Column:
Public date:
2008-11-23
- Title:
-
Using GPS Data to Analyze Horizontal Movement and Strain Accumulation in Sichuan-Yunnan and Its Vicinity before and after the Wenchuan Earthquake
- Author(s):
-
ZHANG Xi; CUI Du-xin; WANG Wen-ping; JIANG Feng-yun
-
(The Second Monitoring and Application Center,CEA,Xi'an 710054,Shaanxi,China)
-
- Keywords:
-
Wenchuan MS8.0 earthquake; GPS; deformation-strain field; negative dislocation; coseismic deformation
- CLC:
-
P315.2
- DOI:
-
-
- Abstract:
-
Based on the horizontal velocity data observed by GPS during 2004-2008,i.e., before and after the Wenchuan MS8.0 earthquake,in Sihcuan-Yunnan and its vicinity(the southeastern Gansu and the part of Shaanxi),we study the preseismic tectonic deformation features and strain accumulation background,the coseismic deformation and its possible influence area combining with the analysis on the features of evolution of deformation-strain field and the inversion of negative dislocation. We conclude:(1)In the period of 2004-2007,obvious compression change and the phased feature of strain accumulation appeared in the two sides of the central Longmenshan fracture,which revealed the Wenchuan earthquake to a certain extent(it may be the medium-term background information of MS≥6.0 earthquake). The north-northeast boundary,the middle-west segment of south boundary of the Sichuan-Yunnan rhombus block probably had the background of MS≥6.0 earthquake preparation. The south-southwestern Yunnan,the area from the east segment of Gansu-Sichuan boundary to Gansu-Sichuan-Shaanxi boundary,and the southern Gansu block reflected the seismogenic information of the earthquake with magnitude about 6.0.(2)In the period of August 2007-June 2008,the Wenchuan earthquake area showed remarkable coseismic thrust and dextral deformation. The effect of the Wenchuan earthquake was comparatively obvious on the strain accumulation of Gansu-Sichuan boundary,Gansu-Sichuan-Shaanxi boundary,the south segment of Xianshuihe fracture and the Y-shape intersection region of fractures,which is possibly shown as a certain increase.