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Seismicity and deep backgrounds of the Weihe fault depression and its adjacent areas (PDF)

《地球科学与环境学报》[ISSN:1672-6561/CN:61-1423/P]

Issue:
2004年第03期
Page:
57-60
Research Field:
Publishing date:

Info

Title:
Seismicity and deep backgrounds of the Weihe fault depression and its adjacent areas
Author(s):
WANG Wei-dong1; ZHANG Yong-zhi1; WANG Ping2; DU Chang-e2
1.School of Geological Engineering and Surveying Engineering , Chang' an University , Xi' an 710054 , China ; 2 .Seismological Bureau of Shaanxi Province , Xi' an 710068, China
Keywords:
Weihe fault depression; distribution of seismic velocity ; Q value ; seismicity
PACS:
P315.2;P315.5
DOI:
-
Abstract:
In this paper , by using the seismic data recorded from Xi' an digital telemetry seismic network and the method of half period of first P arrivals , Q value distribution of Weihe fault depression basin and its adjacent area is determined.The relationship between seismicity and Q value distribution, velocity distribution and geological structures in this region is then discussed.The results show that:1)there are two strong lateral inhomogeneous regions of Q value distribution, one is Chunhua-Yaoxian region with high Q value and its adjacent Xi' an- Fuping region and Huaxian region with low Q value , the other is Hancheng region on the boundary between Shaanxi and Shanxi Provinces with high Q value and its adjacent Cheng cheng region with low Q value .These two regions are located in a region where different tectonic units meet, and differential movement is significant and different rock strata are interceded ;2)the historical strong earthquakes occurred mainly in the transitional belt between the regions with high and low Q values;3)the distribution of Q value is comparatively consistent with the image of P-wave velocity distribution at depth h =20 km in the studied area .The above results indicate that the seismicity in this region has deep geological background and is closely related to the distribution of Q value and the image of P-wave velocity distribution of the region.

References:

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Last Update: 2004-09-20