Geoelectric signals in China and the earthquake generation process

	Geoelectric signals in China and the earthquake generation process
	Chu, JJ ; Gui, XT ; Dai, JA ; Marone, C ; Spiegelman, MW ; Seeber, L ; Armbruster, JG
刊名	JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
	1996-06-10
卷号	101 期号:B6 页码:13869-13882
ISSN号	2169-9313
文献子类	Article
英文摘要	We present original apparent resistivity records for stations located in the Chinese provinces of Hebei and Sichuan, along with seismicity patterns, fault maps, and limited hydrologic data These records are part of a 30-year database of geoelectric signals that have been recorded in China by a nationwide network of more than 100 stations set up by the State Seismological Bureau of the People's Republic of China The database includes the time period during which the M 7.8 1976 Tangshan and M 7.2 1976 Songpan earthquakes occurred. Resistivity data recorded in and around the epicentral region of the Tangshan event show coherent changes, both temporal and in areal distribution, years and months before and after the earthquakes. A regional change in water table occurred more than 3 years prior to the Tangshan earthquake. The resistivity and water table signals appear to correlate in the 2- to 3-year period prior to the earthquake. Rainfall records from the region around Tangshan, extending to the cities of Beijing and Tianjin, do not appear: to account for the resistivity changes. Regional seismicity and active fault patterns in north China indicate that deformation occurs mainly along the borders of large tectonic blocks. The source region for the geoelectric signals appears to lie within a large shear zone, at the edge of a tectonic block undergoing rotation. The Tangshan epicentral area is thus only part of a larger zone of deformation. We suggest that dilational strain associated with the opening of fractures may lower resistivity and water table, For shallow crustal depths, such as those monitored by the Chinese geoelectric network, dilation and resistivity changes are expected to begin at stress levels well below the peak values of the seismic cycle. Our study suggests that in some cases the areal extent of geoelectric signals may be significantly larger than that of the eventual earthquake source dimension. The Chinese geoelectric database offers an opportunity to improve our understanding of possible geoelectric precursors to earthquakes.
WOS关键词	MAGNETIC-FIELD MEASUREMENTS ; SAN-ANDREAS FAULT ; CALIFORNIA ; RESISTIVITY ; PRECURSORS ; PARKFIELD ; SEISMICITY ; PREDICTION ; TECTONICS ; EVOLUTION
WOS研究方向	Geochemistry & Geophysics
语种	英语
出版者	AMER GEOPHYSICAL UNION
WOS记录号	WOS:A1996UQ01400022
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/74890]
专题	中国科学院地质与地球物理研究所
作者单位	1.MIT, DEPT EARTH ATMOSPHER & PLANETARY SCI, CAMBRIDGE, MA 02139 USA 2.COLUMBIA UNIV, LAMONT DOHERTY EARTH OBSERV, PALISADES, NY 10964 USA 3.STATE SEISMOL BUR, CTR ANAL & PREDICT, BEIJING 100036, PEOPLES R CHINA 4.ACAD SINICA, INST GEOL, BEIJING 100029, PEOPLES R CHINA
推荐引用方式 GB/T 7714	Chu, JJ,Gui, XT,Dai, JA,et al. Geoelectric signals in China and the earthquake generation process[J]. JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH,1996,101(B6):13869-13882.
APA	Chu, JJ.,Gui, XT.,Dai, JA.,Marone, C.,Spiegelman, MW.,...&Armbruster, JG.(1996).Geoelectric signals in China and the earthquake generation process.JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH,101(B6),13869-13882.
MLA	Chu, JJ,et al."Geoelectric signals in China and the earthquake generation process".JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH 101.B6(1996):13869-13882.