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Geochemistry of soil gas in the seismic fault zoneproduced by the Wenchuan Ms 8.0 earthquake,southwestern China.
- Source :
- Geochemical Transactions; 2010, Vol. 11, p5-14, 10p
- Publication Year :
- 2010
-
Abstract
- The spatio-temporal variations of soil gas in the seismic fault zone produced by the 12 May 2008 Wenchuan Ms 8.0 earthquake were investigated based on the field measurements of soil gas concentrations after the main shock. Concentrations of He, H<subscript>2</subscript>, CO<subscript>2</subscript>, CH<subscript>4</subscript>, O<subscript>2</subscript>, N<subscript>2</subscript>, Rn, and Hg in soil gas were measured in the field at eight short profiles across the seismic rupture zone in June and December 2008 and July 2009. Soil-gas concentrations of more than 800 sampling sites were obtained. The data showed that the magnitudes of the He and H<subscript>2</subscript> anomalies of three surveys declined significantly with decreasing strength of the aftershocks with time. The maximum concentrations of He and H<subscript>2</subscript> (40 and 279.4 ppm, respectively) were found in three replicates at the south part of the rupture zone close to the epicenter. The spatio-temporal variations of CO<subscript>2</subscript>, Rn, and Hg concentrations differed obviously between the north and south parts of the fault zone. The maximum He and H<subscript>2</subscript> concentrations in Jun 2008 occurred near the parts of the rupture zone where vertical displacements were larger. The anomalies of He, H<subscript>2</subscript>, CO<subscript>2</subscript>, Rn, and Hg concentrations could be related to the variation in the regional stress field and the aftershock activity. [ABSTRACT FROM AUTHOR]
- Subjects :
- GEOCHEMISTRY
SOIL air
FAULT zones
EARTHQUAKE zones
SPATIO-temporal variation
HELIUM
Subjects
Details
- Language :
- English
- ISSN :
- 14674866
- Volume :
- 11
- Database :
- Complementary Index
- Journal :
- Geochemical Transactions
- Publication Type :
- Academic Journal
- Accession number :
- 57306492
- Full Text :
- https://doi.org/10.1186/1467-4866-11-5