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GPS观测结果反映的尼泊尔Mw7.8地震孕震特征

DOI: 10.6038/cjg20150532, PP. 1818-1826

Keywords: 孕震模式,尼泊尔地震,速度场融合,GPS应变率场,同震位移场

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Abstract:

针对2015年4月25日尼泊尔Mw7.8地震的孕震特征,本文首先对覆盖尼泊尔及周边地区的5套GPS水平速度场结果进行了融合,得到了近似统一参考框架下的速度场结果;在此基础上通过对此次地震震源区及周边地区的速度场、应变率场、基线时间序列分析,识别了震前变形特征.GPS应变率场结果显示,喜马拉雅主边界断裂存在大范围挤压应变积累,震源区处于近南北向应变积累高值过渡区.跨喜马拉雅构造带的GPS基线时间序列结果表现为持续缩短现象,表明印度板块与欧亚板块之间的持续挤压变形特征,2012年以来的缩短增强现象反映了印度板块对青藏块体的推挤增强作用明显.距离震中较近的西藏南部GPS同震位移结果以南向运动为主且指向震中,反映了青藏高原存在逆冲应变释放现象.综合此次尼泊尔地震前变形和同震应变释放特征,认为此次地震的孕震区域和同震应变释放区域均较大,将会对青藏高原的地壳变形与强震孕育产生深远影响.

References

[1]  Ader T, Avouac J P, Jing L Z, et al. 2012. Convergence rate across the Nepal Himalaya and interseismic coupling on the Main Himalayan Thrust: Implications for seismic hazard. Journal of Geophysical Research, 117, B04403, doi: 10.1029/2011JB009071.
[2]  Bettinelli P, Avouac J P, Flouzat M, et al. 2006. Plate motion of India and interseismic strain in the Nepal Himalaya from GPS and DORIS measurements. Journal of Geodesy, 80(8-11): 567-589.
[3]  Deng Q D, Cheng S P, Ma J, et al. 2014. Seismic activities and earthquake potential in the Tibetan Plateau. Chinese Journal of Geophysics (in Chinese), 57(7): 2025-2042, doi: 10.6038/cjg20140701.
[4]  USGS,2015.M7.8-34 km ESE of Lamjung, Nepal,http://earthquake.usgs.gov/earthquakes/eventpage/us20002926[2015-05-.
[5]  Ward S N. 1994. A multidisciplinary approach to seismic hazard in southern California. Bulletin of the Seismological Society of America, 84(5): 1293-1309.
[6]  Wang Q, You X Z, Wang W Y, et al. 1998. GPS measurement and current crustal movement across the Himalaya. Crustal Deformation and Earthquake (in Chinese), 18(3): 43-50.
[7]  Wang Q, Zhang P Z, Freymueller J T, et al. 2001. Present-day crustal deformation in China constrained by global positioning system measurements. Science, 294(5542): 574-577.
[8]  Wu Y Q, Jiang Z S, Yang G H, et al. 2011. Comparison of GPS strain rate computing methods and their reliability. Geophysical Journal International, 185(2): 703-717, doi: 10.1111/j.1365-246X. 2011.04976.x.
[9]  Wu Y Q, Jiang Z S, Yang G H, et al. 2009. The application and method of GPS strain calculation in whole mode using square collocation in sphere surface. Chinese J. Geophys. (in Chinese), 52(7): 1707-1711, doi: 10.3969.issn.00015733.
[10]  Wu Y Q, Jiang Z S, Zhao J, et al. 2015. Crustal deformation before the 2008 Wenchuan Ms8.0 earthquake studied using GPS data. Journal of Geodynamics, 85: 11-23.
[11]  Xiao G R.2011.GPS crustal deformation observations and its application in the great triangular seismotectonic[Ph.D.thesis](in Chinese). Beijing:Institute of Geology, China Earthquake Administration.
[12]  Zhang P Z, Deng Q D, Zhang G M, et al. 2003. Active-tectonic blocks and strong earthquakes in the continent of China. Science in China (Series D), 46(S2): 13-24.
[13]  Bilham R, Larson K, Freymueller J. 1997. GPS measurements of present-day convergence across the Nepal Himalaya. Nature, 386(6620): 61-64.
[14]  Chen G Q, Wu Y Q, Jiang Z S, et al. 2013. Characteristics of seismogenic model of Mw9.0 earthquake in Tohoku, Japan reflected by GPS data. Chinese J. Geophys. (in Chinese), 53(5): 848-856, doi: 10.6038/cjg20130314.
[15]  Chen Q Z, Freymueller J T, Wang Q, et al. 2004. A deforming block model for the present-day tectonic of Tibet. Journal of Geophysical Research, 109 : B01403, doi: 10.1029/2002JB002151.
[16]  China Earthquake Administration. 2015. 《The atlas of Mw7.8 earthquake in Nepal occurred on April 25, 2015》. http://eqxiu.com/s/LXU4nA8y?eqrconde=1[2015-5-.
[17]  Feldl N, Bilham R. 2006. Great Himalayan earthquakes and the Tibetan plateau. Nature, 444(7116): 165-170.
[18]  Gan W J, Zhang P Z, Shen Z K, et al. 2007. Present-day crustal motion within the Tibetan Plateau inferred from GPS measurements. Journal of Geophysical Research, 112 : B08426, doi: 10.1029/2005JB004120.
[19]  Institute of Geophysics, China Earthquake Administration. 2015. 《The Mw7.8 earthquake in Nepal occurred on April 25, 2015》. http://www.cea-igp.ac.cn/tpxw/272110.shtml[2015-3-.
[20]  Jiang Z S, Fang Y, Wu Y Q, et al. 2009. The dynamic process of regional crustal movement and deformation before Wenchuan Ms8.0 earthquake. Chinese J. Geophys. (in Chinese), 52(2): 505-518.
[21]  Jiang Z S, Liu J N. 2010. The method in establishing strain field and velocity field of crustal movement using least squares collocation. Chinese J. Geophys. (in Chinese), 53(5): 1109-1117, doi: 10.3969/j.issn.0001-5733.2010.05.011.
[22]  Liang S M, Gan W J, Shen C Z, et al. 2013. Three-dimensional velocity field of present-day crustal motion of the Tibetan Plateau derived from GPS measurements. Journal of Geophysical Research: Solid Earth, 118, doi: 10.1002/2013JB010503.
[23]  Ponraj M, Miura S, Reddy C D, et al. 2010. Estimation of strain distribution using GPS measurements in the Kumaun region of Lesser Himalaya. Journal of Asian Earth Science, 39(6): 658-667.

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