SEISMOLOGY AND GEOLOGY ›› 2011, Vol. 33 ›› Issue (1): 157-174.DOI: 10.3969/j.issn.0253-4967.2011.01.016

• Application of new techniques • Previous Articles     Next Articles

INSAR COSEISMIC DEFORMATION OBSERVATION OF THE JAN 12TH,2010 HAITI EARTHQUAKE AND ITS COESEISMIC SLIP DISTRIBUTION INVERSION

XUE Lian1,2, SUN Jian-bao2, SHEN Zheng-kang1,2   

  1. 1. Dept of Geophysics, School of Earth and Space Sciences, Peking University, Beijing 100871, China;
    2. State Key Laboratory of Earthquake Dynamics, Institute of Geology, China Earthquake Administration, Beijing 100029, China
  • Received:2010-06-07 Revised:2011-03-08 Online:2011-04-29 Published:2011-12-18

2010年1月12日海地MW7.0地震 InSAR同震形变观测及同震滑动分布反演

薛莲1,2, 孙建宝2, 沈正康1,2   

  1. 1. 北京大学地球物理系, 北京 100871;
    2. 中国地震局地质研究所, 地震动力学国家重点实验室, 北京 100029
  • 作者简介:薛莲,女,1985年出生,2010年毕业于北京大学地球物理系,获硕士学位,现就读于加利福尼亚联合大学圣克鲁兹分校,主要研究方向为地壳形变,E-mail: xuelian.icy@gmail.com。
  • 基金资助:

    地震行业科研专项(200708002)和国家高技术研究发展计划项目(2009AA12Z1464)共同资助。

Abstract:

At 21: 53(GMT)on Jan 12th,2010,an MW 7.1 earthquake struck Haiti with epicenter located at(72.57°W,18.44°N).We derive the high precision Interferometric Synthetic Aperture Radar(InSAR)deformation field covering the whole rupture zone and use the observations to study the seismogenic kinematics of the quake.We analyze the influences of InSAR data errors,such as the orbit errors and atmospheric errors,on the ALOS PALSAR data and finally obtain the coseismic deformation field in the line of sight(LOS)direction.We invert the LOS displacement for the fault geometry of the seismogenic fault and its corresponding slip distribution.We find that the fault dips to the north at 37°,lower than the 70° north-dipping solution from USGS.To test other possible dipping angles of the fault plane and find the best estimate of the fault geometry,we construct an other two fault models.One is modeled with a 70° north-dipping fault plane and the other one is a listric fault model with the hinge depth inverted.Comparing the predicted InSAR interferogram of the three fault models with the observed InSAR coseismic data,we argue that the model with 37° north dipping angle is more rational than the other two models.Our preferred model shows that the coseismic slip concentrates mainly at 4~16km depth,and the maximum slip is 2.8m,appearing at 7.2km depth.The coseismic displacement exhibits both reversal faulting and sinistral strike-slip,suggesting complex fault motion in this earthquake.The moment release of this earthquake is 5.64×1019 Nm,equivalent to an MW 7.1 earthquake.

Key words: Haiti Earthquake, coseismic InSAR observation, coseismic slip distribution inversion

摘要:

2010年1月12日GMT时间21时53分,在海地境内(72.57°W,18.44°N)发生了MW 7.0地震。文中利用干涉合成孔径雷达(InSAR)方法获得了覆盖整个震区的高精度形变观测资料,用以研究该地震的发震机理。采用ALOS PALSAR数据,分析了轨道、大气等误差源对干涉信号的影响,最终获得了雷达视线向(LOS)的同震形变场。基于误差矫正后的InSAR同震数据,反演得到了发震断层的几何参数及断层面上的同震滑移分布。结果显示断层为N倾37°,小于USGS给出的断层倾角70°。为了测试断层倾角的最佳估计,另外建立了倾角为70°的平面断层模型,以及一种铲形断层模型。通过将不同模型预测的InSAR干涉图和InSAR同震观测数据对比,认为倾角为37°的断层模型更为合理。断层同震滑动主要分布在4~16km深度范围内,最大同震滑移量达2.8m,深度为7.2km。滑动主要表现为逆冲兼具左旋走滑2种方式,显示了此次地震非常复杂的运动特点。据此模型得到该地震释放的地震矩为5.64×1019 Nm,对应矩震级为MW 7.1。

关键词: 海地地震, InSAR同震观测, 同震滑动分布反演

CLC Number: