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利用“中国地壳运动观测网络(二期)”245个GPS连续观测站及其他站的大量观测结果,采用离震中很远的7个GPS站作为位错参考框架,得到2011年3月11日东日本Mw9.0大地震的同震水平位移和应变。此种参考框架的位移场解,符合弹性位错模型离震中很远且水平位移接近于0的要求,不仅有利于位错模型反演,也有利于合理分析此次大地震同震水平位移的影响范围。地震前后区域参考框架下远场GPS连续观测位移时间序列和同震位移弹性位错模型反演结果表明,东日本大地震同震水平位移既是地震断层破裂的结果,也是远场震前数月或数年水平位移的弹性回跳,据此可以进一步确认这些站震前水平位移前兆异常。由于这些震前异常位移中亦包含了同震位移量(方向相反),因此,弹性位错模型为定量研究大地震前远场地壳运动异常提供了一种理论模型。位错参考框架中的同震位移及其位错模型和区域参考框架的位移时间系列的综合研究有助于对此次大地震地壳运动异常的认识。这种持续时间为数月至数年的弹性形变异常,可以为大地震的中短期预测提供依据。
Based on a large number of observations from 245 GPS continuous observatories and other stations, using 7 GPS stations far away from the epicenter as the dislocation reference frame, Coseismic Horizontal Displacement and Strain of East Japan Japan Mw9.0 Earthquake. The displacement field solution of such a reference frame meets the requirement that the elastic dislocation model is far away from the epicenter and the horizontal displacement is close to zero, which is not only beneficial to the inversion of dislocation models, but also conducive to a reasonable analysis of the horizontal displacement of coseismicity of this major earthquake Sphere of influence. The far-field GPS continuous observation displacement time series and the coseismic displacement elastic dislocation model under the regional reference frame before and after the earthquake show that the horizontal displacement of the East Japan Great Earthquake is not only the result of the earthquake fault rupture but also a few months before the far-field earthquake or After several years of horizontal elastic rebound, we can further confirm the pre-seismic horizontal displacement precursory anomalies of these stations. Since these anomalous displacements also include the amount of coseismic displacement (in the opposite direction), the elastic dislocation model provides a theoretical model for the quantitative study of the anomalous crustal movement in the far-field before the major earthquake. The comprehensive study of coseismic displacements and dislocation models in dislocation reference frames and the displacement time series of regional reference frames can contribute to the understanding of the anomalous crustal movement in this major earthquake. This duration is elastic deformation anomalies of several months to several years, which can provide the basis for short-term and medium-term prediction of large earthquakes.