【摘要】 对汶川地震震中附近450 km范围内倾斜仪、应变仪记录到的同震变化做了筛选统计,并根据弹性半无限空间矩形位错模型,分别采用远场地震波资料、近场大地测量资料反演的同震滑移分布模型,正演计算震中附近台站的同震倾斜、应变变化。通过对实际观测与模拟计算结果的比较,初步表明:实际观测的同震倾斜变化方向与模拟计算结果存在75%的一致性,实际观测的同震倾斜变化比模拟值大约1～2个量级;实际观测的同震应变方向与模拟计算结果仅有33.3%的一致性,实际观测的同震应变变化与模拟计算值相当或仅大1个数量级。更多还原

【Abstract】 Coseismic tilt and strain offsets for Wenchuan Ms8.0 earthquake had been recorded by almost all of the continuous tilt and strain instruments in China.These offsets can be interpreted as qui-static tectonic changes after the earthquake.We calculate coseismic tit and strain offsets at the stations around about 450 km of the epicenter and coseismic tilt and strain offsets are simulated with half-space elastic dislocation model,particalarly using finite slip models inversed from far-field broadband seismic waveforms and from near-field geodetic data(GPS&InSAR).Consequently,comparisons between the observed and modeled offsets for tilt-and strain-meters are analyzed.Our preliminary study demonstrates that the directions of observed ～75% tilt offset and ～33.3% strain offset are consistent with that modeled,respectively,and the magnitude of the observed tilt offsets are 1-2 orders larger than that of modeled,whereas the observed strain offsets are coherent with the modeled or 1 orders of magnitude larger than that of modeled.更多还原