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2004年在红海裂谷东侧的沙特阿拉伯西北部特布克城附近,发生了一系列震级≤5.1的浅源地震。由于该地区台站分布稀疏,这些地震不能被很好地定位,这也给确定这些地震与该地区绘制的断层之间的关联带来困难,从而无法提高地震灾害的评估。我们使用来自欧洲空间局(ESA)的环境卫星(Envisat)和资源遥感卫星2(ERS-2)的干涉合成孔径雷达(InSAR)数据来提高发生在2004年6月22日最大震级为MW5.1的地震序列的定位和震源参数。主震在干涉合成孔径雷达数据上显示为一个很小但是较明显的约2.7cm的位移信号,这显示了地震发生的位置,同时也显示地震目录上对地震的定位误差约为3~16km。基于贝叶斯估计,我们采用均匀半空间弹性介质中的有限断层模型来模拟干涉合成孔径雷达数据,发现主震发生在距特布克城东南约70km处,显示为一条正断层。南西倾向的断层,走向大致与红海裂谷平行,我们估计该地震的质心深度约为3.2km。断层模型不确定性在地表的投影显示主震可能发生在该区的一条西倾的正断层上,且该断层与红海平行。结果表明可以用干涉合成孔径雷达数据来提高中等强度地震的定位和识别现在的活动断层。
In 2004, a series of shallow earthquakes with magnitude ≤5.1 occurred near the city of Tebuquerque in the northwest of Saudi Arabia to the east of the Red Sea rift. Due to the sparse distribution of stations in the area, these earthquakes can not be well positioned, which also makes it difficult to ascertain the correlation between these earthquakes and the faults drawn in the area and therefore can not improve the assessment of earthquake disasters. We use Interferometric Synthetic Aperture Radar (InSAR) data from the European Space Agency (ESA) Envisat and the Resource Remote Sensing Satellite 2 (ERS-2) to improve the magnitude of the data that occurred on June 22, 2004, with a maximum magnitude of MW5.1 Seismic sequence location and source parameters. The main shock shows a small but significant displacement signal of about 2.7 cm on the SAR data, which shows the location of the earthquake and also shows that the positioning error on the earthquake catalog is about 3-16 km. Based on Bayesian estimation, we simulate the interferometric synthetic aperture radar data using a finite-fault model in a homogeneous half-space elastic medium and found that the main shock occurred at about 70 km southeast of the city of Tsibuk and showed a normal fault. The fault of the Southwest-prone fault runs roughly parallel to the Red Sea rift. We estimate that the earthquake has a centroid depth of about 3.2 km. The projection of the fault model uncertainty on the earth’s surface shows that the main shock may occur on a west-dipping normal fault in the area, and the fault is parallel to the Red Sea. Results show that interferometric synthetic aperture radar data can be used to improve the location of moderate-intensity earthquakes and to identify current active faults.