Kinematic earthquake rupture inversion in the frequency domain
Kinematic earthquake rupture inversion in the frequency domain
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DOI：
10.1093/gji/ggu319
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发表时间：
2014-11
影响因子：
2.8
通讯作者：
W. Fan;P. Shearer;P. Gerstoft
中科院分区：
文献类型：
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作者：
W. Fan;P. Shearer;P. Gerstoft
我们开发了一种基于频率的地震滑动反演方法，该方法不需要破裂速度或滑动率函数的先验信息。由于反演是线性的，并且在每个频率上分别进行，因此计算效率高，适合成像破裂的最精细的可分辨空间细节。本文以当地记录的6.6级地壳走滑地震震源反演验证演练1 （SIV1）为基础，对合成地震图进行了验证。通过在断层模型边缘施加阻尼、平滑和强制零滑移的组合，获得了一种鲁棒的反演方法。该方法实现了合理的数据拟合，总体上符合SIV1模型，包括每个子断层的滑动率函数，从中可以提取其总滑动、滑动时程和破裂速度。我们通过探索噪声、随机时序误差和故障几何误差的影响来证明该方法的鲁棒性。对反演影响最大的是假定断层几何形状的误差。
SUMMARY We develop a frequency-based approach to earthquake slip inversion that requires no prior information on the rupture velocity or slip-rate functions. Because the inversion is linear and is performed separately at each frequency, it is computationally efficient and suited to imaging the finest resolvable spatial details of rupture. We demonstrate the approach on synthetic seismograms based on the Source Inversion Validation Exercise 1 (SIV1) of a crustal M w 6.6 strike-slip earthquake recorded locally. A robust inversion approach is obtained by applying a combination of damping, smoothing and forcing zero slip at the edge of the fault model. This approach achieves reasonable data fits, overall agreement to the SIV1 model, including slip-rate functions of each subfault, from which its total slip, slip time history and rupture velocity can be extracted. We demonstrate the method’s robustness by exploring the effects of noise, random timing errors, and fault geometry errors. The worst effects on the inversion are seen from errors in the assumed fault geometry.