Generation and Validation of Broadband Synthetic P Waves in Semistochastic Models of Large Earthquakes
Generation and Validation of Broadband Synthetic P Waves in Semistochastic Models of Large Earthquakes
复制标题
DOI：
10.1785/0120200049
复制
发表时间：
2020-08
影响因子：
3
通讯作者：
D. Goldberg;D. Melgar
中科院分区：
文献类型：
--
作者：
D. Goldberg;D. Melgar
我们提出了一种生成随机情景破裂模型和半弹性宽带地震波形的方法，其中包括有效的P波，这是应用于预警系统测试的重要特征。可用于制定和完善预警程序的大震级地震观测资料很少；因此，模拟数据是一个有价值的补充。我们展示了使用Karhunen-Loève展开方法生成随机情景破裂模型的优势，因为它允许用户建立所需的空间质量，例如滑动反转，作为平均背景滑动模型。对于波形计算，我们在低频(1赫兹)采用确定性方法。我们的方法遵循Graves和Pitarka(2010)，并扩展到模型P波。我们提出了半反射宽带P波的首次验证，将我们的波形与2014年智利伊基克8.1兆瓦地震的观测结果在时间域和感兴趣的频率之间进行了比较。然后，我们使用一组为卡斯卡迪亚俯冲带的情景破裂产生的合成波形，更详细地考虑P波。我们证实，与时间相关的合成P波幅度增长与以前的分析是一致的，并演示了如何使用这些数据来模拟地震预警过程。
We present an approach for generating stochastic scenario rupture models and semistochastic broadband seismic waveforms that include validated P waves, an important feature for application to early warning systems testing. There are few observations of large magnitude earthquakes available for development and refinement of early warning procedures; thus, simulated data are a valuable supplement. We demonstrate the advantage of using the Karhunen–Loève expansion method for generating stochastic scenario rupture models, as it allows the user to build in desired spatial qualities, such as a slip inversion, as a mean background slip model. For waveform computation, we employ a deterministic approach at low frequencies (1 Hz). Our approach follows Graves and Pitarka (2010) and extends to model P waves. We present the first validation of semistochastic broadband P waves, comparing our waveforms against observations of the 2014 Mw 8.1 Iquique, Chile, earthquake in the time domain and across frequencies of interest. We then consider the P waves in greater detail, using a set of synthetic waveforms generated for scenario ruptures in the Cascadia subduction zone. We confirm that the time-dependent synthetic P-wave amplitude growth is consistent with previous analyses and demonstrate how the data could be used to simulate earthquake early warning procedures.