High-resolution source imaging based on time-reversal wave propagation simulations using assimilated dense seismic records
High-resolution source imaging based on time-reversal wave propagation simulations using assimilated dense seismic records
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DOI：
10.1093/gji/ggaa586
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发表时间：
2021-01-14
影响因子：
2.8
通讯作者：
Maeda, Takuto
中科院分区：
文献类型：
--
作者：
Furumura, Takashi;Maeda, Takuto
本文描述了一种高分辨率时间反演源成像模拟的有效方法。密集的地震台网记录通过三维地下结构模型从台站反向传播到震源，以估计地震发生时的初始震源波场。通过将高密度观测数据同化到时间反演波传播中，可以确定比传统震源成像更清晰的震源图像，即使对于深源和远源地震也是如此。使用2007年日本新泻近海M-w 6.6地震和2007年日本茨木近海M-w 6.8地震期间全国强震仪网络的记录，证明了通过采用三维非均匀结构模型的时间反演波传播模拟进行的基于数据同化的震源成像的有效性。这样的数据同化为基础的模拟也是有效的早期预报强地面运动引起的大地震通过快速时间推进模拟的基础上，目前的同化波场。我们将讨论一个灾害预防系统的可行性，由于大地震的强震灾害的早期预测，基于反复估计源参数和预测强震在未来的时间，根据目前同化波场。
This paper describes an efficient approach to high-resolution time-reversal source imaging simulation. Dense seismograph network records are backpropagated from stations to the hypocentre through a 3-D subsurface structure model to estimate the initial source wavefield at the earthquake initiation time. By assimilating high-density observational data into the time-reversal wave propagation, a clearer source image can be determined, even for deep and distant earthquakes, than is achievable with conventional source imaging. The effectiveness of data-assimilation-based source imaging by a time-reversal wave propagation simulation with a 3-D heterogeneous structural model was demonstrated using recordings from a nationwide strong-motion seismograph network during the 2007 Off Niigata, Japan, M-w 6.6 earthquake, and the 2007 Off Ibaraki, Japan, M-w 6.8 earthquake. Such data-assimilated-based simulations are also effective for early forecasting of strong ground motions caused by large earthquakes through fast time-advancing simulations based on the current assimilated wavefield. We will discuss the feasibility of a disaster prevention system for the early forecasting of strong motion disasters due to large earthquakes, based on repeatedly estimating source parameters and forecasting strong motions in future time based on the current assimilated wavefields.