Real-Time Seismic Intensity Measurements Prediction for Earthquake Early Warning: A Systematic Literature Review.

With the gradual development of and improvement in earthquake early warning systems (EEWS), more accurate real-time seismic intensity measurements (IMs) methods are needed to assess the impact range of earthquake intensities. Although traditional point source warning systems have made some progress in terms of predicting earthquake source parameters, they are still inadequate at assessing the accuracy of IMs predictions. In this paper, we aim to explore the current state of the field by reviewing real-time seismic IMs methods. First, we analyze different views on the ultimate earthquake magnitude and rupture initiation behavior. Then, we summarize the progress of IMs predictions as they relate to regional and field warnings. The applications of finite faults and simulated seismic wave fields in IMs predictions are analyzed. Finally, the methods used to evaluate IMs are discussed in terms of the accuracy of the IMs measured by different algorithms and the cost of alerts. The trend of IMs prediction methods in real time is diversified, and the integration of various types of warning algorithms and of various configurations of seismic station equipment in an integrated earthquake warning network is an important development trend for future EEWS construction.

Stochastic finite-fault method controlled by the fault rupture process.

We present an improved stochastic finite-fault method controlled by the fault rupture process (NNSIM) which can make the simulated strong ground motion at a broad frequency band similar to real ground motion of the Ms 7.0 Lushan earthquake by introducing the fault physical rupture process into the stochastic finite-fault method. Two obvious improvements are obtained: 1) the non-uniform time window functions produce various shape of the simulated time series instead of one single spindle shape; 2) the non-uniform stress drops and the non-uniform time window functions improve obviously simulated pseudo-spectral acceleration (PSA), especially, the low-frequency part. •We present an improved stochastic finite-fault method controlled by the fault rupture process (NNSIM) which can make the simulated strong ground motion at a broad frequency band similar to real ground motion by introducing the fault physical rupture process into the stochastic finite-fault method. Its validity was tested by the comparisons with records of Lushan earthquake.•The non-uniform time window functions produce various shape of the simulated time series instead of one single spindle shape.•The non-uniform stress drops and the non-uniform time window functions improve obviously simulated pseudo-spectral acceleration (PSA), especially, the low-frequency part.

Stochastic coupled simulation of strong motion and tsunami for the 2011 Tohoku, Japan earthquake.

This study conducts coupled simulation of strong motion and tsunami using stochastically generated earthquake source models. It is focused upon the 2011 Tohoku, Japan earthquake. The ground motion time-histories are simulated using the multiple-event stochastic finite-fault method, which takes into account multiple local rupture processes in strong motion generation areas. For tsunami simulation, multiple realizations of wave profiles are generated by evaluating nonlinear shallow water equations with run-up. Key objectives of this research are: (i) to investigate the sensitivity of strong motion and tsunami hazard parameters to asperities and strong motion generation areas, and (ii) to quantify the spatial variability and dependency of strong motion and tsunami predictions due to common earthquake sources. The investigations provide valuable insights in understanding the temporal and spatial impact of cascading earthquake hazards. Importantly, the study also develops an integrated strong motion and tsunami simulator, which is capable of capturing earthquake source uncertainty. Such an advanced numerical tool is necessary for assessing the performance of buildings and infrastructure that are subjected to cascading earthquake-tsunami hazards.