Some of My Works

Study the Causes of Double P Phases observed around Northeastern Taiwan

Previous studies observed dual P phases from the signals of several deep events beneath Northeastern Taiwan. They identified that the anomalous observations are caused by the scattering from magma diapirs on the basis of a 1D layered model and ray-tracing method. However, waveform modeling based on the model with heterogeneities is necessary for explaining this complicated path effect. Here, we construct the velocity models on the basis of previous tomographic studies. Next, we simulate the waveforms using these self-created models, in order to find the model with the smallest misfit. According to our result, the high-velocity zone below Northeastern Taiwan and the interface between the mantle wedge and the high-velocity Eurasian lithosphere might be the main causes for producing the double P phases. 


Validating the Joint inverted tomographic model using numerical waveform modeling

In our group, we have developed a high-resolution seismic imaging around Yilan, Taiwan using the data of body wave, surface wave, and ambient noise. Here, we utilize the numerical waveform modeling to assess the reliability of this velocity model. By placing a single-force source slightly beneath a specific station, we can extract the Green's function between every station pair. Therefore, the similarity between observational and synthetic Green's function demonstrates the robustness of incorporating ambient noise data into the joint inversion.

Numerical Validation on the RMS Amplitude Ratio Method for Strain Data

The technique of Distributed Acoustic Sensing (DAS) has become a popular way to record seismic signals. The widely deployed fiber cables can function as an extremely high-density seismic array. However, the data from DAS are recorded in strain format rather than velocity. Robustly converting strain data to velocity is difficult and complicated. Therefore, our group has developed a new method called 'RMS amplitude ratio method' to explore the velocity structures using the strain data. If you are interested in this method, please check this out. Here, we validate the robustness of this method through 2D numerical modeling. As the result, the simulations can fit the data well, revealing the feasibility of this method.