Analyzing pressure variation at the ocean bottom induced by submarine earthquake and possible applications on tsunami detection

Although there have been no recent large-scale tsunamis, many research suggest the offshore area could generate megathrust earthquake and trigger a massive tsunami within the next 100 years. Thus, it’s important to enhanced tsunami forecasting system for submarine earthquake offshore Taiwan. To improve the locating capability for offshore earthquakes and tsunami monitoring, a cable-based ocean bottom seismographic observatory was constructed by the Central Weather Bureau (CWB). This system began operation at the end of 2011 and extends toward offshore southeastern Taiwan on 2020. The pressure gauge is used for track ocean bottom pressure change and plays a key role in many marine studies. One of their purposed is to rapid and accurate tsunami forecasting. In this project, we aim to compared pressure gauge with acceleration, velocity and displacement seismograms to better understand the relationship between pressure gauge records and non-tsunami components during submarine earthquake. We also compare the data with different sites to get more understanding about influence of water depth. We hope to clarify the characteristics of tsunami from the pressure variation and improve tsunami detection and install new station for Submarine cable seismic system.