The subduction zones can be classified as two categories: accretion type and erosive type based on sediments supply. Due to lack of sediments subduction, the subduction crust can be “scratched” overlying crust and result in crustal blocks erosion. Those debris or crustal blocks are even under-thrusted between accretionary prism. In contrast to erosive type margin, physical properties of under-thrusting sediments which include porosity, consolidation status as well as pore pressure and effective stress can affect the activities of surrounding thrust faults. The resent study in the Cascadia margin offshore Canada shows that an over consolidation under-thrusting sediments is identified and suggests a strong coupling origin strongly based on earthquake studies. In the other hand, an under consolidation under-thrusting sediments regime located offshore Orogen State USA is associated with gas hydrate distribution on top of high fluid content under-thrusting sediments layer. This indicates that Orogen State region belongs to weak coupling area. Furthermore, a case study in the Alaska margin pointed out when subduction sediments are turbidity origin, it tends to be over pressure and reveal high potential to generate tsunamigenic earthquake. In first year project, we have analyzed several seismic profiles collected by TAIGER project. However, due to lack of seismic profiles southwestern offshore Taiwan and middle section of the northern Manila subduction system. In this project, we will collect new seismic data in those two area and combine analyze TAIGER data and new data to propose a physical property model of the under-thrusting sediments. We will also discuss the relationship between fluid within under-thrusting sediments and catastrophic earthquake.
Status | Finished |
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Effective start/end date | 1/08/20 → 31/07/21 |
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In 2015, UN member states agreed to 17 global Sustainable Development Goals (SDGs) to end poverty, protect the planet and ensure prosperity for all. This project contributes towards the following SDG(s):