According to the seismic data (mb≥5. 0) from 1977 to 1991 and the focal mechanisms of 68 earthquakes from 1961 to 1991, the characters of seismicity and stress field in Okinawa Trough and Ryukyu regions are discussed...According to the seismic data (mb≥5. 0) from 1977 to 1991 and the focal mechanisms of 68 earthquakes from 1961 to 1991, the characters of seismicity and stress field in Okinawa Trough and Ryukyu regions are discussed in this paper, and the paper suggests that: ① The Tokara Channel fault belt is a fault belt with seismicity, cutting through lithosphere. ② The different stress state in the both subducting slabs on the both sides of Tokara Channel fault belt are caused by the difference of subducting depth of the both slabs. ③ The seismicity and stress field in the Okinawa Trough and Ryukyu regions are related not only to the subduction of the Philippine Sea Plate but also to the self-expanding action of Okinawa Trough.展开更多
The Okinawa Trench in the East China Sea and the Manila Trench in the South China Sea are considered to be the regions with high risk of potential tsunamis induced by submarine earthquakes. Tsunami waves will impact t...The Okinawa Trench in the East China Sea and the Manila Trench in the South China Sea are considered to be the regions with high risk of potential tsunamis induced by submarine earthquakes. Tsunami waves will impact the southeast coast of China if tsunamis occur in these areas. In this paper, the horizontal two-dimensional Boussinesq model is used to simulate tsunami generation, propagation, and runnp in a domain with complex geometrical boundaries. The temporary varying bottom boundary condition is adopted to describe the initial tsunami waves motivated by the submarine faults. The Indian Ocean tsunami is simulated by the numerical model as a validation case. The time series of water elevation and runup on the beach are compared with the measured data from field survey. The agreements indicate that the Boussinesq model can be used to simulate tsunamis and predict the waveform and runup. Then, the hypothetical tsunamis in the Okinawa Trench and the Manila Trench are simulated by the numerical model. The arrival time and maximum wave height near coastal cities are predicted by the model. It turns out that the leading depression N-wave occurs when the tsunami propagates in the continental shelf from the Okinawa Trench. The scenarios of the tsunami in the Manila Trench demonstrate significant effects on the coastal area around the South China Sea.展开更多
文摘According to the seismic data (mb≥5. 0) from 1977 to 1991 and the focal mechanisms of 68 earthquakes from 1961 to 1991, the characters of seismicity and stress field in Okinawa Trough and Ryukyu regions are discussed in this paper, and the paper suggests that: ① The Tokara Channel fault belt is a fault belt with seismicity, cutting through lithosphere. ② The different stress state in the both subducting slabs on the both sides of Tokara Channel fault belt are caused by the difference of subducting depth of the both slabs. ③ The seismicity and stress field in the Okinawa Trough and Ryukyu regions are related not only to the subduction of the Philippine Sea Plate but also to the self-expanding action of Okinawa Trough.
基金financially supported by the National Natural Science Foundation of China(Grant No.11202130)the National Science Foundation of Shanghai Municipality(Grant No.11ZR1418200)the Doctoral Program Foundation of Higher Education(Grant No.20060248046)
文摘The Okinawa Trench in the East China Sea and the Manila Trench in the South China Sea are considered to be the regions with high risk of potential tsunamis induced by submarine earthquakes. Tsunami waves will impact the southeast coast of China if tsunamis occur in these areas. In this paper, the horizontal two-dimensional Boussinesq model is used to simulate tsunami generation, propagation, and runnp in a domain with complex geometrical boundaries. The temporary varying bottom boundary condition is adopted to describe the initial tsunami waves motivated by the submarine faults. The Indian Ocean tsunami is simulated by the numerical model as a validation case. The time series of water elevation and runup on the beach are compared with the measured data from field survey. The agreements indicate that the Boussinesq model can be used to simulate tsunamis and predict the waveform and runup. Then, the hypothetical tsunamis in the Okinawa Trench and the Manila Trench are simulated by the numerical model. The arrival time and maximum wave height near coastal cities are predicted by the model. It turns out that the leading depression N-wave occurs when the tsunami propagates in the continental shelf from the Okinawa Trench. The scenarios of the tsunami in the Manila Trench demonstrate significant effects on the coastal area around the South China Sea.
