Analyzing the 1604 Quanzhou Tsunami Event by using Impact Intensity Analysis and Discovering the Potential Tsunami Threat along the West Coast of Taiwan

Abstract:

The event of 1604 Quanzhou earthquake induced a moderate tsunami with no significant damage report. However, the tsunami propagated over the Taiwan Strait and arrived in Hsinchu, Taiwan. Considering that half of the tsunami source region was in the inland area and the earthquake magnitude (Mw=7.5~8.0) was moderate, the tsunami signal was relatively large. This phenomenon also indicated that the tsunami was able to reach Taiwan with a small energy decaying rate. In this paper, we reconstructed the scenario which matched the historical records of the 1604 Quanzhou event, and further analyzed the sensitivity of location and magnitude to the wave height in Taiwan. We discovered that moving the source region offshore, the tsunami wave height increased on the north-western coast of Taiwan with dense population nowadays. In order to have thorough understanding of the potential threat tsunami can pose to the west coast of Taiwan, we performed impact intensity analysis (IIA). The IIA covered the region of Taiwan Strait and entire part of the South China Sea. The results showed that the potential tsunami threat of the northern part of the coast came mainly from the Quanzhou area, and the southern part would face the threat from the north segment of Manila Trench and the submarine landslide originating from the southwestern continental slope.