Investigation of Local Tsunami Effect on Coastal Areas: A Case Study of Putian City, Fujian Province, China

Abstract

In this paper, we explored the local tsunami hazards induced by an active local seismic Quanzhou fault, along the coastlines of the City of Putian, Fujian Province, in the southeast of China. The simulation results indicated that the tsunami wave will hit the nearest coast of Putian 0.5 h after the earthquake occurs. The most serious tsunami inundation depth in Putian was less than 3.0 m. This study also conducted a sensitivity test of the tsunami amplitude and inundation in response to different seismic source parameters, particularly the rake and strike angles of the Quanzhou fault. Based on the post-earthquake survey and the most updated geophysical data, the uniform dislocation distribution is applied in the range of scientific geometrical characteristic parameters for numerical modeling. A 20° change in the rake angle increases the inundation area from 50.0 km2 to more than 100.0 km2, and increases the tsunami amplitude from 0.2 m to 1.0 m. In this study, the tsunami hazard of Putian is more sensitive to the rake than to the strike angle for a local fault. Tsunamis generated by seismic fault could also result in serious coastal flooding along the coastlines locally, and the time for emergency response is limited. The research results could provide technical support for refining local tsunami hazard assessment and contingency plans, to save decision-making time and avoid waste of social resources.

Scenario-Based Hazard Assessment of Local Tsunami for Coastal Areas: A Case Study of Xiamen City, Fujian Province, China

“…The change in fault rake angle will affect the vertical seabed displacement, thus determining the size of the tsunami. In the study conducted by Fan et al [14], the sensitivity of maximum tsunami amplitude and coastal inundation to rake and strike angle was investigated. They deduced that the tsunami hazard of affected area is more influenced by the rake angle than by the strike angle for a local fault based on analysis of the distribution of maximum tsunami amplitude in the near shore.…”

“…Throughout history, the waters near Xiamen have experienced several tsunamis. In 1604, a tsunami was induced by a Mw7.5 earthquake that occurred along the coast of Quanzhou [14,28]. In 1918, a descending tsunami induced by the Mw7.5 earthquake off the coast of Nan'ao Island affected several cities along the coast of southern China [29,30].…”

“…They conducted a tsunami hazard assessment at Oeiras municipality (Portugal) based on the tsunami arrival time and water level height. Fan et al [14] used the COMCOT model to simulate a worst-case local tsunami scenario caused by the maximum credible earthquake (Mw8.0) occurring at the Quanzhou fault along China's southeast coast and conducted a tsunami hazard analysis of the coastal area of Putian City based on the tsunami inundation depth. The results of these studies are essential for the prevention and mitigation of tsunami disasters in the affected regions.…”

A Review of Historical Volcanic Tsunamis: A New Scheme for a Volcanic Tsunami Monitoring System

“…Tsunami monitoring and early warning for earthquakes are relatively mature [37][38][39], and the current operational ranges for tsunami warning agencies are mainly for seismogenic tsunamis, and most have fixed standard operating procedures. The widely adopted approach is to determine the event information of the submarine source location, magnitude, depth, etc., when an earthquake happens.…”

Tsunami risk research on coastal areas in Fujian Province, China

“…The nonlinear shallow water equations are adopted for grid 3. Considering the influence of tides on tsunami, a 19yr data of monthly mean high tide level of Xiuyu Station is used to promote the accuracy of the simulation, [14]. The situation of inundation is not considered and only the grids in water are calculated in simulation.…”