Numerical and Probabilistic Study on the Optimal Region for Tsunami Detection Instrument Deployment in the Eastern Sea of Korea

Abstract

A tsunami is a significant coastal hazard that causes destructive damage to coastal cities in the world. Besides, tsunamis, generated on the west coast of Japan, damaged coastal cities on the east coast of Korea in 1983 and 1993. In recent years, there has been increasing interest in the potential tsunami zone near the west coast of Japan. Therefore, it is important to have tsunami observation instruments in proper locations for tsunami detection and warning aspect. This study proposes the optimal region for offshore tsunami observation instrument deployment under the limited condition that the tsunami source in out of the territorial sea by investigating areas with the highest tsunami detection probability along with maximum evacuation time and bottom slope. Using the Cornell Multi-grid Coupled Tsunami (COMCOT) numerical model and a probabilistic approach, this study suggests the optimal region for offshore tsunami detection instrument deployment to be the northeast area of Ulleung-do Island in the eastern sea of Korea.

Optimal Tide Gauge Location for Tsunami Validation in The Lembeh Island, North Sulawesi

“…In this study, the placement location candidate was used as the alternative option, while the three optimal location criteria from Lee et al (2020) were as the criteria. The three criteria have the same effect in determining the optimal tide gauge location, so each of them has a weight value of 1.0.…”

“…Due to limited tsunami events in this area and limited tsunami observation data on the east coast of Lembeh Island, the arrival time and time-series tsunami height data at each candidate location are obtained from tsunami propagation modeling. Lee et al (2020) and Meza et al (2020) also use numerical tsunami modeling to determine the best location of tsunami detection instruments in Korea and Chile, respectively. Based on USGS (2020), major earthquakes with a magnitude above 7.0 concentrate in the middle of the Molucca Sea.…”

“…Therefore, the optimal location of the tide gauge was analyzed on the east coast of Lembeh Island, so that the people in the coastal area of Bitung have enough time for evacuating before a tsunami happens. Lee et al (2020) explained that the high tsunami detection potential, maximum evacuation time, and the proper site for tsunami observation instrument installation are the criteria for determining the best location for the tsunami observation instrument. The third criteria can become the limitation in finding the optimal location for placing the tide gauge on the east coast of Lembeh Island, because tide gauges can only be installed on beaches with a dock.…”

Feasibility Analysis of GNSS-Reflectometry for Monitoring Coastal Hazards

“…Each node contains seismometers, bottom pressure recorders, and hydrophones, etc. [3]. These networks are installed in the open ocean for direct measurements of tsunami waves.…”