Seismic activity characteristics in the East Sea area

Abstract

In this paper, seismic activity characteristics in the East Sea area was analyzedby authors on thebase of the unified earthquake catalog (1900-2017), including 131505 events with magnitude 3≤Mw≤8.4. The seismic intensity in the East Sea during the period 1900 - 2017 is characterized by the earthquake representative level Mw= 4.7. The strong earthquake activity in the East Sea area clearly shows the regularity in each stage. In the period from 1900 to 2017, the East Sea area has four periods of strong earthquake activity, eachstageis nearly 30 years with particular characteristics. The distribution of the maximum earthquake quantities by years has a cyclicity in all four periods. In each stage there are 1-2 strong earthquakes with Mmax ≥ 8.0. The strong earthquakes with Mmax ≥ 7.5 have occurred by a repeatable rule of 3-5 years in all four stages. This allows the prediction of the maximum earthquake repeat cycle of Mmax ≥ 7.5 in the study area is 3-5 years. In other hand, the maximum magnitude values for the East Sea region has assessed by GEV method with several different predict period (20, 40, 60, 80, 100 years), with predicted probability 80%. We concluded that it is possible that earthquake have Mmax = 8. 7 will occur in next 100 years.