Development of empirical relationship between P wave initial slopes and epicentral distance for early warning in South Korea

Abstract:

Earthquake early warning aims to rapidly provide the information of an earthquake to minimize earthquake damage. The location accuracy of an earthquake is crucial for the accurate estimation of the source property. While standard location procedure can take the advantages of using combined P-wave and S-wave information, early warning information should be given before arriving S-wave. Odaka et al. (2003) found that P-wave initial slopes decrease almost linearly with increasing epicentral distance and proposed a method for estimating epicentral distance from P-wave initial slope. The early warning system in the Japan Meteorological Agency uses this method for locating an earthquake when only one station triggers.

For developing the empirical relationship for earthquake early warning in South Korea, we investigate the relationship from 585 local earthquakes with magnitude larger than 2.0 and 147 regional earthquakes over magnitude 6.0 that occurred in and around the Korean Peninsula from 2005 to 2015.