한국지구물리탐사학회:학술대회논문집
- 2007.06a
- /
- Pages.64-68
- /
- 2007
Estimation of epicenter using an empirical relationship between epicentral distance and traveltime of the first arrival
초동 전파시간과 진앙거리의 경험적인 관계를 이용한 진앙 추정
- Sheen, Dong-Hoon (Global Environment System Research Lab., METRI) ;
- Baag, Chang-Eob (School of Earth and Environmental Sciences, SNU) ;
- Hwang, Eui-Hong (Director for Earthquake Policy, KMA) ;
- Jeon, Young-Soo (Global Environment System Research Lab., METRI)
- Published : 2007.06.07
Abstract
The classic graphical method to determine the epicenter uses differences between the arrival times of P and S waves at each station. In this research, a robust approach is proposed, which provides a fast and intuitive estimation of earthquake epicenters. This method uses an empirical relationship between epicentral distance and traveltime of the first arrival P phase of local or regional earthquake. The relationship enables us to estimate epicentral distances and draw epicentral circles from each station with P-traveltimes counted from a probable origin time. As the assigned time is getting close to the origin time of the earthquake, epicentral circles begin to intersect each other at a possible location of the epicenter. Then the possibility of the epicenter can be expressed by a function of the time and the space. We choose the location which gives the minimum standard deviation of the origin time as an estimated epicenter. In this research, 918 P arrival times from 84 events occurring from 2005 to 2006 listed in the KMA earthquake catalog are used to determine the empirical P-traveltime function of epicentral distances.