Explosion Traveled to Gangwon
By Jung Sung-ki
The alleged explosion that tore a South Korean warship into two in the West Sea (Yellow Sea) sent seismic waves through Cheolwon, in eastern Gangwon Province, about 200 kilometers from the site of the blast, a lawmaker said Saturday.
Citing data recorded by the Korean Institute of Geoscience and Mineral Resources, Rep. Noh Young-min of the main opposition Democratic Party said a seismological observatory on Baengnyeong Island, near the sea border with North Korea, detected seismic waves around 6.575Hz at 9:21:58 p.m., the time of the incident, on March 26.
The waves subsequently travelled through Gimpo, in Gyeonggi Province, about 170 kilometers from the epicenter and through Cheolwon, some 220 kilometers from it.
Observatories in Gimpo and Cheolwon detected waves around 5.418Hz at 9:30:41 p.m. and 2.532Hz at 9:32:53 p.m., respectively.
The institute said the explosion could have had the force of up to 260 kilograms of TNT.
Previously, the government and the military had assessed that the explosion could have been caused by a device equivalent to 180 kilograms of TNT.
Forty-four sailors are missing in action from the incident, while 58 were rescued and two seamen have been found dead.
Investigators are looking into the possibility of a torpedo attack or a sea mine explosion.