Seismic study points to explosion as cause of Cheonan ship sinking

SEOUL, Sept. 7 (Yonhap) -- An artificial seismic event that occurred at the time of a South Korean warship sinking last year indicates that an explosion was the cause of the sinking, a study showed Wednesday.
Hong Tae-kyung, a South Korean professor at Yonsei University, wrote in a recent paper that an earthquake of 1.5 magnitude occurred at the time of the Cheonan ship sinking on March 26 last year in the Yellow Sea. In the paper, published in the journal "Bulletin of the Seismological Society of America," Hong said the calculated location and time of the seismic event are close to the location and time of the Cheonan sinking, suggesting that the earthquake was associated with the sinking.



Hong also said his study of waves showed that the earthquake was an artificial one likely caused by an underwater explosion.
In May last year, a Seoul-led multinational probe concluded that North Korea had torpedoed the warship, killing 46 sailors aboard. North Korea has denied any responsibility.
Before the conclusion, experts had suggested metal fatigue of the ship or a collision with a reef as possible causes for the sinking.
According to Hong, metal fatigue doesn't generate seismic waves, and waves caused by a collision are similar to those of a natural earthquake.