A magnitude-4.9 earthquake struck offshore Kumamoto Prefecture, Japan, on Wednesday at approximately 1:05 p.m. local time [1, 2, 4].
The event is significant because the seismic activity reached across the sea, causing detectable shaking in South Korea.
The Japan Meteorological Agency said the epicenter was located 39 kilometers southwest of Kumamoto City [1, 3]. The hypocenter was recorded at a depth of 10 kilometers [1].
In South Korea, residents in Gwangju, South Jeolla Province, reported feeling weak vibrations from the quake [1, 2]. The tremors occurred during the early afternoon, according to YTN reporter Jeong Hye-yoon [1].
Officials said the magnitude-4.9 event was an aftershock [1, 2]. It follows a much larger magnitude-7.1 earthquake that struck the same region two weeks earlier [1, 2].
Seismic monitoring continues as the region stabilizes from the previous major event. No immediate reports of casualties or major infrastructure damage were included in the initial reports from the Japan Meteorological Agency [1].
“A magnitude-4.9 earthquake struck offshore Kumamoto Prefecture, Japan.”
The detection of a magnitude-4.9 quake in Gwangju highlights the seismic connectivity between the Japanese archipelago and the Korean peninsula. Because this event was an aftershock of a magnitude-7.1 quake, it indicates that the crust in the Kumamoto region remains unstable, increasing the risk of further tremors in the short term.
