Reports say that the quake shook local structures and affected production at a Samsung Electronics Co. production facility but their were no casualties.
The epicenter of the quake, which hit off the coast northwest of Taean, at 4:48 a.m., was located 132 kilometers offshore, according to the Korea Meteorological Administration. It was the fourth-strongest since the agency began keeping records in 1978.
No tsunami occurred afterwards, nor is it expected to according to officials.
The brunt of the quake shook homes and other structures in Taean and Seosan, and some reported feeling its effects as far as Incheon and Seoul.
‘I was woken up because my bed was severely jolted. I was afraid,’ a resident in Incheon told Yonhap News Agency.
The quake was followed by a 2.3-magnitude aftershock about 9:25 a.m., according to the KMA.
‘More aftershocks can happen because the earlier earthquake was strong,’ said a KMA official. ‘You don’t have to worry about them because they cannot be as strong as the main one.’
According to Samsung, their production facilities were only briefly affected.
Extremely few facilities were briefly affected but were immediately restored, and no material damage was caused, Samsung Electronics said in an e-mailed statement. It’s impossible to confirm in detail which manufacturing lines were affected.
Initial concern was that it could have been caused by a nuclear test by North Korea. The USGS quake monitoring center has previously detected North Korean tests but, the location and depth do not suggest North Korean nuclear testing was the cause