
The National Disaster Warning Centre reported that the quake at Koh Yao at 1.02pm was about two kilometres below the surface. There were no reports of a tsunami.
Phuketwan online quoted a reader as saying the tremor was felt at Phuket's central Heroine's Monument for about six seconds.
Another reader based in southern Phuket at Chalong said: “I felt a light shaking that lasted maybe 1015 seconds . . . not sure at first if it was an earthquake or maybe a passing large vehicle, but quite noticeable.”'
“'We were on the beach at Nai Yang [near Phuket airport] and felt it there,” said one caller to Phuketwan. “But there was no panic.”
Meanwhile Passakorn Pananon, a lecture of the Earth Sciences Department, Kasetsart University, said the quake took place at the end of the 150-km-long Klong Marui fault line that cuts across Surat Thani’s Ban Ta Khun and Panom districts and Phang Nga’s Tab Phut and Muang districts.
Passakorn said this fault was responsible for many quakes though they were usually so small they did not attract attention. About two years ago, an earthquake shook Phuket island, which is near this spot.
This level of tremor would not generate a tsunami, which usually only occur when the quake registers more than 6 magnitude and is vertical in nature.
However he said the situation should be monitored for a while as the quake may be followed by aftershocks. “The first earthquake is not necessarily to the biggest one, so the next tremor might be stronger,” he said.