The earthquake today, measured at between 7.4 and 7.7 on the Richter scale, was the strongest tremor felt in Thailand since 1930 when about 500 people were killed, said Phichit Sombatmak, director-general of the Mineral Resources Department.
He said that the tremor was first measured at 7.7 magnitude at 1.20pm, at a depth of about 10km. It was caused by the movement of the Sagaing fault in Mandalay, about 16km from Sagaing town and about 1,100km from Bangkok.
The quake was followed 12 minutes later by a 6.4 magnitude aftershock. The strong vibrations were felt in the northern, north-eastern, eastern and central regions of Thailand, including Bangkok, he said.
The provinces affected by the quake were Chiang Mai, Chiang Rai, Tak, Mae Hong Son, Lamphun, Lampang, Phitsanuloke, Khon Kaen, Nakhon Ratchasima, Udon Thani, Ubon Ratchathani, Chon Buri, Suphan Buri, Kanchanaburi, Nakhon Sawan, Ratchaburi, Lop Buri, Nakhon Nayok and Bangkok and its peripherals.
Phichit urged volunteers and the general public to monitor state media closely for news of any aftershocks.
Sagaing is a major fault in Myanmar. It is a mainly continental right-lateral transform fault, between the Indian and Sunda plates. It links the divergent boundary in the Andaman Sea with the zone of active continental collision along the Himalayan front.
It passes through the populated cities of Mandalay, Yamethin, Pyinmana, the capital of Naypyidaw, Toungoo and Pegu, before dropping off into the Gulf of Martaban, running for a total length of over 1,200km.
