Thailand

Thailand's seismic hazard is primarily concentrated in its northern region, where the right-lateral Sagaing Fault system of Myanmar approaches the border and branches into Thailand's northern mountainous terrain as the Mae Klong and Three Pagodas fault systems. These faults accommodate the southeastward extrusion of the Indochina Block from the India-Asia collision zone. Central and southern Thailand, including Bangkok and the Gulf of Thailand coast, sit on the stable Sunda Shelf and experience low seismicity. The Chi Fault and Wang Chao Fault in northern Thailand have produced historical earthquakes, and the Mae Sariang and Mae Chan fault zones are active. The Andaman Sea to the west of southern Thailand overlies the Sunda subduction system, which despite being distant from the Thai landmass generated the 2004 tsunami that devastated Thailand's Andaman coast.

Thailand's modern seismic record includes the 2014 Chiang Rai earthquake (magnitude 6.3), the strongest instrumental earthquake recorded in Thailand, which killed one person, injured dozens, and caused significant damage to historic temples and buildings in the northern province. The 2011 Chiang Rai earthquake (magnitude 6.8, centred in Myanmar near the border) was strongly felt across northern Thailand. The 2007 earthquake near Mae Hong Son (magnitude 5.9) caused building damage in northern Thai communities. The December 2004 Sumatra-Andaman earthquake generated [[tsunami]] waves 2–10 metres tall that struck Thailand's Andaman coast, killing approximately 5,400 people including many foreign tourists at Khao Lak and Phuket. The total [[seismic-wave]] and tsunami hazard from the Sunda subduction zone thus exceeds the direct hazard from Thai onshore fault systems for much of the country.

The tectonic context of Thailand positions it within the Sundaland microcontinent — a relatively rigid crustal block that is being squeezed from the north by the India-Asia collision and from the south by the active subduction zones of the Sunda Arc. The major faults of northern Thailand are branches of the major left-lateral strike-slip systems of mainland Southeast Asia that accommodate the regional escape tectonics. Bangkok, built on very deep soft marine clay deposits — up to 80 metres thick in places — would be susceptible to significant [[seismic-wave]] amplification and [[liquefaction]] in the event of a major earthquake on the northern Thai fault systems, but such an event would require several hundred kilometres of propagation across the stable Thai plains. The Three Pagodas Fault and Mae Klong Fault represent the primary seismic risk for western Thailand and the region surrounding the historic city of Kanchanaburi.