On 28 March 2025, at 12:50:52 MMT (06:20:52 UTC), a moment magnitude () 7.7–7.9 earthquake struck the Sagaing Region of Myanmar, with an epicenter close to Mandalay, the country's second-largest city. The shaking caused by this strike-slip shock reached a maximum Modified Mercalli intensity of X (Extreme). It was the most powerful earthquake to strike Myanmar since 1912, and the second deadliest in Myanmar's modern history, surpassed only by upper estimates of the 1930 Bago earthquake. The earthquake caused extensive damage in Myanmar, particularly in areas near the rupture, and significant damage in neighboring Thailand. Hundreds of homes were also damaged in Yunnan, China, while more than 400 apartments were affected in Ho Chi Minh City, Vietnam.
The earthquake directly killed up to 5,352 people in Myanmar and 103 in Thailand, while one person died from shock in Vietnam. Up to 11,404 people were injured and hundreds more were reported missing. Most of the fatalities in Thailand occurred at a collapsed construction site in Bangkok, whose shallow geology makes it more vulnerable to seismic waves from far away. Authorities in both Myanmar and Thailand declared a state of emergency. As the earthquake struck during Friday prayer hours, collapsing mosques resulted in the deaths of hundreds of Muslims. In addition, more than 8,300 monasteries, nunneries and pagodas were destroyed. The ongoing civil war in Myanmar exacerbated the difficulty of disaster relief and info exposure.
Tectonic setting
Myanmar is wedged between four tectonic plates (the Indian, Eurasian, Sunda, and Burma plates) that interact in active geological processes. Along the west coast of the Coco Islands, off the Rakhine coast, and into Bangladesh, is a highly oblique convergent boundary known as the Sunda megathrust. This large fault marks the boundary between the Indian and Burma plates. The megathrust emerges from the seafloor in Bangladesh, where it runs parallel and east of the Chin Hills. This boundary continues to the north of Myanmar where it ends at the eastern Himalayas.
A transform fault runs through Myanmar and connects the Andaman spreading center to a collision zone in the north. Called the Sagaing Fault, it is a boundary between the Burma and Sunda plates as they slide past each other at per year. It is Myanmar's largest and most active source of earthquakes, running through or close to major cities including Yangon, Naypyidaw, and Mandalay. Large and damaging earthquakes occurred along the fault in May and December 1930 ( 7.3 & 7.5), 1931 ( 7.5), 1946 ( 7.3 & 7.7), 1956 ( 7.1), 1991 ( 6.8) and 2012 ( 6.9). The magnitudes of earthquakes on the Sagaing Fault vary across the fault zone from 7.0 to 8.0. The recurrence interval also varies depending on the location along the fault; its southern segments, which ruptured in 1930, have return periods of 100–150 years based on paleoseismological studies.
Destructive earthquakes have affected the area for centuries, but academic research has been limited. Most earthquakes in Myanmar, including large surface rupturing events, are thus not well understood. A large 8.5–8.8 earthquake in 1762 ruptured a section of the Sunda megathrust off the Rakhine coast. That earthquake may have been caused by the Indian plate subducting beneath the Burma plate along the megathrust. Remnants of the subducted Indian plate beneath central Myanmar also cause intraslab earthquakes; one example is the 1975 Bagan earthquake ( 7.0) which occurred at a depth of .
According to a study published in Journal of Geophysical Research: Solid Earth, the Sagaing Fault can be divided into two regions: the northern and southern sections. The Sagaing Fault between 16.5 and 23.5 degrees north latitude is defined as the southern section. It is further divided into five segments from south to north: the Bago, Pyu, Naypyidaw, Meiktila, and Sagaing segments. The Naypyidaw segment is characterised by two parallel faults running for with parts of them located beneath the capital city, Naypyidaw. The last recorded earthquake was in 1929 with a magnitude smaller than 7.0. The long Meiktila segment extends between Mandalay and Naypyidaw and is characterised as a linear feature. The nearly flat topography across this segment suggest the slip component is entirely horizontal. This segment has not experienced any major earthquakes, although it possibly ruptured during the 1839 Ava earthquake. The Sagaing segment is also another linear segment that runs parallel to the Irrawaddy River. The northern part of this segment ruptured during one of the mainshocks in the 1946 Sagaing earthquakes, while the 1956 Sagaing earthquake ruptured the southern strand.
This earthquake also affected Thailand, with damage primarily concentrated in the Bangkok region, about away from the epicenter. Bangkok's geology, characterised by a top layer of soft marine clay, renders its emerging high-rises vulnerable to distant, powerful earthquakes, as the ubiquitous clay layer contributes to local site effects amplifying long-period ground motion which in turn can match the resonant frequency of tall buildings. Occupants in Bangkok have often felt effects from earthquakes centered many hundreds or even thousands of kilometres away. Research headed by Pennung Warnitchai of the Asian Institute of Technology had previously identified the Sagaing Fault as a potential risk, if a magnitude-8.0 earthquake were to occur in the Andaman Sea, from the city, resulting in a future disaster. For preventing catastrophic effects in skyscrapers, elementary seismic considerations were only added to the building code in 2007, with older structures being particularly dangerous.
Earthquake
The earthquake occurred at 12:50:52 MMT, with its epicenter located in Sagaing Township near the Sagaing–Mandalay border region, north-northwest of Sagaing city and west of Mandalay, Myanmar's second largest city. It measured 7.7 on the moment magnitude scale according to the United States Geological Survey (USGS), while the Thai Meteorological Department put the local magnitude () at 8.2. Institut de Physique du Globe de Paris placed the earthquake's moment magnitude at 7.9. The China Earthquake Administration recorded the earthquake at 7.9 on the surface-wave magnitude. It is the largest earthquake with an epicenter in Myanmar since the 1912 Maymyo earthquake (which had an of 7.9). The focal mechanism solution indicated it occurred due to strike-slip faulting at a depth of . The type of faulting is consistent with rupture on the Sagaing Fault.
The earthquake was followed by more than 468 aftershocks by 12 April, according to the Thai Meteorological Department. These aftershocks were recorded in Myanmar and nearby regions including 13 events between magnitude 5.0 and 5.9. There were also 21 aftershocks recorded in Mae Hong Son with magnitudes of 1.4 to 3.9. These aftershocks in Myanmar were distributed along a zone of the Sagaing Fault, though they were sparse along the central portion of the rupture. The largest aftershock measured and occurred 12 minutes after the mainshock with a hypocenter beneath Mandalay International Airport. This aftershock also had a focal mechanism corresponding to strike-slip faulting.
Rupture process
According to a finite fault model released by the , the earthquake rupture extended about by from Singu in Mandalay to Kyauktaga in Bago. From the epicenter the rupture propagated more than to the north and terminated just north of Singu. More than of the rupture occurred to the south where it terminated near Kyauktaga. Slip of more than occurred non-uniformly across the entire rupture. Slip on the fault between Singu and Sagaing peaked at , while between Sagaing and Naypyidaw, generally exceeded . Parts of the fault exhibit as much as of slip from Wundwin to Naypyidaw with the latter location experiencing the highest slip. South of Naypyidaw, the slip generally does not exceed and tapers off by Kyauktaga. The entire rupture process took about 85 seconds with the greatest phase of seismic moment release occurring 20 seconds after initiation. The rupture is thought to have propagated at speeds in excess of the shear wave velocity, making this an example of a supershear earthquake.
Italy's National Institute of Geophysics and Volcanology published their finite fault model comprising three north–south trending segments. They proposed that each segment produced a magnitude 7.5 and ruptured for a total length of . The three segment ruptures corresponded in a cumulative moment magnitude of 7.8. According to their model, the earthquake produced a maximum slip of at a depth of along the central segment north of Naypyidaw. The earthquake produced one of the longest ruptures observed in the world, surpassing the lengths recorded by other large strike-slip events such as the 2002 Denali, 2009 Swan Islands, 2023 Turkey–Syria and 2013 Balochistan earthquakes.
Supershear rupture The rupture associated with the mainshock is one of the longest sustained supershear event and fastest ever recorded, and longest fault rupture ever known (). Based on empirical scaling relationships, the maximum expected rupture length for a strike-slip event of comparable magnitude is about only. Supershear rupture was inferred along the southern segment, although the extent along the fault where it occurred remains debated. Estimates range from based on back-projection imaging techniques to intermittent episodic supershear phases. The estimated rupture velocity also were as high as per second along the supershear segments.
Seismic gap A 2011 study by Nobuo Hurukawa and Phyo Maung Maung in Geophysical Research Letters identified two seismic gaps along the Sagaing Fault. One of these gaps is located in central Myanmar between 19.2 degrees north and 21.5 degrees north, corresponding to the Meiktila segment. The pair concluded that this gap could produce a magnitude 7.9 earthquake if it completely ruptures. The Meiktila and Sagaing segment (to the north) may have been the source of the 1839 Ava earthquake. It is believed to have ruptured of the fault on both segments. A study of the seismic intensity distribution suggest the estimated moment magnitude of the 1839 event was 7.9.
The 2025 earthquake ruptured the entire length of the Meiktila seismic gap, but also beyond to achieve its exceptionally long rupture length. The rupture propagated along the seismic gap, breaching its southern margin and overlapping the rupture areas of the 1929 event on the Naypyidaw segment and into the Pyu segment which produced the second earthquake of 1930 before terminating. In the north, the rupture extended about northwards from the hypocenter along the Sagaing segment. Here, it overlaps the 1956 and 1946 rupture zones before terminating at the southern extent of the 2012 earthquake. The 1929 rupture was reactivated in its entirety and the rupture continued about into the 1930 rupture zone in the south. The 1956 rupture zone was also reactivated along its full length together with about of the southern rupture extent of the 1946 earthquake.
Surface rupture The earthquake generated an exceptionally long surface rupture measuring as confirmed by satellite observations. It extended from Kyaukmyaung, Sagaing to Penwegon, Bago. Throughout most of the rupture, slip at the surface exceeded while around the epicenter area, reached . A study of satellite data at the Geospatial Information Authority of Japan revealed that up to of horizontal displacement occurred along the fault.