A devastating earthquake with a magnitude of 7.7 on the Richter scale struck Myanmar, near Mandalay in March 2025. Merely twelve minutes later, a second major earthquake of magnitude 6.7 occurred about 31 km to the south of the initial epicentre. Both vents were shallow, originating at around 10 km (6 miles) depth, and triggered strong aftershocks in subsequent days. These earthquakes caused severe damage locally and were felt as far as 1,000 km away in Bangkok, Thailand. According to satellite data from the National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA), the earthquakes caused ground shifts exceeding 6 metres (approx. 20 feet) along the Sagaing Fault.
The Sagaing Fault is a major strike-slip fault that accommodates about 20 mm of lateral motion each year and extends over 700 km from the Andaman Sea in the south to northern Myanmar. It accommodates 50–55 per cent of the regional plate motion between India and Sunda plates. This fault had not experienced a large rupture in its central segment since the catastrophic Ava earthquake of 1839, making this event a long-anticipated release of accumulated tectonic stress.
The Sagaing Fault resembles the San Andreas Fault located in California in terms of movement, scale, and seismicity.
Ground Deformation and Satellite Observations
NASA’s Jet Propulsion Laboratory (JPL) together with the Advanced Rapid Imaging and Analysis (ARIA) team and the ESA analysed the ground movement during the twin earthquakes, utilising radar and optical satellite data using interferometric synthetic aperture radar (InSAR). Striking shifts were seen in the landscape exceeding 3 metres (i.e., 10 feet) apart from each other and the displacement was of over 6 metres (i.e., around 20 feet) at certain places along the fault. The mapped rupture extended approximately 460 km—nearly double the typical rupture length expected for an earthquake of this magnitude. Direct evidence of rapid surface slip was also captured through CCTV footage in settlements south of the epicentre.
Supershear Rupture Dynamics
Earthquakes typically start at a particular point on a fault and quickly extend along the fault by forming waves of energy (i.e., seismic waves), similar to the ripples in a water body. While typical ruptures propagate at a few kilometres per second, in this event, the rupture velocity was significantly higher.
Scientists identified the main cause of the twin earthquakes that struck Myanmar as a ‘supershear rupture’ that is a rare phenomenon. This phenomenon concentrates seismic energy ahead of the rupture, resulting in amplified shaking and thus, magnifying the destruction and human toll.
Detailed analysis confirmed that the rupture initially propagated southwards at supershear speeds of up to 5–6 km/s. It then reversed direction northwards at similar high speeds before again extending southwards, creating a unique ‘boomerang-like’ rupture pattern. This complex bilateral propagation concentrated seismic energy forward, resulting in intense and focused ground shaking far beyond the immediate fault zone—a phenomenon comparable to a sonic boon generated by supersonic aircraft.
Regional Tectonics
Southeast Asia is among the most tectonically active regions in the world, shaped by the ongoing oblique convergence between the Indian and Eurasian plates. This collision, which began around 40–50 million years ago, drives the northeastward movement of the Indian plate at about 5 cm per year, resulting in a complex network of faults and mountain-building processes.
This continuous convergence has produced some of the world’s most prominent geological features, including the Himalayas, Shillong plateau, Indo-Burman ranges, and the deep Andaman-Nicobar subduction zone.
This tectonic setting has produced some of history’s most powerful earthquakes, such as the 1792 Arakan earthquake (~M8.5), which caused a destructive tsunami in the Bay of Bengal, and the 2004 Indian Ocean earthquake (~M9.2), which caused widespread devastation across coastal regions. The frequent moderate-to-strong earthquakes further illustrate the region’s persistent seismic unrest.
Human and Structural Impact
Owing to the supershear earthquake in Myanmar, vigorous shaking caused extensive destruction of buildings near the epicentres. Approximately, 2.8 million people were directly affected. It is to note that its maximum population is living in timber-made houses that do not have any additional masonry elements to make them resilient at the time of calamities. These houses are particularly vulnerable to intense ground motions.
The disaster resulted in over 5,400 fatalities and more than 11,400 injuries. As per the ASEAN Coordinating Centre for Humanitarian Assistance on Disaster Management, over 300 hospitals and clinics; 2,500 schools; 55,000 houses; 95 bridges; and 400 roads were either highly damaged or completely destroyed. Economic losses were estimated to range from US$ 1.9 billion to US$ 11 billion.
Further, the United Nations Satellite Centre also assessed the damage and evaluated, over 1,000 buildings collapsed in the city named Mandalay, which was nearby the epicentre. Besides, 900 additional structures suffered severe damage.
The International Federation of Red Cross and Red Crescent Societies (IFRC) reported wide-spread displacement of around 2,00,000 people. They had no homes and were staying at public places. Over 468 aftershocks continued to disrupt the region in the following weeks.
Effects beyond Myanmar
The earthquake’s impact extended to Bangkok, about 670 km from the southern end of the rupture. Although the overall structural damage was limited, the collapse of a 33-storey under-construction building caused 63 deaths.
A striking phenomenon was observed due to the overflow of water from rooftop swimming pools. These oscillations, known as seismic seiches, are caused by long-period seismic waves that induce slow, amplified motions in high-rise structures and water bodies far from the source.
The soft sediment in Bangkok may have intensified the shaking of the ground during the earthquake. But experts have to still find out if these are actual causes of Bangkok being affected by the earthquake, which may take months or even years considering the outcome (a record of particular waveforms) of the seismometers installed in this region.
Unfortunately, there are very few seismic records within Myanmar, and no seismometers are present in the south of Myanmar (the Andaman sea region).
Dr Shengji Wei, the chief investigator at the Earth Observatory of Singapore (Nanyang Technological University), revealed that last year, almost two-thirds seismic monitors of the observatory were uninstalled in Myanmar due to the logistic issue concerning the COVID-19 pandemic and the coup.
Wei further remarked that strong motion data close to the ruptured fault couldn’t be collected. They also could not examine the seismic activity, such as several aftershocks, within the region.
Following the Myanmar earthquake, India launched Operation Brahma to deliver humanitarian assistance and disaster relief (HADR), reinforcing its position as the region’s ‘First Responder’.
Indian Navy ships Satpura, Savitri, the indigenous missile corvette Karmuk, and Landing Craft Utility (LCU) 52, (the second vessel of LCU MK-IV class) transported essential relief supplies to Yangon, Myanmar.
Conclusion
The 2025 Myanmar earthquakes stand out as a striking example of a rare and highly disruptive supershear rupture event. They highlighted the importance of advanced monitoring and early warning systems to reduced causalities and infrastructure loss in such high-risk regions.
Seismologists have called this event a ‘wake-up call’ for other major fault systems worldwide. The need to improve building codes, enforce urban planning regulations and strengthen regional and international seismic networks is now more urgent than ever.
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