Scientists clarify why Myanmar quake was so lethal

Rescue staff stroll previous development website particles after a constructing collapsed in Bangkok on March 28, 2025, following an earthquake. A strong earthquake rocked central Myanmar on March 28, buckling roads within the capital, Naypyidaw, damaging buildings and forcing folks to flee into the streets in neighbouring Thailand. —Photograph by Lillian Suwanrumpha | Agence France-Presse

BANGKOK, Thailand — Specialists say that the devastating earthquake in Myanmar on Friday was doubtless the strongest to hit the nation in a long time, with catastrophe modeling suggesting 1000’s may very well be lifeless.

Computerized assessments from the USA Geological Survey (USGS) mentioned the shallow 7.7-magnitude quake northwest of the central Myanmar metropolis of Sagaing triggered a crimson alert for shaking-related fatalities and financial losses.

“Excessive casualties and in depth harm are possible, and the catastrophe is probably going widespread,” it mentioned, finding the epicenter close to the central Myanmar metropolis of Mandalay, house to greater than one million folks.

Myanmar’s ruling junta mentioned on Saturday morning that the quantity killed had handed 1,000, with greater than 2,000 injured.˝

Nonetheless, the USGS evaluation mentioned there was a 35 % probability that fatalities may very well be within the vary of 10,000 to 100,000 folks.

READ: Myanmar’s quake demise toll rises to over 1,000; extra our bodies are recovered

The USGS supplied an analogous chance that the monetary harm might whole tens of 1000’s of thousands and thousands of {dollars}, warning that it’d exceed the GDP of Myanmar.

Weak infrastructure will complicate aid efforts within the remoted, military-ruled state, the place rescue providers and the healthcare system have already been ravaged by 4 years of civil battle sparked by a navy coup in 2021.

Harmful fault

Invoice McGuire, emeritus professor of geophysical and local weather hazards at College School London (UCL), mentioned it was “most likely the most important earthquake on the Myanmar mainland in three-quarters of a century”.

A 6.7-magnitude aftershock struck minutes after the primary, and McGuire warned that “extra might be anticipated.”

Rebecca Bell, a tectonics professional at Imperial School London (ICL), urged it was a side-to-side “strike-slip” of the Sagaing Fault.

That is the place the Indian tectonic plate, to the west, meets the Sunda plate that kinds a lot of Southeast Asia — a fault comparable in scale and motion to the San Andreas Fault in California.

“The Sagaing fault could be very lengthy, 1,200 kilometres (745 miles), and really straight,” Bell mentioned. “The straight nature means earthquakes can rupture over massive areas — and the bigger the realm of the fault that slips, the bigger the earthquake.”

Earthquakes in such circumstances might be “notably harmful,” Bell added, explaining that for the reason that quake takes place at a shallow depth, its seismic vitality has dissipated little by the point it reaches populated areas above.

That causes “loads of shaking on the floor,” Bell mentioned.

Constructing increase

Myanmar has been hit by highly effective quakes previously.

There have been greater than 14 earthquakes with a magnitude of 6 or above previously century, together with a magnitude 6.8 earthquake close to Mandalay in 1956, mentioned Brian Baptie, a seismologist with the British Geological Survey.

Ian Watkinson, from the division of earth sciences at Royal Holloway College of London, mentioned what had modified in latest a long time was the “increase in high-rise buildings constructed from strengthened concrete.”

Myanmar has been riven by years of battle and there’s a low stage of constructing design enforcement.

“Critically, throughout all earlier magnitude 7 or bigger earthquakes alongside the Sagaing Fault, Myanmar was comparatively undeveloped, with principally low-rise timber-framed buildings and brick-built non secular monuments,” Watkinson mentioned.

“In the present day’s earthquake is the primary check of recent Myanmar’s infrastructure in opposition to a big, shallow-focus earthquake near its main cities.”

Baptie mentioned that not less than 2.8 million folks in Myanmar have been in hard-hit areas the place most lived in buildings “constructed from timber and unreinforced brick masonry” which can be weak to earthquake shaking.

“The same old mantra is that ‘earthquakes don’t kill folks; collapsing infrastructure does’,” mentioned Ilan Kelman, an professional in catastrophe discount at UCL.

“Governments are chargeable for planning laws and constructing codes. This catastrophe exposes what the governments of Burma/Myanmar did not do lengthy earlier than the earthquake, which might have saved lives through the shaking.”

Skyscraper checks

Sturdy tremors additionally rocked neighboring Thailand, the place a 30-story skyscraper beneath development was decreased to a pile of dusty concrete, trapping staff within the particles.

Christian Malaga-Chuquitaype, from ICL’s civil and environmental engineering division, mentioned the character of the bottom in Bangkok contributed to the impression on the town, regardless of being some 1,000 kilometres (620 miles) from the epicentre in Myanmar.

“Despite the fact that Bangkok is way from energetic faults, its tender soil amplifies the shaking,” he mentioned. “This impacts particularly tall buildings throughout distant earthquakes.”

Malaga-Chuquitaype mentioned the development strategies in Bangkok favoring “flat slabs” — the place flooring are held solely by columns with out utilizing strengthening beams, like a desk supported solely by legs —have been a “problematic design.”

He mentioned that an preliminary video evaluation of the collapsed tower block in Bangkok urged such a development method had been used.

“It performs poorly throughout earthquakes, usually failing in a brittle and sudden (nearly explosive) method,” he mentioned.

Roberto Gentile, a disaster threat modelling professional from UCL, mentioned the “dramatic collapse” of the Bangkok tower block meant that “different tall buildings within the metropolis might require an intensive evaluation.”

Bangkok metropolis authorities mentioned they might deploy greater than 100 engineers to examine buildings for security after receiving greater than 2,000 studies of harm.