Scientists clarify why Myanmar quake was so lethal

Rescue staff stroll previous building 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. —Picture by Lillian Suwanrumpha | Agence France-Presse

BANGKOK, Thailand — Consultants 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 america Geological Survey (USGS) mentioned the shallow 7.7-magnitude quake northwest of the central Myanmar metropolis of Sagaing triggered a pink alert for shaking-related fatalities and financial losses.

“Excessive casualties and in depth injury are possible, and the catastrophe is probably going widespread,” it mentioned, finding the epicenter close to the central Myanmar metropolis of Mandalay, dwelling to greater than 1,000,000 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 % likelihood that fatalities may very well be within the vary of 10,000 to 100,000 folks.

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

The USGS supplied an analogous probability that the monetary injury may complete tens of 1000’s of thousands and thousands of {dollars}, warning that it would exceed the GDP of Myanmar.

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

Harmful fault

Invoice McGuire, emeritus professor of geophysical and local weather hazards at College Faculty London (UCL), mentioned it was “in all probability the largest 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 could be anticipated.”

Rebecca Bell, a tectonics professional at Imperial Faculty London (ICL), advised 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 varieties a lot of Southeast Asia — a fault comparable in scale and motion to the San Andreas Fault in California.

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

Earthquakes in such instances could be “notably harmful,” Bell added, explaining that because the quake takes place at a shallow depth, its seismic power has dissipated little by the point it reaches populated areas above.

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

Constructing increase

Myanmar has been hit by highly effective quakes up to now.

There have been greater than 14 earthquakes with a magnitude of 6 or above up to now 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 current a long time was the “increase in high-rise buildings constructed from bolstered concrete.”

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

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

“Right this moment’s earthquake is the primary take a look at 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 had been in hard-hit areas the place most lived in buildings “constructed from timber and unreinforced brick masonry” which can be susceptible to earthquake shaking.

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

“Governments are answerable for planning rules 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 in the course of the shaking.”

Skyscraper checks

Sturdy tremors additionally rocked neighboring Thailand, the place a 30-story skyscraper underneath building 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 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 comfortable 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 —had been a “problematic design.”

He mentioned that an preliminary video evaluation of the collapsed tower block in Bangkok advised one of these building method had been used.

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

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

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