Scientists clarify why Myanmar quake was so lethal

Rescue employees stroll previous development web site particles after a constructing collapsed in Bangkok on March 28, 2025, following an earthquake. A robust earthquake rocked central Myanmar on March 28, buckling roads within the capital, Naypyidaw, damaging buildings and forcing individuals 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 probably the strongest to hit the nation in many years, with catastrophe modeling suggesting 1000’s might be useless.

Automated assessments from america Geological Survey (USGS) stated 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 intensive harm are possible, and the catastrophe is probably going widespread,” it stated, finding the epicenter close to the central Myanmar metropolis of Mandalay, house to greater than one million individuals.

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

Nonetheless, the USGS evaluation stated there was a 35 p.c probability that fatalities might be within the vary of 10,000 to 100,000 individuals.

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

The USGS provided an identical chance that the monetary harm may complete tens of 1000’s of hundreds of 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 conflict sparked by a navy coup in 2021.

Harmful fault

Invoice McGuire, emeritus professor of geophysical and local weather hazards at College Faculty London (UCL), stated 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 will be anticipated.”

Rebecca Bell, a tectonics knowledgeable 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 could be very lengthy, 1,200 kilometres (745 miles), and really straight,” Bell stated. “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 instances will be “notably harmful,” Bell added, explaining that for the reason that quake takes place at a shallow depth, its seismic power has dissipated little by the point it reaches populated areas above.

That causes “a number of shaking on the floor,” Bell stated.

Constructing increase

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

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

Ian Watkinson, from the division of earth sciences at Royal Holloway College of London, stated what had modified in current many years 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 largely low-rise timber-framed buildings and brick-built non secular monuments,” Watkinson stated.

“In the present day’s earthquake is the primary take a look at of contemporary Myanmar’s infrastructure towards a big, shallow-focus earthquake near its main cities.”

Baptie stated that a minimum of 2.8 million individuals 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 individuals; collapsing infrastructure does’,” stated Ilan Kelman, an knowledgeable in catastrophe discount at UCL.

“Governments are liable 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 development was decreased to a pile of dusty concrete, trapping employees within the particles.

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

“Though Bangkok is much from energetic faults, its smooth soil amplifies the shaking,” he stated. “This impacts particularly tall buildings throughout distant earthquakes.”

Malaga-Chuquitaype stated 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 stated that an preliminary video evaluation of the collapsed tower block in Bangkok advised one of these development method had been used.

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

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

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