The Earthquake That Raced at Supersonic Speed – And Tore a 400km Scar Through Myanmar

A powerful 7.7 magnitude earthquake ripped across central Myanmar, producing one of the world’s largest fault ruptures and causing devastation across Myanmar and nearby regions.

Seismologists presented groundbreaking insights on the rupture’s supershear speed, triggered aftershocks in neighboring countries, and the intense shaking that crippled infrastructure. New tools like satellite mapping and submarine cable sensors are changing how fast and effectively we respond to such disasters.

Massive Earthquake Devastates Myanmar

A powerful magnitude 7.7 earthquake struck near Mandalay, Myanmar (formerly Burma) on March 28, causing widespread and severe damage across the country and in neighboring areas, including Thailand. More than 5,000 casualties have been confirmed. At the Seismological Society of America’s Annual Meeting, researchers from around the world shared early findings on the quake’s fault behavior, ground shaking, and impacts on infrastructure.

Tectonic Tensions Along the Sagaing Fault

Myanmar lies in a tectonically active zone where the India and Eurasia plates collide. The March earthquake ruptured over 400 kilometers of the Sagaing Fault – a major strike-slip fault that runs through central Myanmar – according to U.S. Geological Survey seismologist Susan Hough.

This rupture is among the largest surface breaks ever recorded globally, said USGS researcher Nadine Reitman. While the Sagaing Fault has produced several magnitude 6 and larger earthquakes in the past century, this particular section had not experienced a magnitude 7 event since 1839.

Widespread Seismic Activity in the Aftermath

The rupture went “supershear” – rupturing faster than the speed of sound – after an initial slow start, as would be expected for a large strike-slip earthquake, said Zhigang Peng of Georgia Institute of Technology. Peng noted that earthquake catalogs in Thailand and Yunnan and Guangdon provinces in China have shown a significant increase in seismic activity after the earthquake, suggesting widespread triggering by dynamic stresses from the Myanmar mainshock.

Cities Rocked by Intense Shaking

The earthquake caused damaging shaking that extended more than 100 kilometers away from the fault in Mandalay, Sagaing, Nay Pyi Taw, Bago and Shan State, among other locations, Hough said. She noted that the Department of Meteorology and Hydrology in Nay Pyi Taw, which operates Myanmar’s national seismic network, was severely impacted by the shaking.

Shake maps from the earthquake analyzed by Chung-Han Chan of the National Central University in Taiwan indicate that regions intersected by the rupture probably experienced Modified Mercalli Intensity values exceeding VIII, where shaking causes difficulty standing, can move heavy furniture, and cause damage in structures that are not earthquake resistant.

Hiroshi Kawase of General Building Research Corporation of Japan and colleagues presented their research on local site conditions, which they have been conducting since 2014, to help estimate ground motion in the cities of Sagaing and Yangon along the Sagaing fault.

High-Tech Tools Track Disaster

Satellite imagery allowed Xuechun Li of Johns Hopkins University and colleagues develop a comprehensive city-scale map of earthquake effects in Mandalay within days, suggesting their technique could be useful in rapid post-disaster damage assessments.

The Myanmar earthquake also marks the first time a large magnitude earthquake was detected using an array of telecommunication submarine cable networks turned into more than 100 seismic sensors, Mikael Mazur of Nokia Bell Labs reported at the SSA meeting.

Meeting: Seismological Society of America’s Annual Meeting

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