Mw7.7 - 16 km NNW of Sagaing, Myanmar

[davenn]

Mw7.7 - 16 km NNW of Sagaing, Myanmar​

• 2025-03-28 06:20:54 (UTC)
• 22.013°N 95.922°E
• 10.0 km depth

followed by a M 6.4 aftershock

M 6.4 - 18 km S of Sagaing, Myanmar​

• 2025-03-28 06:32:04 (UTC)
• 21.710°N 95.970°E
• 10.0 km depth

from my seismograph here in Sydney, Australia

 

[Astronuc]

That is one heck of an earthquake.

M 7.7 - 2025 Mandalay, Burma Earthquake​

https://earthquake.usgs.gov/earthquakes/eventpage/us7000pn9s/executive

• 2025-03-28 06:20:54 (UTC)
• 22.013°N 95.922°E
• 10.0 km depth

The March 28, 2025, M7.7 earthquake near Mandalay, Burma, occurred as the result of strike slip faulting between the India and Eurasia plates. Focal mechanism solutions indicate that slip occurred on either a north-striking, steeply-dipping, right-lateral fault, or a west striking, steeply-dipping, left-lateral fault. This focal mechanism is consistent with the earthquake potentially occurring on the right-lateral Sagaing Fault that lies in the fault zone that defines the plate boundary between the Indian and Sunda plates.

While commonly plotted as points on maps, earthquakes of this size are more appropriately described as slip over a larger fault area. Strike-slip faults of the size of the March 28, 2025, event are typically about 165 km by 20 km (length x width).

This region has experience similar large strike slip earthquakes, with six other magnitude 7 and larger earthquakes occurring with about 150 miles (250 km) of the March 28, 2025 earthquake since 1900. The most recent of these was a magnitude 7.0 earthquake in January 1990, which caused 32 buildings to fall. A magnitude 7.9 earthquake occurred south of today’s earthquake in February 1912. Within this broad zone of tectonic deformation, other large earthquakes, including a magnitude 7.7 earthquake in 1988, have caused tens of fatalities.

 

[berkeman]

That is one heck of an earthquake.

Agreed! It looks like the damage is extensive, and there are some fatalities and many injuries. Hopefully our DMAT teams and other disaster rescue teams can deploy soon.

https://www.cbsnews.com/news/earthquake-bangkok-thailand-myanmar-strong/

 

[Astronuc]

https://finance.yahoo.com/news/myanmar-quake-death-toll-surges-040431144.html
(Bloomberg) — Myanmar said the death toll from Friday’s powerful earthquake has passed 1,000 amid reports of extensive damage in the second-largest city of Mandalay.

Earthquakes are rare in Bangkok, but relatively common in Myanmar. The country sits on the Sagaing Fault, a major north-south fault that separates the India plate and the Sunda plate.

Brian Baptie, a seismologist with the British Geological Survey, said it appears a 200-kilometer (125-mile) section of the fault ruptured for just over a minute, with a slip of up to 5 meters (16.4 feet) in places, causing intense ground shaking in an area where most of the population lives in buildings constructed of timber and unreinforced brick masonry.

https://apnews.com/article/myanmar-bangkok-earthquake-0a2bd512bca189d034905566605989e9

https://apnews.com/article/thailand-earthquake-bangkok-4fce87aced74b1fc0cf260fb5454d353
The 7.7 magnitude quake struck at midday, with an epicenter near Mandalay, Myanmar ’s second-largest city. Aftershocks followed, one of them measuring a strong 6.4 magnitude.

 

[Astronuc]

Myanmar earthquake's fault rupture exceeded seismic wave speeds, offering rare evidence of supershear​

https://phys.org/news/2025-07-myanmar-earthquake-fault-rupture-exceeded.html

The first studies of the 28 March 2025 magnitude 7.8 Myanmar earthquake suggest that the southern portion of its rupture occurred at supershear velocity, reaching speeds of 5 to 6 kilometers per second.

 

[BillTre]

Myanmar earthquake's fault rupture exceeded seismic wave speeds, offering rare evidence of supershear​

https://phys.org/news/2025-07-myanmar-earthquake-fault-rupture-exceeded.html

Is there a proposed mechanism for supershear?

 

[DaveE]

This is interesting IMO. Definitely above my pay grade, but still interesting.
https://www.nature.com/articles/s41598-022-27159-x

 

[Astronuc]

Myanmar’s Devastating Earthquake in March Split the Earth at ‘Supershear Velocity’​

The southern part of the earthquake’s rupture moved at speeds of over 3 miles (4.8 kilometers) per second
https://gizmodo.com/myanmars-devast...t-the-earth-at-supershear-velocity-2000632109

In a study published July 10 in The Seismic Record, seismologists confirmed previous research indicating that the southern part of the large earthquake’s rupture, or fracture, took place at astounding speeds of up to between 3.1 and 3.7 miles per second (5 to 6 kilometers per second)—at supershear velocity. This likely played a role in the earthquake’s devastating impact.

https://pubs.geoscienceworld.org/ss...4/The-28-March-2025-Mw-7-8-Myanmar-Earthquake

The natural disaster saw around 298.3 miles (480 km) of the Sagaing Fault rupture or “slip,” which is extremely long for a strike-slip rupture of this magnitude, according to the seismologists. By studying seismic and satellite imagery, they determined that the rupture had “large slip of up to 7 m [23 feet] extending ∼85 km [52.8 miles] north of the epicenter near Mandalay, with patchy slip of 1–6 m [3.3–19.7 feet] distributed along ∼395 km [245.4 miles] to the south, with about 2 m [6.6 ft] near the capital Nay Pyi Taw.”

A seismic station near Nay Pyi Taw registered ground motion data that were “immediately convincing of supershear rupture given the time between the weak, dilational P wave first arrival and the arrival of large shear offset of the fault” at the station, UC Santa Cruz’s Thorne Lay said in a Seismological Society of America statement. An offset is the ground displacement that occurs along a fault during an earthquake. “That was unusually clear and convincing evidence for supershear rupture relative to other long strike-slip events that I have worked on.”

See the video and note the crack in the earth just outside the gate to the right.





https://en.wikipedia.org/wiki/Supershear_earthquake#Initiation_of_supershear_rupture