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The Tectonics Behind the Myanmar Quake

36 points by rbanffy - 6 comments
sleepytimetea [3 hidden]5 mins ago
I liked the photo that one of the quoted seismologists, Zhigang Peng from Atlanta, supplied to the author of this article - which depicts the seismologist standing in front of a sign marking the San Andreas fault on a visit to California. Its just the kind of photo a visiting seismotourist would take !
RcouF1uZ4gsC [3 hidden]5 mins ago
> The belt’s tectonic activity has birthed many of the world’s most impressive mountain ranges, including the Alps, the Atlas Mountains, and the Himalayas.

I though the Himalayas were formed from the Indian subcontinent slamming into the Eurasian land mass?

adrian_b [3 hidden]5 mins ago
Simultaneously with India, also Africa and Arabia have collided with Eurasia.

So the Himalayas have formed at the same time with a great number of mountain ranges, from the Atlas and the Pyrenees at the Western extremity, passing through many other mountains, e.g. the Alps, the Carpathians, the Caucasus, the Hindu Kush, the Pamir etc., until the Himalayas at the Eastern extremity.

See:

https://en.wikipedia.org/wiki/Alpine_orogeny

jofer [3 hidden]5 mins ago
It might help to think of it less as "Indian subcontinent slamming in" and more as the "Tethys ocean basin closing".

India being pulled away from Africa/Madagascar and eventually beneath the Eurasian continental crust is all related to the closing of the Tethys. ...This is a lot easier to explain with pictures...

If it helps, remember that continents are just lighter and thicker "rafts" of stuff. They're not plates themselves. They're often attached to oceanic crust as part of a plate. When one side of that oceanic crust becomes cold and thick enough to start to subduct, the entire plate gets pulled along.

knd775 [3 hidden]5 mins ago
You don't consider that "tectonic activity"?
aaron695 [3 hidden]5 mins ago
Here's a (2014) article talking about it - https://doi.org/10.1002/2013JB010762

"One notably (and perhaps ominously) quiet section of the fault is the 220 km long Meiktila segment, between the large city of Mandalay and the new capital of Naw Pyi Daw. This long quiet section separates a southern cluster of ruptures in 1929 and 1930 from a northern cluster between 1931 and 2012. The length of the Meiktila segment implies that it is capable of producing an earthquake as large as Mw 7.8 to 7.9, if it ruptures all at once [Wells and Coppersmith, 1994; Blaser et al., 2010] (Figure 22 and Table 4).

We speculate, on the basis of sparse historical records of shaking, that the 1839 Ava earthquake may have resulted from the failure of Meiktila segment, in conjunction with the Sagaing segment, its neighbor on the north. If the Meiktila segment has been dormant since then, and the fault is fully coupled down to a depth between 12 and 15 km, as Vigny et al. [2003] and Socquet et al. [2006] suggest, then accumulated slip potency on the Meiktila segment after 1839 is enough to generate a Mw 7.6 earthquake."