This is because thats basically the upper limit for how tall a mountain can be on this planet.
Comment on Roots of Mother Appalachia
Voyajer@lemmy.world 1 year ago
At their highest it was estimated that the Appalachians were comparable to the Himalayas, with the potential for Everest height mountains along the chain.
uniqueid198x@lemmy.dbzer0.com 1 year ago
ech@lemm.ee 1 year ago
What’s the limiting factor? I assume it’s something with gravity?
MonkderZweite@feddit.ch 1 year ago
I guess, because taller mountains need a bigger/heavier base (Mnt Everest is only a few km over it’s base) and a too heavy base gets “liquid” on, or literally under the plate (it’s magma underneath).
Only guessing though.
uniqueid198x@lemmy.dbzer0.com 1 year ago
Mountain bases can support a lot. Everest is not terribly tall from its base, true, but Denali is 5500 meters from base to top and Mauna Kea rises to 10000 meters over base.
Its also a bit of an incorrect picure to think of the interior magma as a liquid. It can flow, but it can also sieze up or crack. Its an in-between, like corn starch and water.
uniqueid198x@lemmy.dbzer0.com 1 year ago
Its indirectly gravity. The taller the mountain, the more eroding force can be pleced on it. Water travels faster and therefore cuts deeper.
Everest is still uplifting fairly quickly at 1mm a year, but its also eroding at roughly the same pace and won’t get significantly taller than it is now. The same is true for the rest of the Himalaya as well, the whole range is eroding at a very high pace.
The Himalaya are home to some very spectacular canyons, including the largest canyon above water. The geology there is on full display and incredible.
768@sh.itjust.works 1 year ago
Plate tectonics and isostasy: Ocean ridges can only push so much and the denser a mountain range is, the higher the stress on the crust and mantle material.
www.youtube.com/watch?v=3rk2jx3eRDE
I guess this only explains the positive constraints of orogenesis.
wildginger@lemmy.myserv.one 1 year ago
They are also only half of the original mountain range, which was split when pangaea split apart.
The other half is now resting across europe, I think along the northern range.
Serisar@feddit.de 1 year ago
The scottish highlands are the continuation of the appalachians. Those long striations you can easily see on heightmaps is pretty much the most easily noticeable features of both ranges.