New answers tagged plate-tectonics
1
This is more a problem with how you are trying to categorize things than any concrete problem.
A "plate" is not a completely hard and fast concept, there is some interpretation involved, it is a way of categorizing a group of natural objects with similar properties. When continental crust merges they do not become homogeneous, much like how individual ...
0
The question of where are the Oiler poles are right now is not of particular interest.
I find it curious that the one for the North American plate lies roughly close to the famous "Muertes Archipelago" ;-)
1
Adding to the answer, the cold and dense slab that pulls the oceanic crust behind it down into mantle may rip off and sink down, causing a "sudden" change in buoyancy of the anyway less dense overlying continental crust. That way we have mountain ranges that quite well mark the main subduction zones on earth.
Edit: ok, expanding a bit on the buoyancy thing:
...
1
New(ish) work on the matter:
https://www.nature.com/articles/s41598-018-33823-y
tl,dr: "Modern style" plate tectonics may be (at least) as old as 2.2Gy, probably having started 2.5Gy.
Expanding as requested:
The paper is not paywalled. It is about a metamorphic (by temperature and pressure altered) rock that fits in a regime that is typically connected to ...
3
The driving forces of plate tectonics has long been debated. Several mechanisms have been proposed, mainly ridge push, mantle drag, and slab pull (see this page from the British Geological Survey). However, there is now a good agreement that slab pull is the main driving force of plate tectonics. It means that it is the subducting plate which controls the ...
1
As you suggested in your question, one of the things that slows plates down is friction with an adjacent plate. The force that drives them forward is the force of the mantle plume or plumes that split them off in the first place. A very large plume of magma rising from far below sometimes causes a plate to break off from a larger one, and a rift valley ...
5
When the subducted oceanic plate slides beneath the continental crust, it causes crustal thickening and sometimes crustal folding. In addition to this, rising plumes of magma are created when the oceanic plate is forced down into the mantle. These are all orogenic (mountain building) processes. We also have mountains built by volcanoes.
The friction created ...
2
The jaguar is a close relative of the Asiatic leopard and must have had a common ancestor within the last 5 million years. The South American tapir is obviously closely related to the Malayan tapir and must also have had a common ancestor within he last 5 million years.
While the first statement is more or less correct, the latter is not. The Asian and ...
0
It depends where the mountain is. Usually it is plate tectonics or volcanism that makes mountains higher, but in some circumstances it could be erosion. During the Ice Age,there were a couple of kilometres of ice pressing down on northern Britain. When the ice melted, it did so quite rapidly in geological terms. The ice not only disappeared, but torrents of ...
7
This actually does happen, a feedback loop between the Himalayas and the Indian monsoon.
The Indian Plate is actively shoving itself under the Eurasian Plate, creating the Himalayas.
At the same time, monsoon storms come up against the southern side of the Himalayas. The high mountains enhance the storms' rainfall, and the mountains erode much more on ...
4
you are missing a big factor, the plates are not moving due to the momentum of an initial impulse. They are being actively moved by the push and pull of mantle convection. Much like how icebergs are pulled along by ocean currents. the iceberg analog however breaks down because icebergs melt before they can do much complex interaction, where as continental ...
Top 50 recent answers are included
