Questions tagged [plate-tectonics]

The theory that Earth's outer shell is divided into several plates that glide over the mantle, the rocky inner layer above the core.

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Is there a geological explanation for the recent Mammoth tusk discovery 185 miles off the California coast?

A recently publicized discovery of a Columbian Mammoth tusk located well of the coast of California in quite deep water made me wonder if geological conditions 100,000 years ago can explain how it got ...
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What role does the hydrosphere play in tectonic plate convection?

I need to do a "how do different 'Earth's spheres' interact with each other" and I'm trying to figure out how the hydrosphere would affect the lithosphere if the ozone layer were to ...
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Tectonic plates terminology

I have a very basic doubt regarding what the tectonic plates mean. In Wiki article Subduction is defined as: Subduction is a geological process in which the oceanic lithosphere is recycled into the ...
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When did the proto-Himalayas become non-volcanic?

In the normal course of events, when continents move toward each other, at least one coast will be associated with a subduction zone and corresponding volcanic activity. When the Indian subcontinent ...
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Is there any source that shows all of Earth's terrain changes from Pangea to present?

I teach a class on my state's history to middle school students. Our textbooks do not cover much historical geology, but its a subject students are fascinated in, and feel needs to be added. I want to ...
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Why does the ocean floor look so scratchy?

Why does some part of the ocean floor look so scratchy? If you look at Google Earth image of the Indian ocean floor, especially the area south-west of Sumatra, it looks like some cosmic beast ...
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Slab-breakoff - always connected to continent/continent collision?

The question came to me when pondering the Andes: Is a slab-breakoff always connected to the transition from subduction of oceanic crust to a continent/continent collision? Current understanding is ...
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How do the Andes get so high?

I'm interested in the limiting factors on the height of mountains. There is a very good explanation at https://www.quora.com/How-tall-can-a-mountain-become-on-Earth-Neil-deGrasse-Tyson-says-Mount-...
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What will happen to the Indian plate after it slides under the Eurasian Plate?

What will happen if the Indian Plate is done sliding under the Eurasian plate? I hypothesied some possible answers. Tell me the answer and if my hypothesis is not correct. Most likely to least. It ...
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Farallon plate subducting under North American plate: is it a factor in "the next big one"?

I am a writer, not a scientist of any kind. I live in the SW AZ desert (USA), so we get earthquakes from time to time. I grew up in southern CA, right next to the San Andreas fault, so I have a ...
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How many supercontinents have there been? [duplicate]

With plate tectonics, supercontinents split up into smaller continents, and then the smaller continents get mashed up together to form a new supercontinent. There used to be a single supercontinent ...
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How on "Earth" can you make all those measurements of Earth forming?

This question is a result of recent news that Earth had a "boring billion" years in which mountains ceased to grow, and subsequently hindered life evolution. The article went on to give ...
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Why are there no subduction trenches on continental land?

The ocean has some of the deepest locations on earth, typically caused by subduction zones. Why are there no subduction trenches on land?
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What happens when a mid-ocean ridge sub-ducts underneath continental crust?

I'm aware that oceanic crust always sub-ducts to continental crust, but surely the geologic forces pushing the ridge apart in the first place isn't just going to turn off, right? Any answers would be ...
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Is COMSOL Multiphysics good for subduction CFD modelling? Are there alternatives?

As a beginner for CFD modelling of plate subduction, I heard comsol to be a good software. Can anybody suggests alternatives and the demerits of using COMSOL Multiphysics? Thank you.
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Can garbage be sent into the (near-)center of the world?

I've been thinking about how difficult it is to eliminate toxic chemical waste -- it usually needs high temperatures and pressures. So: would it be feasible (and maybe cheaper) to send it into the ...
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Will California become a subduction zone in the distant future

California is one of the few places in the world that lie on a transform fault. My question is why considering the fact that North American Plate is moving westward shouldn't California be a ...
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Is it possible for Mexico to have a magnitude 9 earthquake?

Everyone has heard of the Cascadia Subduction Zone and the potential threat it poses. However, I have heard nothing about The Cocos Subduction Zone, even though it caused a devastating earthquake over ...
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Nickel question - non geologist me

Why are there no giant nickel porphyry deposits like those of copper, or SEDEX deposits, like those of zinc? Why is all the nickel found in direct magmatic intrusions from the mantle to the surface? ...
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Seismic activity in the UK [duplicate]

On 8th September 2020 there was a magnitude 3.9 earthquake here in the UK at 51.817°N 0.665°W which is approx. 10km/6.2miles east of Aylesbury or roughly 50km/31miles east of Oxford. This got me ...
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Why aren't there ultra acid igneous rocks?

In my study, I found that in volcanoes when the magma is going up it formed different types of rocks. There are basic, acidic and ultrabasic. My question is why isn't there ultra acid igneous rocks ...
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Why is Europe still considered a continent(along with Asia)? [closed]

It is true that there are multiple definitions of a continent. But it is also true that Europe fails to satisfy any of them. One of the boundaries between Europe and Asia was chose arbitrarily(the ...
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What was the Earth's continent's positions 10000 years ago, or 11700 years ago, AKA when the late Pleistocene epoch was coming to an end?

In many articles online, geologists and geographers have described and depicted the theorized locations of all our continental plates with great detail and illustration, providing pictures, time-lapse ...
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Why aren't the Hawaiian islands a continuous strip of land?

My understanding is that the Hawaiian islands were produced as the Pacific plate moved over a stationary hot spot, which sent magma burning up through the plate as it passed over, forming a trail of ...
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What sort of a plate is the Sunda plate?

I have read that the islands of Sumatra & Java have resulted from the subduction of oceanic crust of the Indo-Australian plate beneath the Sunda plate. I want to know whether this boundary is ...
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Amount of Distortion at Continental Collisions

Something that I've wondered for a while now - When continents collide, how much of the landmass gets distorted by the collision before it settles? To perhaps give a clearer idea of what I'm talking ...
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Where and how big was Sicily between 5 and 1 Ma ago?

Sicily is a geologically complex island which seems to have been extensively studied geologically and from a tectonically point of view. There are an overwhelming number of papers dealing with the ...
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Why isn't Iberia a tectonic plate?

I usually read that Iberia is a subplate, while India is a plate. But it was a plate at the beginning of the Alpine Orogeny: Source: wikimedia.org Description: Tectonic map of southern ...
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How long for tectonic plates to develop from a planetary, molten planetary surface?

On Earth or an Earth-like planet, how long does it take for a molten surface to solidify into planetary crust, and how long does it take for that crust to develop into tectonic plates?
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What initiates the plumes which create oceanic hot spots? [duplicate]

What causes the large and very long lasting magma plumes which rise up from the mantle and create a hot spot such as the ones which built the island chains of Hawaii and Galapagos? The volcanic ...
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Could the speed in which the plate is moving affect how quickly mountains rise?

In an episode of History Channel's How the Earth Was Made, there was a remark when India left the rest of Gondwana 80 million years ago only to collide with mainland Asia 50.5 million years ago. The ...
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What were the geometric coordinates of the Chicxulub impactor 66 million years ago?

At the moment around mexico we can find the leftovers of the Chicxulub impactor which could have extincted most dinosaurs. But 66 million years ago was after the breakdown of Gondwana. So back to ...
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How Can Adjacent Parts of an Oceanic Plate be Subducted in Different Directions?

It is claimed by some that the reason for gaps in chains of volcanoes generated by plate subduction is that some parts of the plate dive deep into the mantle and generate magma plumes, while other ...
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Cratonization - how did the Archean cratons form?

Before the onset of modern style plate tectonics and the Wilson cycles in the late Archean, it is thought that smaller units of continental crust, called cratons, roamed the oceanic crust over a more ...
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Gaps in locations of volcanos (Peru & Chile)

The figure below is taken from Reath, K. et al. (2019) A couple of things can be seen from this representation Volcanism seems to be strongly correlated with subduction zones, in this case the Nazca ...
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What causes some plates to move faster than others?

Why do some tectonic plates move faster than others? Is it due to friction between the plates, the driving forces on the plates, or both? If it is driving forces, what makes the driving forces on ...
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How does a subduction zone form mountains?

When an oceanic plate goes under a continental plate are the resulting mountains a result of the melting and then rising of the oceanic plate or are the mountains formed by the continental plate being ...
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Migration Routes for Animals from Asia to America [closed]

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 ...
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Does erosion make mountains become higher?

Recently at the American Museum of Natural History in New York, I saw a display set that claimed erosion makes mountains rise higher, counterintuitively. The explanation was that the material removed ...
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Do tectonic plates "float" over the mantle and "collide" like icebergs?

I'm always hearing about tectonic plates as large chunks of crust floating on the mantle just like boats. In timescales of millions of years they move and even collide. But I'm starting to think this ...
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What is the impact of divergent tectonic plates on old mountain ranges?

I found this question, which is similar to what I'm wondering, but my question is slightly different: What happens if a new divergent boundary forms in a way that bisects a mountain range, especially ...
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where are the poles of rotation of the tectonic plates located?

Euler's "fixed point" theorem ... can be stated as: The most general displacement of a rigid body over the surface of a sphere can be regarded as a rotation about a suitable axis which passes ...
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How have Farallon plates's remnants stayed as they were inside the mantle?

Why hasn't the subduced Farallon Plate's materials been recycled? Why do they appear to be flowing in a molten state?
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If two adjacent tectonic plates are moving in the same direction, is there significant interaction at the boundary?

If two adjacent tectonic plates are moving in the same direction, is there significant interaction at the boundary? Is it just a convergent boundary if one moves faster and "catches up" with the other?...
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Does subduction of continental crust happen at continental-continental convergent boundaries?

What exactly happens at a continental-continental (cc) convergent boundary? I read myself through the web for the last few days and what I came up with is that such a boundary will start as an oceanic-...
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How is the difference in crust and mantle composition explained?

We know that the composition of the crust is SiAl and SiMa and the one of mantle is mostly ophiolites, but why? Which are the geological processes that make this difference exist?
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Is there a place where the sea floor descends into the mantle of the earth?

My understanding of plate tectonics is that in the middle of the oceans magma rises from the mantle of the earth, cools and then spreads out, building up the sea floor. These places are pretty obvious ...
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How can linear oceanic ridges (like the East Pacific Rise) be explained by single point mantle plumes?

I'm a bit confused about how divergent boundaries between tectonic plates work, or just why plates move. I've read that these ridges that are in the place of divergent boundaries are created when ...
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Which ocean is going to be swallowed by the Supercontinent Cycle, Atlantic or Pacific?

The register shows several supercontinents have been formed on Earth's History: "The most recent supercontinent, Pangaea, formed about 300 million years ago (0.3 Ga). There are two different ...
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Why do ophiolites obduce upon Continental Crust?

Oceanic Crust is more dense than continental one. The margin between both types of materials can be passive or develop a subduction zone, where Oceanic Crust sinks under continental one. I know there ...