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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Do tidal forces affect subduction?
I know subduction in plate tectonics is mainly density driven.
Probably a hypothetical question, but can weaknesses caused by tidal forces have an influence on the start of a subduction zone? Would ...
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How does slab pull work?
My understanding is rocks are very weak in tension. How can a subducting slab "pull" an entire lithospheric plate behind it?
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Will Nanga Parbat eventually become taller than Mount Everest?
It is a well-known fact that Mount Everest, a Himalayan mountain whose summit stands at an elevation of $8,848.86 \text{ m }(29,031.7\text{ ft})$ above mean sea level, is currently the tallest ...
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Are the oceans rising or the continents going down? How can we know?
The century old sustained rising of oceans, at a rate of 2-4 mm/y, remains a unexplained phenomenon; there is no correlation with temperature variations, so it is not due to the thermal variation of ...
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Accuracy of continental drift maps?
I was looking up maps of continental drift through history and I noticed something that seemed off to me. Madagascar seems like it very obviously must have separated from what is now southern ...
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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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Is Mt Everest the highest mountain peak we know of in earth’s history?
I’m currently reading John McPhee’s Annals of the Former World, which is discussing plate tectonics. He often gives figures for uplifts at subduction zones measured in tens of thousands of feet.
This ...
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Why hasn't all the water on earth evaporated and been frozen at the poles?
It seems like over a long enough time scale, if the surface temperature of a planet varies between perennially below freezing and occasionally above freezing, that all of the water on the planet would ...
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If the Pacific Ocean is 750 million years old, Why can't oceanic crust be older than 200 million years?
Since the first rocks of the pacific Ocean plates solidified from magma coming out of a rift 750 million years ago, shouldn't they be much older than the maximum age of oceanic crust (around 200 ...
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What determines the shape of tectonic plates?
I understand plate tectonics at approximately the level of the Wikipedia entry, but I have not idea what factors determine the particular locations of the plate boundaries.
Do we have a model for the ...
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Question regarding the breakup of India from Eastern Gondwana [closed]
I wanted to ask this question as it relates to a project I am working on. In this "timeline" when India broke away from Gondwana the Indian Plate took a small piece of land from Eastern ...
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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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If there was no Glaciation, what would the USA great Lakes look like?
I guess, what they looked like before Glaciation could also work as an answer.
Everything I have seen on the lakes only mention their post-glacial forms even when some of them mention that they formed ...
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What would Canada's larger lakes (Bear, Great Slave, Winnipeg, and Athabasca) look like without glaciation?
Canada's larger lakes (minus the "Great Lakes" that it shares with the USA) sit on the edge of the Canadian Shield (https://www.youtube.com/watch?v=2TmSP02zPaI). On the other side of the ...
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How Do Plateaus Really Form?
Any time I hear the word "plateau", I usually associate it with the tallest in the world, Tibet. Anyone who looks closely at a map will see that the southern line of the plateau parallels the ...
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Is the Pacific Plate composed of smaller plates?
The question, Why are all lower mantle plumes under oceans? has the following diagram
which was taken from Wikipedia Commons.
About half of the large red dots occur on or near the boundaries of ...
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Is it inaccurate to describe Earth's mantle as "soft and plastic"?
The Earth's mantle, away from the occasional magma chamber, is solid. But it flows over time and so is described as "pliant", "hot chocolate", "toothpaste", etc.
Glaciers ...
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What is the maximum intensity with which an earthquake can struck Chitral city in Northern Pakistan?
I am working on a disaster response logistics case study in which I am using Mi-17 helicopters for transportation of relief to the affected areas in main Chitral city.
In this regard, I want to ...
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Do subducted continents rise up again through ridges?
Layman here, sorry if this is a stupid question. I have a geology friend who recently told me that plate tectonics is like how warm milk cools on top to form thin solid layers. The convection cells in ...
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Is the earth crust under the pacific ocean heavier than in the rest of the planet?
Please bear with me, since I don't know much about geography or geology.
I was looking at an earth globe and noticed the pacific ocean covers virtually half of the planet (more or less). How is 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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What forces plays the role in order to subduct the denser tectonic plate under the lighter plate?
I am a 10th grade student and I don't know much about geology but I'm learning about subduction online. It's always mentioned that the denser plate gets subducted under the lesser denser plate. I want ...
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What is the tectonic setting for the formation of the Great Dividing Range in Australia?
Australia's Great Dividing Range is the largest mountain range on the continent, running down the length of the eastern part of the continent, as shown in the Geoscience Australia map as a dark line, ...
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Why was the initial theory of plate tectonics so controversial?
I have been set the task of researching plate tectonics, specifically:
"Why was its discovery so important in its time and controversial?"
I do not need a long answer, although more detail is always ...
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If among oceanic crusts older means heavier, then why is old continental crust lighter than new oceanic crusts?
When we consider two oceanic crusts, the older oceanic crust is heavier and the newer oceanic crust is lighter.
But when we consider two crusts, one continental and the other oceanic, continental ...
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Why is basalt denser than granite?
If lava is nothing but magma breaking through the earth's surface, then why is basalt more dense than granite?
I understand that something happens during the cooling process, but cannot find any ...
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Do these rock layers correspond to different years?
This is a close picture of a cliff in the north coast of Spain. As you can see, the rock is composed of multiple thin layers, alternating between dark and light materials. Could this be the result of ...
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Is the Theia impact partly responsible for the distribution of mantle plumes?
I was looking at a map of the distribution of mantle plumes, and was wondering if they could be residual material that was either brought here or affected by the Theia impact.
It seems to me that this ...
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Can a tectonic plate subduct under one plate while another plate subducts under it along the same boundary?
At a triple junction plate boundary there are three tectonic plates meeting. We have plenty of examples of these boundaries on Earth, notably the Afar Triple Junction, Mendocino Triple Junction, and ...
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How is felsic magma produced at island arcs?
I previously believed that continental crust owes its lower density to the partial melting of oceanic crust; the mantle would partially melt at mid-ocean ridges to produce basaltic crust, and when ...
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Google Earth type, online plate-techtonics demonstration over time
I once found an site on the internet that displayed the continents in a Google Earth type setting where you could spin, zoom and navigate around the Earth but in different geological time periods. You ...
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Speculative Plate Techtonics - Resolving intersecting subductions
I'm working through Artifaxian's (https://www.youtube.com/watch?v=AzD_WVsEIRM) series on using gPlates to make tectonic history. I've run into the place where I have two subduction ridges about to ...
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Does the Moon affect earthquakes?
Does the Moon, through factors like its location (if it is at an apsis i.e closest point or furthest point in its orbit) or some changes in density, affect earthquakes on the Earth?
Earthquakes are a ...
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Why does a subduction zone produce a serpentinization diapir rather than volcanism?
The classic Troodos Ophiolite in Cyprus has been uplifted by a 'serpentinization event'. Upper mantle (peridotite) has been serpentinized creating a buoyant diapir. This has uplifted the ocean crust ...
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Why are the supposed-to-be results of collision and/or subduction formed in an area where collision and/or subduction didn't happen?
Please correct me if I have said something wrong, as it might be the answer to my question. Also, these are all the things that I've learned through self-studying, so I might have been mislead.
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Would the US East Coast rise if everyone living there moved away?
I watched a documentary about research on the coasts of Greenland where the sea level has fallen. According to the research, this is because a lot of the glaciers have melted, resulting in less weight ...
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Least equatorial ( and tidal) bulge consistent with modest amounts of water in polar regions
In World Building I asked a question about the climate of an hypothetical planet.
There Vogon poet said that
Everyone above 10° latitude will be in permanent drought
Considering that there were no ...
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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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Origin of the continents
Visiting from WorldBuilding SE. Someone recently asked a question that dusted off an old theory I had once had, so I started digging. Sadly I could find little more on the topic than the first time I ...
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Would obliquity and precessional changes of Earth affect the accuracy of GPS-based measurement of tectonic movements?
The rate and direction of tectonic movements can be measured by comparing the coordinates of the same GPS receiver over time. The coordinates are obtained using trilateration.
All materials I could ...
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Does the Plate tectonics contradict the theory of continental drift?
According to the theory of continental drift, South America and Africa was so closed to each other that the convex triangle of South America meets the concave hollow of Africa.
Source: usgs.gov; ...
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How do tightly packed plates move in the theory of plate tectonics?
Here are two questions I had ever since I first heard about plate-tectonics.
How can the plates move? Before you suggest me some page to read about plate movement mechanics, let me clarify that I am ...
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Is there any research on the relation of asteroid impacts and hot-spots?
In a new video by Atlas Pro on Hawaii linked below, he indicates a curious observation: Most hotspots antipode’s have sign’s of heavy impacts from asteroids.
He postulated that the force of these ...
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Are oceanic plates or continental plates heavier?
If you take a cilindrical section with radius 1 meter of both kinds of plate, which will have a larger mass?
My guess is that continental plates are heavier than oceanic plates, because they are more ...
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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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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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What is causing the crustal extension exhibited by the Basin and Range province in western North America?
Is there any link with the subduction of the Farallon Plate and the associated spreading center?
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Why are there no volcanoes where continents collide with each other?
I understand that volcanoes occur where oceanic crust is subducted under continental crust such as the Andes. However, they don't occur at places like the Himalayas and Alps where continental crust is ...
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Why is the Colorado Plateau so stable?
The Colorado Plateau somehow has avoided all the tectonic activity around it over hundreds of millions of years. Is it just luck, or is there something about that chunk of crust? I have toured the ...
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Can continental plates collide and fuse together without an orogenic band or magmatic arc or at the junction?
I have seen this diagram on Wikipedia (link below). It shows that some North American mini-plate boundaries are orogenic bands and some are magmatic arcs, and I think those correspond to continent/...
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