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Questions tagged [crust]

For question dealing with the Earth's crust or other planemos.

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1 vote
0 answers
19 views

Mountain formation and stress release?

I have been studying mountain formation, and have some questions about how orogeny and plate stress release are related... Does orogeny contribute to the release of accumulated stress within the ...
2 votes
1 answer
465 views

Does this support Hapgood's Earth Crust Displacement Theory?

I'm no Geologist by any standard but I'm quite intrigued by what goes on below our feet. I came across this article that states there's a new or (confirmed) partially melted layer in the athenosphere (...
1 vote
2 answers
614 views

Why does the Earth's crust have more aluminum than magnesium while the Sun has more magnesium than aluminum?

Magnesium represents 0.07 % of the composition of the Sun's photosphere while aluminum represents 0.006 %. Therefore, there is much more magnesium than aluminum in the Sun's photosphere. But the same ...
3 votes
1 answer
440 views

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 ...
2 votes
0 answers
78 views

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 ...
3 votes
1 answer
108 views

If the universe (and our galaxy) has about twice as many oxygen atoms as carbon ones, why does Earth have 300 times as many oxygen atoms as carbon?

A (relatively) recent 'Sky & Telescope' magazine feature story mentioned how little carbon the Earth has, and how some scientists' models predict we should somehow have even less.... So I looked ...
1 vote
0 answers
61 views

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 ...
2 votes
1 answer
44 views

Displacement-Length scaling relationship on extraterrestrial faults

Faults on Earth share a similar displacement/length ratio of around 0.03 which scales from very small faults to very large faults. Would this apply to faults on other planets and if so, are there any ...
1 vote
0 answers
40 views

When was the thickness of the Earth's crust calculated?

When was the average thickness of the Earth's crust first calculated or estimated? What did scientists know about the thickness of the Earth's crust before the 20th century? In what interval(s) fell ...
4 votes
5 answers
163 views

Is There a Correlation Between Earthquake Magnitude and the Deformation Observed in the Rock?

I've been doing a little geology research. One of the topics that I noticed was the existence of "deformations" that appear in the rock layers if an earthquake has occurred. Smaller ...
4 votes
1 answer
641 views

What would happend in distant future if we didn't extract fossil fuels

I'm sorry if that is stupid question. Geology is not my thing, but I'm curios about this. Let's assume that mankind has never extracted fossil fuels (or existed in the first place) and for millions ...
4 votes
2 answers
249 views

Why is there gold in the earth's crust?

I would naively assume that when the earth was formed and still molten, all the heavy stuff such as gold would have sunk to the centre, so almost nothing would remain in the earth's crust where humans ...
7 votes
2 answers
749 views

Why should there not be water deep (e.g. below 6 kms) in the Earth's crust?

In 1970, the USSR began drilling at the Kola Super-deep Borehole. The target depth was 15,000 meters; The stated areas of study were the deep structure of the Baltic Shield, seismic discontinuities ...
6 votes
3 answers
4k views

If the Kola Superdeep Borehole were opened today, what would come out of it?

The BBC News article The Deepest Hole we have Ever dug says: This is the Kola Superdeep Borehole, the deepest man made hole on Earth and deepest artificial point on Earth. The 40,230ft-deep (12.2km) ...
10 votes
2 answers
1k views

Composition of Martian Crust

Does the composition of the crust of Mars roughly correspond to that of the crust of Earth. That is, is the elemental abundance in decreasing order silicon, oxygen, aluminum, etc.?
8 votes
0 answers
83 views

By how much did the Earth's diameter decrease due to cooling, if at all, since it was formed?

The answer to How long until Earth's core solidifies? question cites an estimation that the Earth (as a planet, not the surface of it) has cooled down by about 250K since it was formed. The question ...
13 votes
2 answers
1k views

Why does Earth have two kinds of crusts?

Why does Earth have two clearly differentiated kinds of crusts, namely continental and oceanic? How did they differentiate initially and why don't they get mixed up over time?
5 votes
1 answer
160 views

Is there a seismic discontinuity between the lithosphere and asthenosphere?

I've been learning about seismic discontinuities, mainly the 5 defined ones - Conorod discontinuity, Mohorovicic discontinuity, Repetti discontinuity, Gutenberg discontinuity, and Lehmann ...
3 votes
0 answers
918 views

Crustal age global map

I've been searching for a map depicting the age of each part of the crust for a long time. I'm not a geologist but I'm a physicist so I would like to know about the most up-to-date and accurate ...
5 votes
2 answers
658 views

How likely are caverns inside the mantle?

Almost everyone wrongly assumes that the Earth's mantle is liquid, but it isn't (only the outer core is). Is it possible then that there are hollow spaces within the mantle, similar to caves in the ...
6 votes
2 answers
3k views

If people aim to reach the mantle, why don't they just use volcano craters?

Once in a while aspiring people aim to drill through the Earth's crust to reach the mantle, but why do they want that when the mantle is actually on or very close to the surface in volcano craters? ...
5 votes
2 answers
3k views

What's the official reason why it became so hot in the Kola borehole?

The Kola drill went 'only' a third the way to the mantle, so its deepest point was still closer to the surface than to the mantle. Why did the drillers experience 180 °C when so deep, where did that ...
20 votes
4 answers
6k views

Do fossil fuels insulate the crust from the Earth's interior?

I was doing a project for my English class, and I came upon the article Energy conservation in the earth's crust and climate change. I can't view the full text of the article, but the abstract piqued ...
1 vote
0 answers
31 views

If all liquid stuff inside the Earth turned solid, what would be the effect?

There are parts inside the Earth (near the core) that are liquid. Presumably causing the Earth's magnetic field (though there are celestial bodies that are completely solid while they have a magnetic ...
13 votes
1 answer
677 views

How is abundance of elements in the Earth's crust estimated?

In an quiz app I surprisingly learned that aluminium has a larger abundance then iron. When researching this on Wikipedia, I found this article, which also had the comment: Note that numbers are ...
3 votes
1 answer
127 views

Term for the Process of the Early Earth's Crust's Changing Mineral Composition

In the book, Story of Earth-The First 4.5 Billion Years, From Stardust to Living Planet, by Robert Hazen, Chapter 3: He discusses the changing mineral composition of the early Earth's crust from ...
7 votes
1 answer
412 views

Why is calcium so much more abundant in/on Earth's crust (and oceans) than it is elsewhere? (relatively speaking...)

Inside the entire Earth as a whole, and throughout our Solar System and galaxy, etc., magnesium is at least 14 times (or more) as common as calcium, atom-per-atom. But, on Earth's crust and oceans, ...
7 votes
3 answers
2k views

If the Sun disappeared, how long would it take for the Earth to freeze beyond excavatable depths?

If the Sun disappeared How long would it take for the earth to freeze beyond excavatable depths? How long until it freezes to the core? (Is this different than without removing the Sun?) Would we be ...
5 votes
2 answers
1k views

How do the different densities of the oceanic and continental crust affect earth's outer shape?

I am currently reading a textbook and I am slightly confused at a paragraph that deals with some general facts about earth's outer shape. It mentions that the density of the continental crust is ...
4 votes
1 answer
372 views

Are the precious metals (silver, gold, platinum) present everywhere throughout the Earth's crust at least in the trace quantities?

Do some rocks, soils, sands or waters exist that contain fewer than one atom of gold per cubic meter or tonne of their mass?
3 votes
1 answer
2k views

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 ...
2 votes
2 answers
520 views

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 ...
20 votes
4 answers
16k views

What is the deepest we have ever gone into the Earth?

I remember Journey to the Center of Earth and wonder: What is the deepest in the Earth surface or below sea level we have traveled either by foot, sub, drill or camera?
3 votes
0 answers
21 views

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 ...
5 votes
1 answer
1k views

Why is there so much more silicon than carbon in the Earth's crust?

Some arguments I've seen about the viability of silicon-based life involve the relative abundance of silicon vs carbon. In the universe as a whole, there's a lot more carbon than silicon around. Yet, ...
4 votes
1 answer
60 views

Do there exist reasonable numbers on the density/radius/mass of the various geological layers of the Earth?

I've been doing some math on the radius of the core (inner core in particular), and I keep getting what look like nonsense results. The composition is supposedly nearly all iron, close enough to it ...
7 votes
1 answer
117 views

Is salt accumulating over time?

The rainfall leaches salts (Mg,Na,Ca,K,.., Cl) from weathering rocks, where those ions were freed from chemical bonds by sunlight, acidic water etc. The runoff eventually goes into the oceans, where ...
2 votes
1 answer
1k views

Does crustal thickness have anything to do with how life existed and sustained on Earth? [closed]

The original question that was put on hold "If the crust were the thickest layer of Earth, what effect would its thickness have on organisms?" was actually one of those 'counterfactual question' ...
0 votes
2 answers
3k views

What if we detonated the entire worlds nuclear supply in the center of the earth? [closed]

What would the effects of detonating every single nuclear bomb currently in existence at once in the center of the earth? Would the earth simply explode into bits? Would the heat have some sort of ...
1 vote
1 answer
273 views

Why did sinkholes emerge in Pakistan?

Here is a video. Why did the sinkhole emerge in Pakistan? Is this because of the heavy exploitation of groundwater? What could be the solution? Reference In pictures: Chaos as rain continues to ...
5 votes
2 answers
540 views

Why is lithium so unevenly distributed?

According to the US Geological Survey, nearly all of the world's lithium reserves are in Chile/Argentina, China, and Australia. Why is this? Lithium seems to be mostly harvested from brine pools, so ...
-4 votes
1 answer
1k views

Can a shock wave travel around the Earth's curvature?

Can an explosion be felt in the ground on the opposite side of the Earth like from an asteroid? Would planes in the air on that side of the Earth be able to survive? Does the shock waive follow the ...
15 votes
3 answers
13k views

What do continents "lay" on?

It's a simple question.. What do continents "lay" on? Do they float on water? or are they huge bodies that "emerge" from the sea floor/bed? are they connected to the bottom of the oceans? Hope the ...
5 votes
0 answers
98 views

On which software can I simulate landmass collisions?

Such as in 3D simulations of vehicule crashes but this time with huge rocks or bodies of water (continental plates). I need to be able to set the properties of the material (density, size etc) and see ...
8 votes
0 answers
81 views

Are there any signs on the Earth's surface that indicate a shrinking iron core? [duplicate]

It appears that Mercury shows some cracks on its surface that were not caused by moving tectonic plates but by shrinking due to the inner metal core cooling. The Earth is also cooling down, but are ...
6 votes
2 answers
3k views

Why are most minerals so rare?

There are 4,660 known minerals, so why are most of them so rare? Is it to do with the structure of minerals?
3 votes
2 answers
131 views

Need help understanding what an "isostatic model minimizing crustal deviatoric stress" means

Despite the background information coming from another body besides the Earth, the terms I would like to understand are historically geophysical in nature. Background: I just read today's news "...
1 vote
0 answers
106 views

Which places in Earth's crust have the highest concentrations of Iron?

Where would somebody find the highest concentrations of Iron on or near Earth's surface?
7 votes
2 answers
583 views

What fraction of Earth's crustal material survives the supercontinent cycle?

I know that things are not as simple, but for the sake of argument I'll assume a supercontinent cycle of $\sim$400 Myr periodicity is active on Earth. If that is the case, then my naive ...
5 votes
1 answer
491 views

Why does the loss of water from a felsic magma encourage crystallisation?

Felsic magmas crystallise in the crust, unlike mafic magmas which tend to make it to the Earth's surface, for the following reasons: They are more viscous than mafic magmas and therefore it is ...