33 votes
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How can we determine the size and composition of Earth's inner core?

We know the the size of the inner core through seismology. From my answer to this question: How are subsurface wave speeds determined without subsurface sensors?, we can determine the speeds of the ...
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  • 6,356
32 votes
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Could the Earth's core lose its heat?

Part 1, see Neos answer. Earth will lose its heat no matter what we do, and our extraction of geothermal energy is insignificant (Wikipedia quotes a BP figure of 11.4 GW electrical, 28 GW heating). ...
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20 votes

Could the Earth's core lose its heat?

This question is relevant, Why is the inside of the Earth so hot? The short answer is the core is losing heat no matter what we do. You see, heat is transported from the core to the surface, but its ...
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  • 6,356
20 votes
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What are some of the strongest theories against the existence of mantle plumes?

The best argument I've heard supporting strong skepticism of plumes, if not total dismissal, is that the theory is too flexible. To put it more bluntly, this amounts to saying that it is unfalsifiable ...
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  • 10.8k
18 votes

Are the processes of the rock cycle currently in dynamic equilibrium?

It's an interesting question, but in practice I think it's impossible to answer. It's very difficult to measure the rates of many of those processes, and the divisions between rock types can be quite ...
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  • 5,380
18 votes

Could the Earth's core lose its heat?

Put a frying pan on a stove burner and make the pan hot. Measure its temperature every minute over half an hour or so to get an idea of how rapidly it naturally cools. Then start the experiment over ...
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17 votes

Why is the temperature between the earth core and surface not distributed linearly?

The temperature does indeed increase with depth, something that is a problem in deep mines or deep drilling, but a benefit for geotermal heating. The heat originates mostly from radioactive decay, but ...
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  • 5,896
16 votes
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Does volcanic activity fluctuate?

This is probably an observational effect that is quite common in the Earth Sciences. In scientifically progressing societies there is a higher proportion of observations due to a number of effects: ...
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  • 3,876
16 votes
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What are the implications of the recent discovery that huge oceans exist close to the mantle of the Earth?

I am going to assume that you are referring to recent new stories with titles like "Rare Diamond Confirms That Earth's Mantle Holds an Ocean's Worth of Water" (Scientific America). These articles are ...
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  • 541
16 votes
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Why won't Yellowstone explode?

This is a complex question, and I cannot give you a complete answer I'd like to point out that there is a very important article published in February of this year on the subject: volcanoes are in an ...
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  • 6,356
14 votes
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How do I derive the formula for lithostatic (overburden) pressure?

This isn't that difficult, but anything is if you start from the wrong place. Let's derive this thing: $$P = \frac{F}{A}$$ Where $P$ is pressure, and $A$ is the area the force is pushing down on. ...
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  • 6,356
13 votes

Does volcanic activity fluctuate?

Whether volcanic activity fluctuates depends rather on the timescales you are looking at. Crisp (1984) compiles available data on igneous activity lasting for longer than 300 years and concludes that ...
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  • 2,826
13 votes

Could the Earth's core lose its heat?

Could all the drilling and digging to use the earth's natural heat as geothermal energy be affecting Earth's core, causing it to cool down? Yes. But by how much? Let's do some rough math. We'll just ...
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13 votes

Could the Earth's core lose its heat?

... causing it to cool down? This answer to the question 'Why has Earth's core not become solid?' over on Physics seems to claim the answer is no. The core is heated by radioactive decays of ...
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  • 239
13 votes
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What are the causes of the supercontinent cycle?

Please take into consideration that I am not a specialist of plate tectonics, just a paleontologist. Although this cycle is often nicknamed the Wilson cycle (probably because of Wilson, 1966), the ...
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  • 5,238
13 votes

Are the oceans rising or the continents going down? How can we know?

To the best of our knowledge, sea-level is rising because the volume of water is increasing. There is substantial local variation in sea-level change; it's falling in some parts of Canada. But of the ...
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  • 10.8k
12 votes
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Similarities between grand circulation solvers and mantle convection solvers

Disclaimer: This is a partial answer given that my background is modeling of the ocean. I hope that some mantle convection modelers can complement this answer. The question is good but the answer is ...
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12 votes
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Is the Yellowstone National Park unique for its geysers?

Yellowstone is thought to be above a mantle plume, of with there are tens to hundreds on our planet, although there is plenty of debate on this matter. The exact nature of mantle plumes is a huge area ...
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  • 2,563
12 votes
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Gaps in locations of volcanos (Peru & Chile)

As you said, the Andean belt is divided into four segments, usually called the northern, central, southern, and austral volcanic zones (NVZ, CVZ, SVZ and AVZ, respectively; your map lacks the AVZ). ...
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12 votes

How plausible is it that "a portion of the ocean's floor" could suddenly be "thrown up to the surface" as described in this Lovecraft story?

Generally the Earth's geology moves very slowly, ... very slowly. When people use the term geological time scales they mean a very long period of time, usually in the millions of years. In volcanic ...
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11 votes
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Why does Earth's outer-core rotate in the opposite direction to the inner-core?

Is it true that Earth's outercore rotates in the opposite direction to Earth's inner-core? No. You misread a badly written for-the-masses science article. The article summary is at best rather ...
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10 votes
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When a tectonic plate subducts, does any of the subducted material melt, or is it just the mantle above the subducted slab that melts?

This is a very good question Inkenbrandt. It is quite common for even some graduate students to think that the majority of partial-melting comes from the slab: when it is the the mantle above the fore-...
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  • 6,356
10 votes

Are old geophysics textbooks useful?

Mathematics and computer science are exact sciences. If something is discovered and known, it is not wrong. With time, there may be better or new ways of doing something, but the old stuff is still ...
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  • 22.2k
10 votes

How plausible is it that "a portion of the ocean's floor" could suddenly be "thrown up to the surface" as described in this Lovecraft story?

Very implausible. If your sailor is actually in the middle of the ocean, there are several kilometres of water underneath. Nothing that we know of can uplift kilometres of rock overnight, at least ...
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  • 22.2k
9 votes

How can we determine the size and composition of Earth's inner core?

Scientists used the seismic waves created by earthquakes bouncing off the core to map out the approximate size of the earth's inner core. The materials that constituted the core were guessed with the ...
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  • 2,802
9 votes
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How do mantle plumes travel from the core of Earth to the crust?

The high values obtained when estimating the Rayleigh number for the mantle indicates that convection there is vigorous, and that convection is responsible for almost all the heat transported from the ...
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  • 3,780
9 votes
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Simulating the earths crust

I am afraid that you aren't being specific enough to really answer your question: What about mountain chians valleys and hills are you interested in? There are simple and complex models dating back ...
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  • 6,356
8 votes

Why does Earth's outer-core rotate in the opposite direction to the inner-core?

The answer is that there are more forces than just the momentum of the earth at play. The electromagnetic force generated by the core is pushing on itself, in fact: "The fact that Earth's internal ...
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  • 6,356
8 votes

What is the reasoning behind the statement "Faulting will occur along the plane where the shear stress is the highest"?

This statement is referring to depths within the crust where the lithostatic pressure is sufficiently high to suppress the formation of dilatant fractures. Rock is a brittle material, and if loaded to ...
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  • 3,780
8 votes

What is the reasoning behind the statement "Faulting will occur along the plane where the shear stress is the highest"?

This statement is known as the Wallace-Bott hypothesis. It is mostly valid for reactivated faults rather than fresh rocks(where cohesion comes into play). It says that the slip in a fault plane will ...
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