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30
votes
3answers
7k views

Why do felsic materials have lower melting points than mafic?

It is clear from Bowen's reaction series that more felsic minerals have lower melting points than mafic minerals. As far as I know, the same is true of quenched glasses. Felsics have a higher degree ...
13
votes
1answer
1k views

Why does the “Ring of Fire” pretty much define “Pacific Rim”

The Pacific Rim is pretty much defined by the so-called "Ring of Fire." It consists of the "stomping ground" for a disproportionate number of earthquakes and volcanoes, and the affected territory ...
11
votes
1answer
414 views

Is the Yellowstone National Park unique for its geysers?

The Yellowstone National Park in Wyoming is unique for its large number of "thermal occurrences, of which there are some 30 geysers. This, in turn, appears to be the result of the presence of large ...
21
votes
7answers
2k views

What tools allow a quick comparison of NetCDF output from ocean models?

I am writing my own MATLAB scripts to do most of the visualization and data analysis of model results. I wonder if there is a quicker way for visual comparison of simulation results gained from ...
9
votes
1answer
416 views

How can I create a CF compliant netCDF file?

I have been looking for a proper way to create a netCDF file that is compliant with the Climate and Forecast (CF) Metadata Convention. It is amazing that I can find a compliance checker for NetCDF ...
15
votes
2answers
403 views

What, if any, paleoclimate data can be derived from stromatolite fossils?

Stromatolite fossils have a layered structure vaguely reminiscent of tree rings, which are a well-known source for climate data. Although the formation process of stromatolite layers is less seasonal ...
24
votes
1answer
633 views

Why did the Laki eruption of 1783 produce so much fluorine?

The Laki fissure eruption of 1783/4 in Iceland was not particularly large or explosive, but it is infamous for the large quantities of fluorine (or hydrofluoric acid) and SO2 that it produced, and the ...
12
votes
2answers
250 views

What are the ramifications to life on Earth when the Earth's magnetic poles switch?

This question is related to this question about the cause of the Earth's magnetic field switching polarity. My question is: How does this switch in the polarity of the magnetic field affect life on ...
14
votes
3answers
1k views

Why is there a line of volcanoes along the northwest coast of North America?

Mount Hood in Oregon is a dormant volcano, and in Washington Mount St. Helens and Mt. Ranier are both active volcanoes. What causes this line of volcanoes running parallel to the coastline along the ...
16
votes
2answers
747 views

How does remote sensing of ocean currents work?

I am aware that techniques exist for measuring surface currents using HF radar, either from land-based installations or from space. How do these work? I have assumed in the past that it's some sort ...
15
votes
3answers
206 views

What supports the Rockies?

What supports the Rocky Mountains in North America? Or put another way, Why are they there? and Why are they still there? It might be tempting to think of compression, especially in an east-west ...
9
votes
0answers
100 views

Any other fumarolic ice caves in the literature? [closed]

I study the fumarolic ice caves of Erebus Volcano, and am looking for published research on similar sorts of caves. My criteria for a "fumarolic ice cave" are that it must be: A gas-filled void space ...
11
votes
1answer
836 views

What causes “hydrocarbons” to take the form of petroleum versus natural gas?

"Hydrocarbons" are found in geological formations consisting of strata or layers of rocks. Specifically, they are formed from decomposed organic material (that contains carbon), that bonds with ...
10
votes
1answer
689 views

How deep was the Vredefort Crater when it happened?

The Vredefort Crater is one of the biggest known impact craters on earth. How deep would it have been, relative to the original ground height, immediately after the dust settled, and before any ...
16
votes
2answers
1k views

What temperature do small meteorites have on impact

A question which has haunted me for years. What temperature do small meteorites (which don't evaporate on impact) have if you find them immediately after they hit the surface. I understand that the ...
19
votes
1answer
295 views

Why Earth's magnetic poles are (and were) in their positions?

This is a sort of a follow-up question to What causes the Earth to have magnetic poles? The Earth has magnetic fields, and according to dynamo theory I roughly understand why. If the Earth's rotation ...
13
votes
1answer
354 views

Which are the biggest methodological differences between the archaeological and geological approaches to stratigraphy?

Stratigraphy, or study of rock or soil layers (strata), was originally introduced as a branch of geology. However, it is often applied in other disciplines, especially in archaeology and paleonthology....
12
votes
1answer
508 views

Magnetic “magnetic hills”?

I have found on Wikipedia that the term "magnetic hill" is used for an optical illusion. However, I have heard that there are true magnetic hills, i.e., locations where you can't use compass simply ...
19
votes
1answer
608 views

What is the origin of the Montmartre mountain in Paris?

I have always wondered what is the origin of Montmartre mountain in Paris. What surprises me is that the whole area seems quite flat, and yet there's a very steep hill in the middle. How has that ...
15
votes
1answer
2k views

Why do Tsunamis travel slower than sound?

Tsunamis, in the deep ocean, travel at around 800 kilometers per hour. The speed of sound under water is about 5300 kilometers per hour. Both of these waves are pressure waves, operating in the ...
13
votes
3answers
9k views

Why is earth not a sphere?

We've all learned at school that the earth was a sphere. Actually, it is more nearly a slightly flattened sphere - an oblate ellipsoid of revolution, also called an oblate spheroid. This is an ellipse ...
13
votes
2answers
426 views

What causes the beautiful Auroras on the north and south magnetic poles?

What is the scientific reason for the majestic sights of the northern and southern lights, otherwise known as Auroras near the magnetic poles, and why do the northern lights differ from the southern ...
12
votes
1answer
699 views

Is there a standard definition of the term “mountain”?

Is there any standard internationally recognizable definition of the term "mountain"? If international texts describe some terrain as mountains, do they use some international definition of the term,...
18
votes
4answers
496 views

Is there any simple way of using the Coriolis effect to determine what hemisphere you are in?

I have heard from many people that sinks do not empty in a particular pattern depending on what hemisphere you are in, but I have also heard from people who adamant that a sink of water would empty ...
16
votes
2answers
2k views

How much Uranium is there in the Earth's Crust?

Are there any estimates of the amount of Uranium there is in Earth's Crust? From what I know, it's supposed that there are large amounts of Uranium in Earth's Core, the decay of which is responsible ...
14
votes
2answers
324 views

How does geothermal heating work?

I have heard that geothermal heating is a way of generating energy from the temperature difference between the inner layers of the Earth and the Earth's crust. How is it possible to extract this ...
15
votes
2answers
989 views

What causes the Earth to have magnetic poles?

A compass can tell me the directions of the Earth's North and South poles? What is it about the Earth that produces this "polarity" such that a compass can pick it up? The first thing that jumped ...
32
votes
5answers
5k views

How and why did the oceans form on Earth but not on other planets?

Earth is the only planet in our solar system that has copious amounts of water on it. Where did this water come from and why is there so much water on Earth compared to every other planet in the ...
16
votes
2answers
6k views

Why is the inside of the Earth so hot?

I have heard that the Earth is made up of four layers, being the crust, the mantle, the outer core and the inner core. I have also heard that the Earth's temperature increases as you move from the ...
0
votes
3answers
500 views

What are some good resources to learn about geophysics? [closed]

What are some good textbooks and online resources for learning about geophysics? That is, physics, as it relates to the earth's geology, shape, and internal structure.
35
votes
5answers
12k views

How is the mass of the Earth determined?

According to textbook knowledge, the mass of the Earth is about $6 × 10^{24}\,\mathrm{kg}$. How is this number determined when one cannot just weight the Earth using regular scales?
15
votes
1answer
88k views

Does a green or yellow sky actually indicate a tornado?

It seems to be a fairly widely held belief that if the sky is green or yellow, a tornado may be developing/approaching. But is there any truth to it? Could the color of the sky actually be associated ...
21
votes
3answers
388 views

Is fracking likely to produce earthquakes?

Post Christchurch-2011 earthquake, there was much concern that fracking in the surrounding areas might lead to further quakes, as was rumoured to have happened elsewhere in the world. Is there ...
11
votes
1answer
426 views

What periods of the fossil record are most lacking in specimens?

What parts of the fossil record are most lacking in specimens? That is, if you were to trace the evolution of a modern mammal (humans, for example) from abiogenesis to now, which periods are the most ...
18
votes
1answer
3k views

How long does it take for the ocean conveyor to circulate?

What is the period of the thermohaline circulation in the ocean? Obviously, individual particles may take longer or shorter, but what is the average for a small water parcel to do a full loop and end ...
25
votes
4answers
2k views

Can mining trigger earthquakes?

Are earthquakes more common in mining regions than they would otherwise be? e.g. is the frequency of earthquakes in those regions different when mining is occurring than when it is not? I am ...
31
votes
2answers
1k views

How much of the current global warming is due to human influence?

Approximately what proportion of the global warming seen over the the last century is attributed to anthropogenic sources?
8
votes
3answers
1k views

How deep could the surface of the Earth's crust get?

In theory, how deep can a natural formation on the surface of the Earth's crust be? What are the limits to this depth?
24
votes
3answers
7k views

What do weather forecasters mean when they say “50% chance of rain”?

What do weather forecasters mean when they say "50% chance of rain"? Even more confusing: weather report often says something like "30% chance of rain. >10mm", then the next day "70% chance of rain &...
14
votes
2answers
1k views

Why don't cold fronts and other steep-gradient weather effects just dissipate?

Why don't cold fronts and other steep-gradient weather effects just dissipate? Why do they last so long? Why doesn't the heat dissipate toward the cooler region?
11
votes
1answer
257 views

Are sandstorms like regular storms?

What's the difference between sandstorms and regular storms? Are they more than just strong wind within deserts?
12
votes
1answer
179 views

Why does every tsunami travel differently?

Tsunamis are quite interesting, as they only happen after a large displacement of water. Usually, the waves travel quite weirdly. Sometimes there are waves which bounce off of land and go back to sea....
19
votes
3answers
685 views

How do we know that we are NOT in an “Ice Age?”

Historically, the earth has had five "Ice Ages" Each of them lasted millions, tens of millions, or hundreds of millions of years. The last ice age reportedly ended perhaps 10,000 years ago. That ...
29
votes
1answer
2k views

What is the status of the Raymo & Ruddiman idea that Tibet cooled the Earth?

What is the current status of the Raymo & Ruddiman hypothesis that the uplift of the Tibetan Plateau during the Cenozoic cooled the Earth, resulting the current ice age(*)? cf. Raymo, M.E. and W....
19
votes
2answers
779 views

How does one measure what causes earthquakes?

I know that they occur when energy that was previously stored is released in seismic waves. But how is the energy stored in the earth in the first place, and what can trigger the release of such ...
11
votes
2answers
576 views

How do we measure (or empirically calculate) the amount of entropy in the atmosphere and oceans?

Here's a paper on the entropy budget1, where moist entropy is defined in equation (8) as $$ s = (1-q_t)(C_{pd} \ln T - R_d \ln p_d) + q_t C_l \ln T + \frac{q_v L_v}{T} - q_v R_v \ln \mathcal{H} $$ ...
14
votes
1answer
348 views

What are the impacts of sublimation on an annual mountain snowpack?

Massive amounts of freshwater rests atop the world's mountains in the form of ice, snow, permafrost, and glaciers. Many areas of the world rely upon the melting of snow and ice to recharge their ...
13
votes
0answers
649 views

How will climate change affect the entropy budget of the atmosphere?

The entropy per unit mass of moist air can be defined as $$s=(1-q_t)(C_{pd} \ln{T}-R_d\ln{p_d})+q_tC_l\ln{T} + \frac{q_vL_v}{T}-q_vR_v\ln{\mathcal{H}}$$ And in statistical equilibrium, the entropy ...
35
votes
2answers
859 views

Similarities between grand circulation solvers and mantle convection solvers

My impression is that both ocean grand circulation models (e.g. MITgcm), and Mantle Convection models (e.g. CitcomS), both use Navier-Stoke's as the governing equation. What are the other major ...
5
votes
1answer
59 views

Do river fluxes help contribute to long-term carbon sequestration?

Rivers help transport sediment from higher regions into the oceans (where it's hard to get back into the atmosphere). And this sediment could be carbon-rich.

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