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51 votes
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Why is Olympus Mons the largest volcano in the whole solar system?

This is mostly due to the fact that Mars does not have plate tectonics. Therefore the plate stays above the hotspot without moving, allowing magma to rise and pile up at the same place for millions ...
Jean-Marie Prival's user avatar
21 votes

Do volcanos really create fertile soil?

As always: It Depends. Assuming enough water and sunshine, crop growth rate boils down to the concept of limiting nutrients. These may be: nitrogen (via ammonia or nitrates), phosphorous (via ...
Andrew Jon Dodds's user avatar
21 votes

If the Bennu asteroid were to hit within a 500 mile radius of Yellowstone National Park, will it trigger a super volcano at Yellowstone?

There is actually an hypothesis that large asteroid impacts can trigger volcanism at the antipodal point, where the seismic energy of the impact focuses. On Earth, it has been suggested that the ...
Jean-Marie Prival's user avatar
20 votes

Why is basalt denser than granite?

Magmas have a wide range of chemical (and mineralogical) compositions. Basalts come from mafic magmas (they used to be called "basic" magmas), while granites come from felsic magmas (used to ...
Jean-Marie Prival's user avatar
17 votes
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If the Bennu asteroid were to hit within a 500 mile radius of Yellowstone National Park, will it trigger a super volcano at Yellowstone?

Maybe but it will depend on the state of the magma chamber under the caldera. If the magma chamber is already under enough pressure and has a super-eruptive quantity of liquid melt in it then the ...
Ash's user avatar
  • 4,550
16 votes
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How did CO₂ originate on Earth before there was life?

The answer is Volcanos. There might be other inorganic processes capable to produce $\text{CO}_2$, but on Earth, the main inorganic source of $\text{CO}_2$ are volcanoes. In some period of Earth's ...
Camilo Rada's user avatar
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14 votes
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Why do human populations concentrate near fault lines, volcanoes, etc.?

You're asking Why do human populations concentrate near fault lines, volcanoes, etc.? But the real question is Do human populations concentrate near fault lines, volcanoes, etc.? And the ...
Gimelist's user avatar
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14 votes
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Why are the latest additions to the Hawaiian-Emperor seamount chain the highest?

As it was explained to me at university there are two factors; buoyancy and erosion. Rock buoyancy is a major factor, fresh Basalt is hot and dry and has a much lower density than older oceanic ...
Ash's user avatar
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14 votes
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If people aim to reach the mantle, why don't they just use volcano craters?

why don't they just use volcano craters? Because volcano craters don't go to the mantle. Here's a sketch of how the crust, mantle, and volcanoes look like: Tan colour is crust, orange is mantle. ...
Gimelist's user avatar
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13 votes

Why do some earthquakes and volcanoes occur within plates?

Crustal plates are not homogeneous, uniformly continuous rock masses with uniform stresses. They are a mixture of rock types with variable stresses and stress concentrations. They are also ...
Fred's user avatar
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13 votes

What gases are in the vesicles of pumice?

Pumice does not contain any gas, the vesicles are empty1. The magma which generated the pumice used to contain gas, mostly water and CO2 like you said. But this gas was lost during the eruption. Most ...
Jean-Marie Prival's user avatar
13 votes

Why are there no volcanoes where continents collide with each other?

Or is the continental crust too dry? Exactly this. Continental collision zones are actually full of volcanic rocks, which formed at the time before it was a continental collision zone. The Wikipedia ...
Gimelist's user avatar
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13 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 ...
Fred's user avatar
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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). ...
Jean-Marie Prival's user avatar
11 votes
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What conditions could produce 50 km long lava tubes?

In Hawaii, the Mauna Loa lava tube from the 1859 lava flow enters the ocean about 50 kilometers (31 mi) from its eruption point And in the Undara Volcanic National Park in Queensland, Australia ...
Fred's user avatar
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11 votes
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Is this a former volcano in the Hamad Plateau, in the Syrian desert?

My Rand-McNally Atlas shows the signature for lava fields in that area. The elevations in Google Maps indicate concentric contour lines with only small differences in elevation, rising from 600m at ...
njuffa's user avatar
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11 votes
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Which percentage of $\text{CO}_2$ emissions are human made emissions?

First of all, the amount of carbon cycling trough the Earth's system is irrelevant to the discussion of the changes in atmospheric $\text{CO}_2$ concentration or ocean acidification. In the same way ...
Camilo Rada's user avatar
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10 votes
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Can human activity affect volcanoes?

I think you have drawn the 'short straw'! As disasters go, volcanoes have about the least to do with human activity. Basically, volcanoes are the product of plate tectonics, which operates on a scale ...
Gordon Stanger's user avatar
10 votes
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Is the momentum of a volcano's high-velocity ejecta mostly due to expanding gas?

The ejecta and their momentum appear to be entirely the product of the dissolved gasses in magma, according to this page on Physicochemical Controls on Eruption Style on the How Volcanoes Work pages ...
jeffronicus's user avatar
  • 3,487
10 votes
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Volcano in ocean?

From a list & map of known seamounts and submarine volcanoes it is unlikely the orange region in your picture is a submarine volcano. The average depth of the Pacific Ocean is 4280 m. At such a ...
Fred's user avatar
  • 24.7k
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 ...
Gimelist's user avatar
  • 23.2k
9 votes
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Why did it take so long to discover the volcanic nature of mid-oceanic ridges?

If it weren't for WW2 and the search for German submarines, the discovery of mid-ocean ridges might have waited until satellite based gravimetric mapping in the 1980s. It was the use of fine ...
Knob Scratcher's user avatar
9 votes
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Is the iron on Earth's crust a leftover of the Iron catastrophe, or it was brought back by volcanoes?

Not all the iron sank to the core. Have a look at my answer to a previous question: https://earthscience.stackexchange.com/a/7076/725 Your question is similar, but coming the other way. You're ...
Gimelist's user avatar
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9 votes

Why is Olympus Mons the largest volcano in the whole solar system?

The other answer is already pretty good: No plate tectonics and no water erosion allows material to pile up in one place, and then stay put. Neither is the case on earth: The plate moves away from the ...
Wolfgang Bangerth's user avatar
9 votes
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Similarities and differences between lava flows and fluvial geomorphology (rivers)

The similarities pretty much end at the fact that both water and lava flow downhill seeking the lowest possible level. As even the most fluid lavas flow somewhat slower than water because of their ...
Ash's user avatar
  • 4,550
9 votes

If the Bennu asteroid were to hit within a 500 mile radius of Yellowstone National Park, will it trigger a super volcano at Yellowstone?

Bennu is about 470m diameter, and will impact at a "mere" 11.3km/s. At the impact site it would blast a crater some 3 miles wide and 1500 ft deep, a very respectable impact indeed. The ...
PcMan's user avatar
  • 191
9 votes
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Can people on the side of a volcano survive the eruption?

It's always hard to interpret the intentions of an author. But to me, "a rain of hot ash" does not sound like a pyroclastic flow, but rather like a tephra fall, which is a different volcanic ...
Jean-Marie Prival's user avatar
8 votes

Pyroclastic flow protection

The effectiveness of such shelters against pyroclastic flows have been wonderfully discussed by user889. However, I understand that those shelters were never intended to protect against pyroclastic ...
Camilo Rada's user avatar
  • 17.7k
8 votes

If I could drill a hole into the mantle, would it form a volcano?

As Bon says, the mantle is solid, albeit somewhat viscous / plastic under the prevailing pressure and temperature conditions, so your hypothetical borehole isn't going to puncture any liquid magma ...
Gordon Stanger's user avatar

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