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9 votes
Accepted

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
7 votes

Why is felsic (granitic) lava so much more viscous when flowing (or trying to) than mafic (basaltic) lava?

Several sites said composition, not temperature, explains most of the difference... They are correct. All other factors remaining equal, felsic magmas are more viscous. This is the result of higher ...
Gimelist's user avatar
  • 23.1k
6 votes

What would be the precursors to a repeated Lake Toba super eruption?

Massive, caldera-forming eruptions like the one at Toba usually happen at large silicic systems. At such systems, we expect a surface uplift as the pressure builds in the magma reservoir. This can be ...
Jean-Marie Prival's user avatar
6 votes
Accepted

How long does a stratovolcano live?

I was going to write an answer based on a few known examples (see my previous comment), but a few examples are not necessarily statistically representative. So I checked good old Encyclopedia of ...
Jean-Marie Prival's user avatar
5 votes

Why aren't there ultra acid igneous rocks?

As mentioned in a comment to another answer, the terms "basic" and "acid" in relation to igneous rocks are outdated and stem from an incomplete understanding of rock chemistry in ...
Gimelist's user avatar
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5 votes

Why aren't there ultra acid igneous rocks?

Warning: not an igneous petrologist here, I'm more interested in what happens to magmas once they reach the surface than all the processes they might have encountered along the way... That being said, ...
Jean-Marie Prival's user avatar
5 votes

Coral Reef and Volcanic Islands

I just came upon this paper by Tomascik et al. (1996). It does not answer directly your question, but I found it sufficiently relevant to post it here anyway. It is a study of coral colonization after ...
Jean-Marie Prival's user avatar
5 votes
Accepted

How far can an andesitic lava flow, and what is the velocity?

During my PhD, I listed many dacite and rhyolite flows, but also included a few andesite flows for comparison. Here are a few interesting examples, first of andesite flows that have been observed ...
Jean-Marie Prival's user avatar
5 votes

How far can an andesitic lava flow, and what is the velocity?

Andesitic lava is viscous, compared to basaltic lava. Andesitic lava flows at a rate of a few kilometers per hour, whereas basaltic lava can flow up to 10 km/h. Because of their viscosity, andesitic ...
Fred's user avatar
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5 votes
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What is meant by intraplate volcanism?

The majority of Earth's volcanoes occur in plate boundaries. These can be at spreading ridges (green dots on the map) where they are mostly underwater, but sometimes are above the water (such as in ...
Gimelist's user avatar
  • 23.1k
5 votes

What is meant by intraplate volcanism?

Terms: Intraplate volcanism - as the name suggests it is volcanism within the plates rather than at plate boundaries. These are also known as hotspots. Ocean island basalt (OIB) - is the basaltic ...
shul's user avatar
  • 133
5 votes
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Causal relationship between the simultaneous eruptions of Mauna Loa and Kīlauea? Does one cause the other or perhaps a third phenomenon cause both?

An article on this topic has recently been published: Elastic interaction between Mauna Loa and Kīlauea evidenced by independent component analysis (Przeor et al., 2022). It begins: The interaction ...
Jean-Marie Prival's user avatar
4 votes
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How does 10mm/yr of plate subduction provide enough material to create eruptions?

Yes, the situation is much more complex than you make out - the generation of melt is typically caused by partial melting of the mantle wedge located beneath the volcanic arc. This process is mainly ...
Conquistador's user avatar
3 votes
Accepted

Coral Reef and Volcanic Islands

based on Hunga Tonga, either within a decade or even before the volcano ever reaches the surface. https://link.springer.com/article/10.1007/s00338-019-01868-8 https://matangitonga.to/2019/12/09/...
John's user avatar
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3 votes

How much did the worst volcanic eruption in human history affect global temperature?

The largest volcanic eruption in human history was the Toba eruption on Sumatra about 75,000 years ago. There is still a huge lake, Lake Toba, in the crater. It dwarfed Thera, Krakatoa and Tambora. ...
Michael Walsby's user avatar
3 votes
Accepted

Subrelluric forces in a volcanic eruption

I believe what you heard is “subtelluric” where telluric means “of the earth”.
personjerry's user avatar
3 votes

Subrelluric forces in a volcanic eruption

This term does not exist in volcanology. I can’t even think of a similar sounding term that can be misheard in the song, or misheard by the authors and then put in the song. It’s possible it exists ...
Gimelist's user avatar
  • 23.1k
3 votes

Can a cryovolcanic eruption be as powerful as a normal volcanic eruption?

Here is a recent preprint about a possible super cryovolcano on Pluto. In this study, Cruikshank et al. analyzed the morphology and composition of Kiladze, a wide (~44 km in diameter) depression at ...
Jean-Marie Prival's user avatar
3 votes

How do you determine if basalt originates from a mid-oceanic ridge or from a continental flow?

The basalt from ocean floors is called a MORB (mid-ocean ridge basalt) while the basalt emplaced in a continental setting is usually an alkali basalt. They can be easily distinguished by their ...
Jean-Marie Prival's user avatar
3 votes

How come the pressure/shock waves of an explosive volcanic eruption almost always fail to cause any damage?

Volcanoes are not bombs, they don't explode through a high explosive reactions, it more about dissolved gases being released from pressure. More like shaking up a coke can and popping it, spraying ...
John's user avatar
  • 6,931
2 votes

What is meant by intraplate volcanism?

Intra = within/on the inside, so intraplate volcanism would be volcanism happening far from plate boundaries, usually hotspots. If you have trouble remembering intra- vs inter- remember international ...
John's user avatar
  • 6,931
2 votes
Accepted

Is there a 'standard size' for volcanic eruptions in terms of gas output?

There is no "standard volcano" or "standard volcanic eruption". However, to perform the calculation you want to do, you could use the "typical" of "average" volcanic eruption. The characteristics of ...
Camilo Rada's user avatar
  • 17.7k
2 votes
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Would a Yellowstone eruption destroy global agriculture?

An eruption of the Yellowstone super volcano would cause agricultural disaster over a very large area. Its global effect would be significant, but not totally devastating. The resulting climate ...
Fred's user avatar
  • 24.7k
2 votes

What causes lava eruptions (and shutoffs)?

Basaltic magma (pictured above) rises for several basic reasons: 1) High temperature, low density liquid mass that is buoyant relative to surrounding rock and 2) Low crustal overburden stresses that ...
Knob Scratcher's user avatar
2 votes

How does 10mm/yr of plate subduction provide enough material to create eruptions?

10mm a year is a huge volume when you multiply with lithosphere thickness and length of the boundary, but you are right - it's more complex than this. Melting is caused by the interplay of ...
user2821's user avatar
  • 5,946
2 votes

What is the largest earthquake attributable solely to volcanic activity

Earthquakes associated with volcanism or volcanic rifting are typically small. They are caused by over-pressurized magma as it moves around and intrudes into brittle rocks. Sometimes, e.g., in Hawaii,...
stali's user avatar
  • 2,381
2 votes

Why is felsic (granitic) lava so much more viscous when flowing (or trying to) than mafic (basaltic) lava?

Partial crystallisation products are the primary factor, iron and magnesium are many times more common in mafic melts than felsic ones. The minerals that are highest in iron and magnesium are the ...
Ash's user avatar
  • 4,290
2 votes
Accepted

How much did the worst volcanic eruption in human history affect global temperature?

I'm not well studied in this field, but I suspect that global average temperature by proxy for a single year is difficult to measure accurately. The 1991 cooling from Mt. Pinatubo happened recently ...
userLTK's user avatar
  • 5,857

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