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Questions tagged [volcanology]

The properties and behaviour of volcanoes.

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4
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2answers
184 views

Does the size of Earth increase due to volcanism?

In a volcanic eruption, magma rushes to the 'outside' of the Earth. Does this mean the size of Earth also increases? If not, how is the volume left after the magma rushed out refilled?
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Lava and Magma, Meteor and Meteorite--What's the Difference?

Some features of Earth (and beyond) have been bugging me for quite some time. When molten rock is beneath the surface, it's called "magma". Above the surface, it is called "lava". When a bolide is ...
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1answer
183 views

If I can drill a hole to mantle, does it form a volcano?

Suppose if I can drill a hole to mantle at arbitrary point of crust, will magma start rise from the hole and finally become a volcano?
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What is it about ancient craton geology that results in associated kimberlite pipes containing economic diamond deposits?

According to the Australian Geological Survey Organisation paper Kimberlite and lamproite diamond pipes (Jaques, 1998), economic deposits of volcanically-formed diamonds are restricted to ancient ...
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How big a risk is Mount Vesuvius for the local population?

How much of a risk does Mount Vesuvius pose for the population of the surrounding area?
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345 views

Do lava lakes exist in all volcanoes initially?

I know persistent lava lakes are rare, but do they occur in all volcanoes originally, and just not persist over time?
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528 views

Can we see lava in a divergent tectonic boundary?

Can we actually see an orange line of lava if we look down to the crack of the divergent boundary of tectonic plates?
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1k views

What is the source of lava of volcano? From magma below crust? Or from molten crust by rubbing?

Ok, it looks like a very simple question but I still have some point want to clarify... Most images explain volcanos contain some orange stuffs as magma below volcanoes as magma chamber, but the ...
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3answers
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Where can obsidian be found?

Where is obsidian found? Is it typically found on the surface or underground? If underground, how far under (meters or feet would be perfect)? Also, is it found everywhere on Earth, or just in areas ...
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1answer
120 views

Do discordants dykes ever travel concordantly (are transgressive dykes a thing)?

Transgressive sills "jump" between bedding planes, following joints: ...
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1answer
76 views

Earthquake severity during supereruption at Yellowstone caldera?

Theoretically, I ponder what type and strength a supereruption would generate, say for example at the Yellowstone caldera? The last supereruption was roughly 70,000 years ago when Toba erupted. It's ...
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1answer
198 views

Volcano magma chamber [duplicate]

If I use a really big drill and drill all the way down to a magma chamber what exactly would happen? From what I understand we cant drill to a Magma Chamber because it is really hot, but I have a ...
3
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1answer
118 views

How long would it take for Mars to cool after asteroid impact? [closed]

As someone interested in terraforming, the main obstacle to colonizing Mars is the lack of a magnetosphere and Atmosphere. To create a magnetosphere of sufficient magnitude the Martian core must be ...
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1answer
613 views

Are volcanoes formed from earthquakes?

I know that some earthquakes are caused by volcanoes and that some earthquakes can trigger volcanic eruptions close to where the earthquake is. But what if a great earthquake(8.0 or above) occurs and ...
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1answer
559 views

Does flow banding only occur in silicic rocks?

I made a video about what I learnt in my A Level Geology course so far, about igneous rocks. One thing I mentioned was that flow banding is mostly only found in silicic rocks (and so mostly rhyolite) ...
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2answers
253 views

What are the tectonic implications of the Quaternary Igwisi Hills, Tanzania, kimberlite volcanics?

The Igwisi Hills Kimberlite volcanic features in Tanzania are described in the article Mapping the Igwisi Hills kimberlite volcanoes, Tanzania: understanding how deep-sourced mantle magmas behave at ...
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612 views

Volcanoes in the Great Barrier Reef

Was there ever at any point in time a volcano in the great barrier reef? I thought atolls develop from volcanic islands, and the coral grow around them.
4
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1answer
72 views

Do the rocks below an active sill go down, or those above go up, or both?

Having read a little about sill formations like the Palisades Sill (eastern USA) and Whin Sill (UK), I understand that strata became separated by the injected layer of magma, with monumental ...
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2answers
357 views

Are Pompeii and Herculaneum unique?

Has anyone ever found or gone looking for similar locations, i.e. volcanic eruption sites in which unfortunate victims – human and non-human – have been entombed in the volcanic ash, with the ...
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1answer
111 views

Do higher global temperatures increase volcanic activity and earthquakes?

I've read that when global temperature increases significantly, liquid magma can make it's way closer to the surface of earth, causing increased volcanic activity and earthquakes. Is there scientific ...
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Is there any consensus of what caused the Lusi Mud Volcano eruptions in Indonesia?

In May, 2006, the Lusi Mud Volcano in eastern Java, Indonesia came to life, smothering much of the surrounding land in mud. According to the article Indonesia's Infamous Mud Volcano Could Outlive ...
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3answers
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What, if any, paleoclimate data can be derived from igneous rocks?

Paleoclimate data often derives from sedimentary rocks. Metamorphic rocks can also contribute to paleoclimate information in a wide variety of ways. What about igneous rocks? I guess that this can ...
5
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2answers
690 views

Red volcanic soils - what are the likely constituents?

I live very near an extinct Andesite volcano and hiking in that area I've noticed bands of soil that have a dark red coloration. I've also been in Kauai, one of the volcanic islands of Hawaii, but ...
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2answers
205 views

Can volcanos cause isostatic depression

Isostatic depression is normally associated with glaciation, but can other geologic processes result in similar behavior of the lithosphere? Especially, can the weight of a volcano cause the ...
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5answers
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Why does New Zealand and cold countries have volcanoes?

I understand that volcanoes are caused by the heat that causes high intense pressure below the Earth's surface. This intense pressure gets released and causes magna which becomes hot lava to flow out ...
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2answers
929 views

What precursor geological activity occurred prior to the Parícutin Volcano eruption in 1943?

Parícutin Volcano, sometimes referred to as the 'A Volcano Born in a Mexican Cornfield' (which is also the title of a book published in 1993, more information here), was one of the most well ...
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1answer
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What would the precursors to a repeated Lake Toba super eruption?

Lake Toba, Indonesia is a supervolcano which was the site of a massive supervolcanic eruption estimated at VEI 8 that occurred 69,000 to 77,000 years ago, representing a climate-changing event. It ...
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1answer
447 views

Why would volcano eruption cause cardiac arrest?

Following recent eruption of Mt Ontake and the sad news of over 30 people found in 'cardiac arrest', why would the eruption cause it? My initial thought would be that the cause of death would ...
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1answer
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Is this article self-contradictory, or am I missing something?

This article: Anderson, C. H., C. J. Behrens, G. A. Floyd, and M. R. Vining. 1998. “Crater Firn Caves of Mount St. Helens, Washington.” Journal of Cave and Karst Studies 60: 44–50. discusses, among ...
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1answer
263 views

What percent of volcanoes are glaciated?

I have not been able to find an estimate of how many known volcanoes host perennial ice masses, and it would be very useful to me. Does anyone know of any attempts to do this?
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2answers
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What is the geothermal potential of a volcano?

If there were lots of geothermal plants—even mobile ones—near a volcano, how much power could this provide? Could the sapping of some of the heat energy make the volcano less likely to erupt?
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1answer
781 views

What is the most powerful natural catastrophic event on record?

Natural catastrophic events such as hurricanes, earthquakes, volcanic eruptions and meteor impacts releases vast amount of energy. What is the most powerful single event of such nature ever recorded ...
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1answer
770 views

Are coral cays and coral atolls just volcanic islands?

Are coral cays and coral atolls just a different type of volcanic island? When I hear: "volcanic island" I think at places like Moorea or Hawaii, but ultimately, coral cays and coral atolls lay their ...
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2answers
380 views

What are some of the strongest theories against the existence of mantle plumes?

Among the people I interact with in the geodynamics community, it seems that almost all of us are in full support of the mantle plume theory. What are the strongest arguments against this theory? Is ...
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1answer
240 views

How do mantle plumes travel from the core of Earth to the crust?

As mantle plumes begin in the core and move towards the crust, I would have thought that the heat in the mantle plume would disperse to the surrounding mantle, and the plume would cease to exist by ...
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1answer
280 views

What is the geochemical origin of carbon dioxide with the 'white smokers' of the Champagne Vent?

Associated with the NW Eifuku volcano, a small submarine volcano in Japan's Volcano Island chain in the Pacific Ocean is a carbon dioxide rich hydrothermal vents called white smokers by NOAA (see ...
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1answer
578 views

What are the tallest hydrothermal vents in the world?

Hydrothermal vents are commonly found near active volcanic areas and provide for a rich and complex environment for many biological organisms (archaea, bacteria, tube worms...). Many new hydrothermal ...
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1answer
1k views

Why do Volcanoes give out so much Sulphur Dioxide and Carbon Dioxide?

From my understanding, the mantle is in a highly reduced state, so I can't understand why a volcano would give off a highly oxidised gas such as sulphur dioxide. Carbon dioxide is too an oxidised ...
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1answer
1k views

Was volcanic activity more prevalent when the dinosaurs roamed?

Popular film culture often depicts much volcanic activity during the time of the dinosaurs. Assuming "time of the dinosaurs" as the Jurassic (200 million years ago) until the end of the Cretaceous (...
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3answers
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Why does Volcano Lightning occur?

There are many pictures I've seen of lightning coming out of the plume of smoke caused by a volcano (Often called 'Volcano Lightning'). Example: Why does this happen?
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1answer
336 views

What ozone depleting chemicals can salt produce?

According to How Long Will Life Last On Earth, 250 million years ago Siberia underwent a large a prolonged period of volcanic activity. It has been speculated that large salt deposits that existed in ...
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1answer
295 views

What causes the entrainment of atmospheric gases towards a volcanic ash/tephra plume?

I understand that volcanic ash plumes can only rise to great heights (e.g. 50km) with the help of some other processes, as the velocity of the material ejected isn't great enough to send it high into ...
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1answer
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What caused a measurable patch of Mt. St. Helens' ash to be deposited across Oklahoma?

Looking at the ashfall distribution map from the 1980 eruption of Mt. St. Helens (below), there is a measured 'patch' of ash depth significant enough to be measured occurring in Oklahoma. What caused ...
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3answers
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Why don't scientists use fire entry suits to study volcanoes?

It seems like the only personal protective equipment (PPE) that volcanologists use are aluminized suits that don't provide any protection from direct contact with lava, making an unexpected splash ...
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1answer
125 views

Do different lavas have different volcanic volatiles associated with them?

This question was inspired by the question Predicting volcanic eruptions by experimentally proven volatile outgassing observations Depending on the type of volcano, three types of lava are released ...