Questions tagged [volcanology]

The properties and behaviour of volcanoes.

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48 views

What is this dull whitish rock with ornate black patterns found in the Arkansas Crater of Diamonds?

I found this rock while wet sifting dirt brought back from the Arkansas Crater of Diamonds. It looks as if it is hand painted. It is smaller than my pinky nail. It’s dull, and makes a chalk-like mark ...
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Pyroclastic flow protection

Related to the question Why don't scientists use fire entry suits to study volcanoes?, where the issue of volcanologist protection against lava splatter and bombs is discussed. Another major and ...
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844 views

Volcanoes in the Alps and Himalayas and the subduction of Tethys Sea

Geologist have theorized that the Tethys Sea subducted under Eurasian plates. But where are the volcanoes that would have resulted due to this? Where are the volcanoes in the Alps and the Himalayas?
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Is the iron on Earth's crust a leftover of the Iron catastrophe, or it was brought back by volcanoes?

When pondering the hypothesis of the Iron catastrophe, that seem to be widely accepted nowadays. It surprises me that currently the crust still contain a significant amount of Iron (5.6% in weight). ...
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What is likely to have happened with these newly discovered antarctic volcanos below the ice?

The Guardian article Scientists discover 91 volcanoes below Antarctic ice sheet highlights a recently published University of Edinburgh School of Geosciences discovery and cataloging of over ninety ...
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The formation of West Mata

I was wondering if anyone knows how the formation of the West Mata volcano came to be? I was reading that a lot of underwater volcanoes were formed by convergent boundary. Is this how West Mata was ...
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What are the high field strength and large ion lithophile (HFS or HFSE & LIL or LILE) elements?

There are two groups of elements that are frequently mentioned when discussing incompatible trace elements. They are the high field strength elements (HFS or HFSE) and the large ion lithophile ...
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Volcano in ocean?

Is it a volcano in this image ? The magnified version. I was browsing through earth images here when I spotted this orange thing. Is it some oceanic volcano? It may be an absurd question but is it ...
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How is tiltmeter data processed?

With what programs can inclinometer data be processed? And how is instrumental correction done?
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1answer
431 views

Would a Yellowstone eruption destroy global agriculture?

Someone recently claimed in my hearing that if the Yellowstone caldera were to erupt, the resulting ash cloud would end all agriculture for a year or two. (The speaker is not a scientist, and neither ...
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1answer
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A circle shape in Madagascar

I was seeing Madagascar on Google Maps and accidentally i saw a circle shape near Bebao. Coordinates are 17.4317443°E and 44.644248°S. Please, to satisfy my curiosity, can you tell me why is this ...
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Possibility of Domino Effect

Is there any likelihood that an earthquake could trigger a volcanic event? I'm thinking that because the Pacific tectonic plate nearly coincides with the "ring-of-fire," particularly along the west ...
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137 views

Can Volcanic Eruptions Help Combat Global Warming in the Long Run?

I've been reading about volcanic eruptions on wikipedia, and I've found that very big eruptions cause the earth's temperature to drop by a small fraction of a degrees Celsius due to the ash it ...
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What conditions could produce 50 km long lava tubes?

Detection of a new 50 km long lava tube in the Moon has just been reported. See JAXA probe finds 50-km cavern under surface of the moon, this JAXA news page (the English page has not yet been updated, ...
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What caused the high temperatures that resulted in the Cretaceous aged komatiite lavas of Gorgona Island, Colombia?

According to the San Diego State University (SDSU) webpage Unusual Lava Types, komatiite is ultramafic volcanic rocks, having very low silica contents (~40-45%) and very high $\ce{MgO}$ contents (~...
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Can volcanos change the climate?

I have heard politicians claiming that volcanoes are the sole cause of global warming and using so called "NASA data" to show that the Earth is actually cooling instead of warming. While the nature ...
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how high was mount vesuvius (mount somma?) before it erupted in AD 79?

I guess the highest point of the Mount Vesuvius / Mount Somma complex is currently 1,281 metres (4,203 feet). My question is: how tall was it before it erupted in AD 79?
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Why do human populations concentrate near fault lines, volcanoes, etc.?

I've noticed that many places with large populations tend to be prime zones for natural disaster. Examples: Silicon Valley = earthquakes, Houston = hurricanes and floods, Japan = tsunamis and ...
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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 ...
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Volcanoes and Lightning [duplicate]

Just wondering about this question has been popped into my head many times and as what I have seen in some volcanic activities that when a volcano erupts there's a lightning, & i don't know if ...
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2answers
356 views

Water and explosive volcanoes in the Pacific ring of fire

Most volcanoes in the Pacific Ring of Fire have an explosive nature. This is due to high concentrations of water in their magma. Obviously, this magma comes from several kilometres below the earth's ...
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Do volcanos really create fertile soil?

I'm developing an ecology for a portion of my world that's geologically active and I remembered hearing that volcanic ash in soil makes it more fertile to agriculture. After extensive googling I've ...
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Why doesn't the whole volcanic cone appear black?

Cooled lava looks black, but why the whole volcano, even near crater, doesn't always appear black like cooled lava?
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What happens to the earth after volcanism/tectonics slows?

If we move far enough into the future that the core begins to solidify to the point that volcanism and tectonics are non-existent, what does the surface of the planet begin to look like? Does the ...
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How are data from tiltmeters used to monitor volcanic activity?

I've just learned in this answer that tiltmeters (which I assume measure changes in tilt) are used near active volcanos. (Saw a mention in item 4. here also.) What kind of geological (volcanological?)...
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How are Mauna Loa $\ce{CO2}$ monthly trends computed?

The problem I am trying to figure out how $\ce{CO2}$ concentration trends are computed in the data provided by the Earth Systems Research Laboratory Mauna Loa Observatory. The data contains monthly ...
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The position of magma chambers

Where do magma chambers exist? Is it necessary that they exist in the asthenosphere where the circumstances of temperature and pressure are suitable for the rocks to be molten? Or they exist in places ...
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What drove the Puy de Dôme volcano?

The Puy de Dôme is an extinct volcano located pretty much smack in the middle of France. It last erupted some seven thousand years ago, which in geological terms is fairly recent - prehistoric humans ...
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What geological processes affect the speed of Kilauea lava flows?

The recent lava flows from the current eruption from the Kilauea volcano in Hawaii have generated a considerable amount of interest and concern for property. In the article slow-motion disaster as ...
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Why did it take so long to discover the volcanic nature of mid-oceanic ridges?

I just read this article and was astonished to see the following: Oceanographers stumbled on [the mid-oceanic ridges'] volcanic nature in 1973. What I find surprising is how recent that is. ...
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643 views

What would happen if magma flows into a very large oil deposit?

If there were an earthquake that somehow cause a crack in the earth and allowed a significant amount of magma to flow into a very large oil deposit. With that high amount of explosive energy that ...
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Is the momentum of a volcano's high-velocity ejecta mostly due to expanding gas?

When I was very young I was always amazed that water didn't come shooting up out of the first ice-fishing hole of the season, due to the weight of all the ice. It doesn't, because the weight of the ...
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What geological events could cause a Volcanic Explosivity Index (VEI) level 9 eruption?

The Volcanic Explosivity Index (VEI) is a way of measuring the relative explosiveness of volcanic eruptions, allowing for comparisons between volcanoes. According to the USGS Volcanic Hazards page, ...
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What processes produced the basalt columns of the Giant's Causeway?

The Giant's Causeway is, according to the Wikipedia page was formed during during the Paleogene Period, Antrim was subject to intense volcanic activity, when highly fluid molten basalt intruded ...
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What causes lava eruptions (and shutoffs)?

I understand the process of volcanism and the reason for magma deposition on the surface of the earth. What is not clear to me, or what seems to be less well explained is why eruptions occur and then ...
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1answer
163 views

Yellowstone Eruption Possibility?

What is the probability of the Yellowstone supervolcano erupting during any given year? I had heard that it erupts once every 100,000 years. Does that mean there is a .001% chance of it erupting ...
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Basalt vs. columnar basalt

I recently visited a cliff on the south coast of Ulva in the Inner Hebrides where there are ~10m thick flows of columnar basalt. The columnar basalt forming most of the cliff is sandwiched between ...
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Can impact events cause widespread volcanic activity on the other side of the planet?

The currently accepted theory for P-T mass extinction is environmental change triggered by the Siberian Traps volcanic activity. A paper(1) suggests that the Siberian Traps were caused by a hotspot ...
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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 ...
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What is solidus and liquidus temperature of granite?

My understanding is that because a rock is composed of variety of minerals, so it does not have fix melting point, rather there is a range below which whole rock is solid and above which whole rock is ...
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1answer
191 views

If lava flows back into the ground, would it be called magma?

If lava flows back into the ground, would it be called magma again? Is there a difference if it flowed into a new hole vs the flow it came from?
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Is the magma in one volcano different from the magma in every other volcano?

First off, a confession: I'm asking this question because of The Lord of the Rings. If you're not aware already, in the story, a magical ring can only be destroyed in a specific volcano. The reason ...
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Magma resultant from group 1 and group 2 elements?

I was recently speaking with a geology professor over lunch at a university who has a theory that I've never heard before. His postulation was quite compelling and I was hoping to do a little digging ...
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Difference between the oxygen/$CO_2$ ratio during the period of the dinosaurs and the present

Here's the base of my question: Was volcanic activity more prevalent when the dinosaurs roamed? Is it true that during the time of the dinosaurs, both the oxygen requirements (by all living creatures ...
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1answer
160 views

Are the other causes of an earthquake (e.g. volcanic eruptions) the cause of the “sudden slip” which is the main cause of an earthquake?

I am to deliver an informative speech about earthquakes in class. However, I was not the first to talk about earthquakes and his discussion of the cause of earthquakes is different from mine. He ...
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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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179 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?