Questions tagged [volcanology]
The properties and behaviour of volcanoes.
181
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2
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1answer
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“Obicular” structures in basalts
I found spherical or globular structures, structures in basalts of a greenstone belt which underwent alteration and deformation. However, in thin section, these structures have undeformed pyroxene and ...
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0answers
36 views
Coral Reef and Volcanic Islands
I have two questions regarding coral reef and volcanic islands.
When a new volcanic island is formed, how much time generaly passes before a coral reef starts to form around the island?
Another ...
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0answers
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What determines the scale of columnar jointing?
What physical parameters determine the scale of columnar jointing?
What makes the columns thinner or thicker?
What makes them taller or shorter?
What causes the variation in a given site?
What ...
1
vote
1answer
43 views
How far a andesitic lava can flow and what is the speed?
For an effusive volcanic activity how far a andesitic lava can flow?
What is the speed?
Eruption amout 0.2 cubic km amount with 25 degree slope.
1
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0answers
40 views
Interpreting an outcrop of a thick pure silica bed in a volcanic setting
How can a nearly pure silica bed with 250 m x 50 m x 1.5 m dimensions be interpreted in a volcanic/pyroclastic setting? Here is a photo of it.
3
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1answer
56 views
Can volcanic gases be emitted in any other way besides volcanic eruptions
What other sources of volcanic gas emissions can there be on earth?
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0answers
55 views
How Big Were the Siberian Traps ORIGINALLY?
252 million years ago, Siberia was subject to a mass series of flood basalt eruptions, creating a large igneous province called the Siberian Traps. Today, it measures 2.7 million square miles in area ...
2
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1answer
45 views
Why are pyroclastic flows ground-bound?
This bugged me for a while:
Pyroclastic flows are fast (up to 700 km/h (430 mph) according to Wikipedia) and typically roll down the slopes of a volcano. E.g. here https://www.youtube.com/watch?v=...
9
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1answer
103 views
The Tambora eruption caused the “Year without a summer”. How much would such an eruption today affect the output of solar pv on a global scale?
Are there any estimates for the reduction of global solar insolation at the Earth's surface that a Tambora scale eruption would bring?
If our electrical power generation became heavily reliant on ...
11
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1answer
215 views
Which percentage of $\text{CO}_2$ emissions are human made emissions?
I was watching a science/myth Youtube channel (science mixed with a lot of speculative/fantasy content) with 2M+ followers and the Youtuber said volcano made emissions were higher than human made ...
3
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1answer
138 views
What kind of lava tube feature is Cleopatra's Grave?
Cleopatra's Grave is a natural feature inside (warning: PDF) Catacombs Cave in Lava Beds National Monument near Modoc, California.
Source: LookBeforeYouLive
My apologies, as this image is somehow in ...
3
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0answers
67 views
Do sound waves from volcanic eruptions travel around the world?
Do sound waves from volcanic eruptions travel around the world? I recently read about the Krakatoa eruption and how sound waves from that eruption traveled around the globe 4 times and were detected ...
1
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1answer
44 views
Coal fires affecting seismic activity, and also volcanoes
Can coal fires cause earthquakes to happen, or possibly prevent or postpone earthquakes? Also can coal fires trigger(or prevent) volcanic eruptions by affecting flow of magma underground or by some ...
4
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1answer
90 views
What is lava called if it has 56% to 64% silica?
We've learnt in science at school that "Mafic" lava forms rocks with 45% to 55% silica, meanwhile "Felsic" lava forms rocks with >=65% silica. So what is lava called in between? Or is it impossible ...
2
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1answer
126 views
Why exactly is the feature on Io called a volcano, and the feature on Enceladus called a geyser?
News of the long-lived and not unusual cloud on Mars associated with 21 km tall Olympus Mons has people commenting. This tweet by planetary scientist Dr. Tanya Harrison says
I don't understand the ...
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1answer
666 views
What is this big Black Mass in Syria, as seen on google maps? [duplicate]
What is this big black dot on the satellite view of google maps, located in Syria at about 4:00 from Damascus?
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0answers
15 views
Does outgassing change the isotopic D/H ratio?
It is known that the D/H-ratio of Earth's water inventory is very similar to that of asteroids. This is usually interpreted in a way that Earth's water must have come from similar, asteroid-like ...
4
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2answers
60 views
Subrelluric forces in a volcanic eruption
I am listening to a song about volcanoes. It is called "Pyroclastic Annihilation" performed by a brutal deth/thrash metal band called "Demolition Hammer". It is from their album "Epidemic of Violence" ...
3
votes
1answer
77 views
Where are these volcanos as seen in this space tweet?
In his recent tweet from the International Space Station as it's current Mission 56 Commander, NASA astronaut Andrew J. Feustel says:
This is #Indonesia as viewed from the @Space_Station. With the ...
4
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1answer
401 views
Why do some earthquakes and volcanoes occur within plates?
I know that volcanoes and earthquakes occur on plate margins. But, do some of them also occur within plates?
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0answers
28 views
Agricultural self sufficiency after yellowstone eruption?
Given a 440 acre farm running roughly 200 acres of Crops and 40-50 head of cattle,in the secondary ash zone within the lake of the ozarks reigon of Missouri, how viable would survival be relying on ...
5
votes
1answer
338 views
Can cooled/hardened lava rock return to a molten state?
Can lava that has cooled to a hardened state be returned to a molten state by, say, a new river of molten lava flowing over it - like re-smelting iron? If you threw a lava rock into the mouth of a ...
11
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1answer
271 views
Is this a former volcano in the Hamad Plateau, in the Syrian desert?
On my random explorations of google maps, I came across this interesting terrain:
(link to map here)
Apparently, this is part of the so-called Hamad Plateau, in the Syrian desert. If so, the rock ...
1
vote
3answers
316 views
Volcanic eruption force
From my research, some volcanic eruptions can produce enough force to turn a 10-tonne rock into a projectile.
Could a supervolcano produce enough force to turn a 35,000 tonne rock into a projectile?
...
6
votes
1answer
73 views
What theories exist connecting volcano temperatures to eruption probabilities?
Wikipedia names thermal monitoring as one of the methods for predicting volcanic eruptions. I was able to find some papers (First, Second) on such thermometry and while they are challenging (I retired ...
9
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1answer
696 views
Why are the latest additions to the Hawaiian-Emperor seamount chain the highest?
The Hawaiian-Emperor seamount chain stretches from Russia to the Hawaiian islands. When I look at them on a map, it seems that the oldest seamounts by Russia are shorter and smaller than the newer ...
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vote
1answer
590 views
Are there lava flows inside a volcano?
(source: netdna-ssl.com)
In these popular diagrams for the three types of volcanoes, it seems as though the lava flows are inside the mountain. I suspect that they're trying to show rivers flowing ...
2
votes
1answer
37 views
What's a reasonable flow rate/mass flux for a fumarole?
Obviously, there is going to be a large amount of variability, but what are some realistic values?
11
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1answer
358 views
Did the Geothermal Power Plant contribute to Pahoa's Lava Fissures?
There was lava in the area near the wells that the Puna Geothermal Venture facility created.
The plant has nine wells that run as deep as 8,000 feet, according to Wil Okabe, managing director for ...
3
votes
0answers
54 views
Is there a large undersea caldera in the Azores?
There looks like a large undersea circular feature (Google maps) about 120km across with its north edge on Sao Miguel Island and its south edge on Santa Maria Island.
Has any work been done to say ...
3
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0answers
33 views
Employment of Volcanologists and Petrologists
What industries or government departments hire volcanologists and igneous petrologists/geochemists in the United States?
4
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1answer
566 views
Causes of fluctuations in atmospheric oxygen in past 300 Mya
I have two questions based on the history of atmospheric oxygen levels depicted below.
Source: https://commons.wikimedia.org/wiki/File:Sauerstoffgehalt-1000mj2.png.
The notes below the chart explain ...
4
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0answers
62 views
Can a cryovolcanic eruption be as powerful as a normal volcanic eruption?
The most powerful volcanic eruption in recorded history was the 1815 eruption of Mount Tambora, an explosion equivalent to 33 billion tons of TNT.
Is there any way a cryovolcanic eruption could be as ...
2
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1answer
378 views
Volcanic activity in Taiwan, ever in recorded history, much chance in the near future?
News of Hawaii has got me thinking...
I've lived in Taiwan for many years and hiked many kinds geologically interesting mountain and seashore rock formations, seen steaming, sulfury fumaroles, even ...
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1answer
46 views
Haean, South Korea: is it of volcanic or meteor impact origin?
This is a layman's question. While looking for something I read in the news today, I stumbled upon the Haean region in South Korea (38°17'15.96"N, 128° 7'57.18"E) in Google Earth.
To me it looks ...
1
vote
1answer
58 views
How many extreme shifts in climate has Earth gone through in its existence?
As the Earth formed, it went through cycles of essentially hotter and colder periods. Extremely volcanic times and ice ages, in feedback loops contributing to one another. CO2 swinging from high to ...
3
votes
1answer
799 views
How vertically deep do lava conduits go?
I'll preface this with the truth and hope it doesn't disqualify the question but rather give context: after reading Journey to the Center of the Earth by Jules Verne, I am amazed at the prospect of ...
2
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0answers
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 ...
11
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2answers
191 views
How did CO₂ originate on Earth before there was life?
To start life there has to be $\ce{CO2}$.
$\ce{Solar energy + 6CO2 + 6H2O -> C6H12O6 (sugars) + 6O2}$
$C_6H_{12}O_{6} + O_2 \longrightarrow H_2O + {CO}_2 + \text{Energy}$
So to start this cycle, ...
10
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1answer
141 views
Would a volcanic winter trigger an oceanic “spring”?
There is large amounts of observations supporting the effects of volcanic eruptions on climate: A long term subtle warming effect due to $\ce{CO_2}$ and a short term, but more intense cooling effect ...
6
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1answer
860 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?
8
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1answer
260 views
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).
...
3
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0answers
238 views
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 ...
2
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1answer
140 views
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 ...
2
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0answers
56 views
How is tiltmeter data processed?
With what programs can inclinometer data be processed? And how is instrumental correction done?
3
votes
1answer
435 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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0answers
115 views
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 ...
2
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1answer
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 ...
8
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1answer
797 views
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, ...
3
votes
1answer
746 views
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?
