Questions tagged [volcanology]

The properties and behaviour of volcanoes.

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6
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1answer
208 views

What is the mechanism for deep-sea volcanism of the Gakkel Ridge in the Arctic?

Related to an earlier question, What is the geochemical source for the helium detected in deep Arctic explosive eruptions?, where it is stated in the linked article that there is evidence of explosive ...
11
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1answer
848 views

What evidence is there for geological mechanisms that formed the Siberian traps flood basalt?

The Siberian Traps are the modern day remnants of the flood basalt event. Its eruptions is widely believed to be a major contributing factor of the Permo-Triassic extinction event. In reading ...
11
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1answer
157 views

What efforts have been made to separate the microseismic events related to wind-related ocean waves from the components of volcanic origin?

I have read the question What generates the microseism? and it's accompanying answer. In [#1, cited below], they use the azimuth values of seismographic activity on the flanks of the volcano ...
6
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1answer
394 views

Is the Cameroon Line still an active rift zone?

The Cameroon Line is described by the Oregon State University's Volcano World webpage What is known about the volcanoes of Cameroon? as a a chain of volcanoes extending from Annobon Island in the ...
10
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2answers
1k views

Why are alkali basalts found at rifting centres and on top of 'plumes', whereas MORBs are generally tholeiitic?

So I was essentially wondering why it was that the basalts on top of 'plumes' at 'hotspots' (sometimes called OIBs, ocean island basalts) and at continental rifting centres are enriched in alkaline ...
16
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1answer
432 views

Why won't Yellowstone explode?

From my understanding Yellowstone is a massive super-volcano, so why isn't it active? Where has its (correct me if I'm using the wrong term) hot-spot gone? Can it still erupt?
11
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1answer
1k views

Olympus Mons sized volcano on Earth?

The shield volcano Olympus Mons on Mars has the distinction of being the most massive single volcano in the solar system - this volcano, according to NASA, is 25km high with a diameter of over 600km - ...
10
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1answer
249 views

Why would magma have high amounts of nickel and chromium?

I am doing a research project on Mount Lamington and through my research I have found that its magma has unusually high amounts of chronium and nickel. What would cause this to happen? Is there ...
11
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1answer
131 views

What is the mechanism behind changes in oxidation state (of iron, for example) as magma rises?

From this answer, I learned that rising magma may change oxidation state, which I wasn't aware of. In [#1], the authors state in the abstract The conventional view holds that the oxidation state ...
9
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1answer
338 views

How does the composition of volcanic rock change as it makes its ascent towards the surface?

A schematic for the fluid mechanics of a volcano is represented below. Graciously borrowed from Figure 1 of the reference cited below From the caption of that figure: During explosive eruptions, ...
13
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1answer
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Why does the “Ring of Fire” pretty much define “Pacific Rim”

The Pacific Rim is pretty much defined by the so-called "Ring of Fire." It consists of the "stomping ground" for a disproportionate number of earthquakes and volcanoes, and the affected territory ...
9
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1answer
335 views

What are these “ship wrecks” (pictured) in the old volcano crater?

They consists of stone, of course, but have strange U cross section, as if they were the remaining of some ships without the head and tail section. Could anyone tell how have they formed? They almost ...
13
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1answer
1k views

What tectonic mechanisms cause the North and South Islands of New Zealand to be so geologically different?

New Zealand is a very active seismic and volcanic region of the Pacific Ring of Fire, on the boundary of the Australian and Pacific Plates; however, there is a difference between the 2 islands: ...
9
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1answer
133 views

What are the factors that dictate a given topology for seismometer placement around a volcano?

The image below (borrowed from [#1]) shows the topology of the seismometers around the volcano Stromboli. In the text, they explain the following: The seimometers were set on the flanks of the ...
11
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1answer
229 views

What happens to the higher frequency content of the tremors associated with a volcanic eruption?

From [1]: The main characteristics of volcanic tremor depend strongly on whether a volcano is erupting explosively and on the intensity of the event. Long before an eruption, tremor is ‘narrow-...
12
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1answer
180 views

How did this rock dome (pictured) form?

I saw this rock formation near Hveravellir, Iceland. It is probably of volcanic origin and looks like a dome. It is nearly symmetric and appears to consist of hardened lava maybe, with several very ...
12
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1answer
70 views

Why are titanium oxides lumped in with magnetite for the purposes of analyzing water bubble nucleation?

I was reading a bit about the fluid mechanics of volcanoes to further understand some of the dynamics of "magma wagging" from my earlier question. From [2]: Heterogeneous nucleation, in which the ...
8
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1answer
86 views

Are there measurement techniques that can help determine the exact geometry of a volcanic vent?

In a previous question What happens to the higher frequency content of the tremors associated with a volcanic eruption?, I asked about the high(er) frequency content of a volcanic eruption. In the ...
7
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1answer
153 views

Is there an earth science discipline, or subdiscipline, that only studies magma or lava?

I know volcanologists study volcanoes. Is there a subdiscipline that only studies maga or lava? A magmatologist?
11
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1answer
1k views

How does the sand appear on Hawaiian beaches

It's quite surprising to me that there's only one beach with black sand on Hawaii (maybe not exactly one beach, but it's only a very small fraction). The concern is, if the whole Hawaii is volcanic, ...
11
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1answer
2k views

Determining a rock age using volcanic ash layer

I wanted to know if volcanic ash deposits found in the geologic record are most useful in correlating the age of rock layers if the volcanic ash was distributed over a large area during a short period ...
10
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2answers
251 views

Is it possible to find the magma chambers that produce supervolcanos?

Supervolcanos have occurred in the recent geological past, but not within the past 74,000 years. Is it possible to find the magma chambers with no previous history of supervolcanic activity that are ...
11
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1answer
482 views

Are mantle plumes distributed around the core randomly or in a known pattern?

Background: The theory of mantle plumes is useful (although controversial) in explaining the occurrence of intra-plate volcanoes. The website here suggests that "hotspots" exist in fixed locations ...
8
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1answer
954 views

What causes a volcano? [closed]

Inspired by the question, How does one measure what causes earthquakes?, I'd like to know what causes another great geological phenomenon - volcanoes?
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0answers
100 views

Any other fumarolic ice caves in the literature? [closed]

I study the fumarolic ice caves of Erebus Volcano, and am looking for published research on similar sorts of caves. My criteria for a "fumarolic ice cave" are that it must be: A gas-filled void space ...