A volcanic eruption is measured in two constants--gas and viscosity. For clearance, low viscosity is like squirting water off a nozzle, whereas high viscosity is like squirting caramel off a nozzle, which takes more effort to do, which ultimately makes it more dangerous.
In geology, there are four different kinds of volcanic eruptions:
- Low Gas + Low Viscosity = A quiet lava flow.
- High Gas + Low Viscosity = A fire fountain eruption.
- Low Gas + High Viscosity = A dome-building eruption. (This sort of eruption doesn't reach critical right away.)
- High Gas + High Viscosity = A Ring of Fire explosion.
These sorts of eruption are impressive enough on land, but in the event of someone doing some serious worldbuilding, this question puts three of the four types underwater. Type #1 has long been confirmed to happen underwater, but the oceanic differences in temperature and pressure have produced a different result called "pillow lava".
Is it possible for eruption types numbers 2, 3 and 4 to occur underwater? If yes, then would the oceanic differences in temperature and pressure make them look and act differently from how they have acted above sea level?
The stereotypical eruption often portrays the volcano spewing streams of lava, ash and ejecting massive boulders, and earlier today, I realized I had no clue what said rockier ejections were called or if they're even a real thing. I know ash sometimes forms more solid tuff, but that's not really what I'm looking for.
This is the best tl;dr I could make, original reduced by 78%. (I'm a bot)
> A study of a New Zealand volcano suggests that a volcanic system's response to tidal forces could provide a tool for predicting a certain type of eruption.
> PROVIDENCE, R.I. - Just before a surprise eruption of New Zealand's Ruapehu volcano in 2007, seismic tremor near its crater became tightly correlated with twice-monthly changes in the strength of tidal forces, a new study has found.
> The research, published in the journal Scientific Reports, suggests that signals associated with tidal cycles could potentially provide advanced warning of certain types of volcanic eruptions.
> "We wanted to take a different angle with this study and look at whether there's some detectable signal associated with tidal forces that can tell us something about a volcano's criticality."
> The model suggests that when the pressure of the gas pocket reaches a critical level - a level at which a steam eruption is possible - the differing stresses associated with changing tidal forces are enough to change the amplitude of tremor.
> So a tidal signal could be a way of predicting steam-driven eruptions, which are otherwise hard to predict.
Summary Source | FAQ | Feedback | Top keywords: tidal^#1 research^#2 eruption^#3 seismic^#4 tremor^#5
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In my home state in the US (California) it would either be forest fires or earthquakes. We grow up doing earthquake drills in school and a nearby soccer/football team is called the San Jose Earthquakes. I am interested in learning about any cultural views of these disasters or ways that people prepare.
I'm currently debating with my professor over the...structural specifics of how a massive volcano in the Cape Verdes laterally erupted about a hundred thousand years ago.
I'm arguing that few if any material is left on the island at surface level from the initial eruption, because the eruption took place immediately after an immense 300km^3 landslide that excavated out the summit and much of the cone of the volcano, leaving behind a 20km horsheshoe-shaped cliff headwall from the landslide that would have at the time been about 3 km tall. I'm saying that between that headwall and a laterally oriented eruption, little material from the post-collapse plinian-type eruption would be findable in the modern day. But I'm certainly open for a search....
Anyway, the only video I know of, of a lateral burst eruption is this incomplete clip of the Mt. St. Helens eruption. Are there any longer, more complete videos that show the entire eruption right after the collapse event? In the case of Mt. St. Helens or any other massive eruptive-volcanic landslides.
(The ground level inside the caldera from 100,000 years ago has since been buried with 1-2km of new volcanic material).
