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Arthur T Knackerbracket has processed the following story:
Over the past decade, the Japan Coast Guard has occasionally spotted patches of milky blue water about 5 kilometers (3 miles) north of South Iwo Jima island. The discolored water has been a subtle reminder that the summit of an active volcano—Fukutoku-Okanoba—lurks about 25 meters (80 feet) below the water surface.
On August 13, 2021, there was much more than just discolored water. A photograph taken by a Coast Guard aircraft flying near the volcano showed a towering plume of gas rising several kilometers into the air—a sure sign that explosive “Surtseyan” eruptions were happening.
Satellite observations and follow-up flights filled in more details. The Japanese geostationary satellite Himawari 8 was among the first satellites to observe the eruption, showing its beginning stages at about 21:00 UTC (6 a.m. local time) on August 12, 2021. When NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) sensor on the Terra satellite acquired its first image of the event on August 13, it showed a bright plume—likely steam and volcanic gases—streaming from the vent and stretching hundreds of kilometers to the west.
The longevity and vigor of the plume surprised some scientists. “What was remarkable about this eruption is that it went straight from being a submarine event to an eruption cloud reaching the lower boundary of the stratosphere,” explained Andrew Tupper, a meteorologist with Natural Hazards Consulting and a specialist in hazards to aviation. “That is not very common for this type of volcano. We normally see lower-level plumes from submarine eruptions.”
[...] “Aviation and marine warning systems for remote submarine volcanoes are still very much developing,” said Tupper. “Combining cutting-edge satellite data with surface observations gives us the best possible chance to respond in time.”
(Score: 2) by ElizabethGreene on Sunday August 29 2021, @02:53PM (4 children)
25 meters isn't that far below the surface. I'd be curious to know if it's going to make a new island.
Asking the internet, I found this here: https://volcano.si.edu/volcano.cfm?vn=284130 [si.edu]
I assume the "pumice island" is floating rock and not attached to the underlying volcano.
(Score: 1, Informative) by Anonymous Coward on Sunday August 29 2021, @07:44PM (3 children)
Correct. A pumice raft [wikipedia.org] is a mass of free-floating pumice commonly produced by maritime volcanoes.
(Score: 3, Insightful) by MIRV888 on Monday August 30 2021, @07:01AM (2 children)
Just to be clear. Pumice is less dense than water and floats?
I did not know that.
(Score: 1, Insightful) by Anonymous Coward on Monday August 30 2021, @12:31PM (1 child)
Think of it as foamed lava.
(Score: 0) by Anonymous Coward on Tuesday August 31 2021, @08:05AM
It also makes a good foot file.
(Score: 2, Funny) by Anonymous Coward on Sunday August 29 2021, @06:13PM
Underwater volcanos are one of the known sources of Godzilla-type creatures. He'd better be wearing a mask this time unless he wants to get the Delta variant.
(Score: 3, Interesting) by MIRV888 on Monday August 30 2021, @06:58AM
It would appear that 80 feet of water doesn't mean a whole lot to a serious undersea eruption. My totally non-professional opinion is all the steam created drove the ash / gas cloud so high.