Posted on 03/18/2005 10:19:20 PM PST by Quix
Volcanoes beneath the Sea
A Fiery Birth
Last May, amazed scientists watched as lava and ash blasted through the surface of the Pacific Ocean and high into the air. They were getting a rare glimpse of a live eruption from an undersea volcano. How do these submarine volcanoes work?
"Fiery birth of a new Pacific island!" read the May 24 announcement from the Australian Commonwealth Scientific and Industrial Organization (CSIRO). CSIRO had sent a team of researchers to study the dormant undersea Kavachi volcano in the Solomon Islands east of Australia.
They discovered that the volcano was not dormant at all. Molten magma and ash were shooting more than 200 feet into the air, while plumes of steam and smoke rose thousands of feet above the ocean's surface.
Over the years, the material coming out of Kavachi had built up from the ocean floor, eventually rising over 3,000 feet until it broke through the water's surface and formed a small island. "We arrived to find waves breaking on the volcanic peak. Violent eruptions were taking place very five minutes," reported Brent McInnes, the expedition's chief scientist.
Kavachi belongs to the world of submarine volcanoes, which mostly do their erupting out of sight and occasionally form islands above the surface of the water. In the case of Kavachi, these "ephemeral islands" have formed at least 8 times in the past 60 years, only to recede under the water. These islands have reached more than 500 feet in length.
Underwater Eruptions
Kavachi's dimensions may pale next to famous above-ground volcanoes—from Mount St. Helens in Washington state to Mount Etna in Italy. But submarine volcanoes can become just as large and violent.
For instance, the undersea Loihi volcano in the Hawaiian Islands may be invisible at sea level, but it towers almost 10,000 feet above the ocean floor. That's taller than Mount St. Helens. During a 1996 eruption of Loihi, researchers recorded the temperature of the surrounding water at almost 400°F.
Some submarine volcanoes form where Earth's tectonic plates meet. For instance, Kavachi and the other Solomon Islands form about 30 kilometers north of where the Indo-Australian and Pacific plates meet in a jumble of smaller, "microplates." Where one plate is pushed—or subducted—beneath another, the bottom plate begins to melt and magma starts to rise through the overlying plate. This results in eruptions along rifts in the ocean floor.
Other submarine volcanoes form when tectonic plates move over a "hotspot" where magma punches through from below. This is what formed—and is still forming—the Hawaiian Islands.
Since these eruptions are surrounded by water, they behave differently than their land-based relatives. The lava that pours out onto the sea floor cools rapidly in the water. As a result it tends to shatter into sand and debris that begin to pile up in a sloping pattern. Unlike land-based lava flows, which bind to the mountains from which they come, submarine volcanoes build themselves up particle by particle. With each new eruption, more of the debris accumulates on the sides of the underwater mountain.
Those volcanoes—which are also called "seamounts"—may exist so far undersea that the weight of the water keeps their steam and gasses from escaping. In many cases, their volcanic activity is invisible at the ocean surface.
Around the World
Neither are they confined to the seismically active area covered by the Pacific Ocean. Researchers are monitoring submarine volcanoes from the coast of Oregon to the Mediterranean Sea.
The Caribbean also provides an underwater home to volcanic residents, one of which is named Kick-'em-Jenny. This submarine volcano, located just north of Grenada, has a base about 3 miles wide, it rises 4,300 feet from the ocean floor, and its top stands 525 feet below the ocean surface. It last erupted in 1990.
Of course, not all islands formed by underwater volcanoes remain underwater. Volcanic islands, most notably, the major islands in Hawaii have been naturally built around the active volcanoes at their centers. Hawaii's Big Island was constructed by five large volcanoes, including Mauna Loa, the largest active volcano on Earth.
Much of Japan and its surrounding islands emerged volcanically from the sea. Similarly, the West Indies islands in the Caribbean, the Azores in the Atlantic, and hundreds of islands in the Pacific have their origins in undersea eruptions.
http://www.freerepublic.com/focus/f-news/1363496/posts
about perhaps as many as 5,000 volcanoes being currently active in the Pacific. The article was treated derisively by the standard geologist naysayers on FR. Yet, here's an earlier article indicating more active volcanoes, if I'm understanding it right.
Certainly interesting times in the Pacific ring of fire, in any case.
John R, I did a quick check for duplicat--doesn't appear to be one.
Hope this helps your test. Blessings,
Aren't they the ones that fabricate news stories?
It still leaves unanswered the questions I posed early on that thread. I'll clarify here in case anyone can answer specifically:
Are there more active undersea volcanoes, or is our ability to detect them simply improving?
Is this merely the result of more funds flowing to geology, post-tsunami?
If there's more actual activity than there has been historically, where's the evidence that points to that conclusion?
That would be the New York Times of India.
They are ones SOME FREEPERS are convinced fabricate stories.
As near as I can tell, the major reason some FREEPERS believe that is because the Times of India publishes articles so far different from some FREEPERS' constructions on reality that they have no other recourse but to assume that the stories are fabricated.
I haven't seen proof one way or the other.
But in trying to check the under seas volcanoes story out, I found a lot more evidence that it was true--and none, per se, that it wasn't true.
It seems to me that there's a lot of snootiness on the part of some FREEPER naysayers--especially toward overseas publications. Certainly there's plenty to be desired on the part of many overseas publications. But who are we to talk--we have the New York Slimes and CNN and SEE BS.
I didn't find an emphatic, crystal clear proven answer to that question.
My IMPRESSION from reading a lot of sites about underseas volcanoes was that there's a lot more going on than anyone suspected. And, it appears that many have lighted off relatively recently. Certainly not paying attention to a phenomenon we didn't know existed would color the stats.
If you find a b etter answer to your question, please ping me.
Thanks for the clarity.
The article you mention was NOT from "The Times of India", an old and respectable source
It was from "India Daily" an apparently months-old webpage source specializing in fabricated stories designed to get web hits from apocalyptikook morons. These are the same people who reported on a hidden underground UFO base in the Himalayas.
It's astonishing that anyone with the brainpower to actually figure out how to make a post on FR could give credence to a "science" article like the "India Daily" one that doesn't cite a single scientist and heads the article with a fake graph purportedly showing underwater volcanoes going from 0 a few years ago to 8,000 now. (Helpful hint; the number of underwater volcanoes was NOT Zero when the graph purports they were.)
Yet, here's an earlier article indicating more active volcanoes, if I'm understanding it right.
You're not reading it right. It's a good article, about several underwater volcanoes that have been long known; I've been aware of Kavachi and Loihi for years. RESEARCH on underwater volcanism has exploded in the last few years, particularly deep on mid-ocean ridges (Kavachi and Loihi don't fall into that category, though); there's been no increase in underwater volcanoes.
Certainly interesting times in the Pacific ring of fire, in any case.
Looks pretty run-of-the-mill to me. Large earthquakes world-wide are really running well below average this year, again, too. No large volcanic eruptions for a long time, either.
You're welcome.
Best I can do with a range of other priorities! Sorry.
You seem to confuse healthy skepticism and logical unbiased thinking with "snootiness."
"India Daily" is worthless garbage beyond any shadow of a doubt.
Aren't they the ones that fabricate news stories?
"India Daily" is probably what he was thinking of. They're India's version of the Weekly World News and no one should consider their garbage to be legit news.
None, really.
Actually, frankly, we'd have no way of knowing what unusual underwater volcano activity would be. Even now we likely could only detect less than 10% of underwater eruptions, as opposed to maybe less than 1% ten years ago.
FMCDH(BITS)
I will note that AT THE TIME of the SUMATRAN QUAKE--THE FIRST DAY--I felt then that it was just a precursor. That a much bigger one will hid Indonesia most probably and at least within the Pacific rim within months.
I thought within 90 days. That turned out to be wrong.
But I'm convinced that we are not out of the woods yet by a long shot.
And, a recent published article by a group of serious qualified geologists examining the fault after the quake are still trying to sort through--did the quake leave the fault greatly relieved or greatly more locked up more dangerously.
My reading of that article was that they were hesitant to say, yet, but that it was beginning to appear that it left it more dangerously locked up at key points . . . one could say even, more dangerously cocked.
And then, this week, I got a doc via Dimitru Duduman's grandson who seems to also be graced with prophetic dreams/visions . . . asserting that Yellostone will light off sometime between 2005 and 2012. I believe that's true. The doc insisted that it would make the last time Yellowstone went off look like a burp. That's a sobering thought.
Certainly interesting times, regardless.
I later found essentially, if not identically the same article on the TIMES OF INDIA's website . . . as best as I can recall. I'm fairly certain of it. I'll try and go check now.
You are wrong in your assessment of my assessment.
I'm going on psychological nuances that most any super sensitive psychologist might be skilled in assessing.
It appears that there's no basis whatsoever to claim an increase in activity. Given that, you would do well not to expose yourself to the inevitable jeering that comes with making that suggestion.
Keep in mind that throughout human history, there have always been people who claim the world is about to come to an end. Their batting average is zero. Unless there's a very solid answer to the question of why this case might be different, it's good to remember that the world still exists despite legions who have claimed it would not.
Who knew?
FMCDH(BITS)
There's a lot of subduction zone off Sumatra, which is a big island, that didn't break....actually (due to logistical reasons, ease of getting to the site, Indian Government travel restrictions) that section was much more heavily studied by geologists..most prominently Kerry Sieh...than the section that did break.
It basically starts immediately south of the area of the December quake. It ruptured in a massive quake in 1833 and in a smaller quake that preceeded it in 1897. Based on the length of the area it would produce a quake in the 8.5-9 range, not bigger than the December quake. Even before the December quake it had been considered extremely dangerous.
It could pop tomorrow or in 20 years. That the December quake increased stress on it is a pretty valid theory (recently published in Nature.) The orientation of that segment would mean very small or no tsunami in India, Sri Lanka, and Thailand but would hit Indonesia very hard again (in a densely populated area) and also give NW Australia more of a hit. Potentially Madagascar too.
The odds of Yellowstone erupting in our lifetimes is vanishingly small. Despite what a lot of kook sites claim, there's no particular evidence the entire Caldera is getting ready to erupt.
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