Posted on 10/21/2003 4:15:50 PM PDT by NormsRevenge
WASHINGTON (Reuters) - Methane bubbles from the sea floor could, in theory, sink ships and may explain the odd disappearances of some vessels, Australian researchers reported on Tuesday.
The huge bubbles can erupt from undersea deposits of solid methane, known as gas hydrates. An odorless gas found in swamps and mines, methane becomes solid under the enormous pressures found on deep sea floors.
The ice-like methane deposits can break off and become gaseous as they rise, creating bubbles at the surface.
David May and Joseph Monaghan of Monash University in Australia said they had demonstrated how a giant bubble from one of these deposits could swamp a ship.
"Sonar surveys of the ocean floor in the North Sea (between Britain and continental Europe) have revealed large quantities of methane hydrates and eruption sites," May and Monaghan wrote in their report, published in the American Journal of Physics.
"A recent survey revealed the presence of a sunken vessel within the center of one particularly large eruption site, now known as the Witches Hole."
"One proposed sinking mechanism attributes the vessel's loss of buoyancy to bubbles of methane gas released from an erupting underwater hydrate," they wrote." The known abundance of gas hydrates in the North Sea, coupled with the vessel's final resting position and its location in the Witches Hole, all support a gas bubble theory."
No one has ever seen such an eruption and no one knows how large the bubbles coming off a methane deposit would be.
May and Monaghan created a model of a single large bubble coming up under a ship. They trapped water between vertical glass plates, launched gas bubbles from the bottom and used a video camera to record what happened to an acrylic "hull" floating on the surface.
"Whether or not the ship will sink depends on its position relative to the bubble. If it is far enough from the bubble, it is safe," they wrote.
"If it is exactly above the bubble, it also is safe, because at a stagnation point of the flow the boat is not carried into the trough. The danger position is between the bubble's stagnation point and the edge of the mound where the trough formed," they concluded. ).
Dog!!!! Hah!!!! I promise there is NOTHING worse that "cat gaseous emissions".
Actually, the best theory on the "mysterious disappearances" in the Bermuda Triangle is that there's nothing mysterious going on at all.
People hoping to make money selling books or lecture tours have constantly exaggerated (or simply made up) the number and type of ships/planes lost in that area. In truth, the events in that area aren't out of lne for what one would expect given the amount of traffic it carries, and the storms and other natural hazards which are common in the area.
The whole "Bermuda Triangle" craze was kickstarted by Charles Berlitz's 1974 sensationalistic mass-market book, "The Bermuda Triangle". The problem is that Berlitz played fast and loose with a lot of facts in order to play up the "mysterious" slant on ordinary events. For example, he includes a plane that disappeared when its "destination" was Jamaica. What he "forgets" to mention is that the plane actually went down while flying from the Azores (in Portugal) to *Canada*. Needless to say, that's pretty damned far from the Bermuda Triangle. The only "connection" to the Bermuda Triangle is that the plane *would* have gone on to fly to Jamaica after stopping over in Canada, had it not crashed before it even got to Canada in the first place.
And planes/ships he reports having vanished "without a trace" often actually disappeared in hurricane-force winds, or after distress calls reporting ordinary accidents or failures, etc.
Hmmm, what did you say about the bubble?
"You are a fluke of the universe. You have no right to be here. And whether you realize it or not the universe is laughing behind your back." -- the Deteriorata.
Detergent to the rescue. No more stagnation points, no more troughs. Fill the bilge with Dawn and, when the ocean sounds like champagne, dump it.
AFAIK, they don't do it often (maybe they can't even stand themselves). Think about how bad cat food smells (especially anything with fish in it) BEFORE "processing".
You're right, I had no idea. The ocean floor is of course more vast than the land we know and there's a lot of pressure down there.
Fascinating. Thanks for the ping! ;-)
Whale farts!
The area shown in the map on an earlier post is conincident with significant North Sea oil, natural gas, and gas condensate production. It is no surprise that methane degassing occurs there.
In the Santa Barbara Channel, off of the coast of California, there is an area near "Coal Oil Point" with prolific natural gas (95%+ methane) seeps. Two 100 ft x 100 ft steel pyraminds were lowered on to the seafloor to capture gas eminating from one very active area. These two underwater tents capture enough natural gas to power the domestic natural gas needs for a city of 25,000 people each and every day. I have been on boats in the midst of these seepages. It is like floating in a oily Coca Cola. And I lived to tell about it!
It didn't explode when we tossed our butts over the side, either.
My $.02
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