Posted on 01/13/2004 5:35:54 AM PST by alloysteel
Palaeoceanographic data have been used to suggest that methane hydrates play a significant role in global climate change. The mechanism by which methane is released during periods of global warming is, however, poorly understood. In particular, the size and role of the free-gas zone below gas-hydrate provinces remain relatively unconstrained, largely because the base of the free-gas zone is not a phase boundary and has thus defied systematic description. Here we evaluate the possibility that the maximum thickness of an interconnected free-gas zone is mechanically regulated by valving caused by fault slip in overlying sediments. Our results suggest that a critical gas column exists below most hydrate provinces in basin settings, implying that these provinces are poised for mechanical failure and are therefore highly sensitive to changes in ambient conditions. We estimate that the global free-gas reservoir may contain from one-sixth to two-thirds of the total methane trapped in hydrate. If gas accumulations are critically thick along passive continental slopes, we calculate that a 5 °C temperature increase at the sea floor could result in a release of 2,000 Gt of methane from the free-gas zone, offering a mechanism for rapid methane release during global warming events.
To demystify what the above says:
http://www.newswise.com/articles/view/502756/
Scientists at the University of Wyoming may have discovered how massive amounts of carbon enter the atmosphere during periods of global warming.
In a paper published Jan. 8 in the journal Nature, UW Department of Geology and Geophysics graduate student Matthew Hornbach and professors Demian Saffer and Steve Holbrook propose that the source of the carbon is methane gas found beneath methane hydrate -- an ice-like substance consisting of frozen methane and water. Methane hydrate exists in vast quantities beneath the ocean floor and is believed to constitute the largest reservoir of organic carbon on Earth.
Hornbach, Saffer and Holbrook contend that a rise in ocean temperatures can convert the methane hydrate into methane gas. "Since methane is a greenhouse gas, substantial amounts of it released from beneath these hydrate deposits can contribute to global warming," Hornbach says.
For decades climate researchers have recognized that global warming events correspond with rapid spikes in atmospheric methane concentrations. But the UW scientists' discovery of widespread critically pressurized volumes of methane gas below continental margins may answer the often debated question of where the methane comes from and how it gets into the atmosphere so quickly.
Critically pressurized volumes of methane gas exist below many methane hydrate deposits, resulting in a potentially unstable ocean floor that is highly sensitive to changing conditions. Hornbach says any change in temperature or pressure at these critically pressured gas sites can cause hydrate to convert into methane gas. The highly pressurized gas can cause faults in the ocean floor to break apart, allowing the gas to escape.
"It's like a cork in a champagne bottle," he says. "If you shake up the champagne and build up enough pressure, the champagne bubbles can pop the cork."
Because these critically pressured gas volumes are found worldwide, Hornbach says large quantities of methane could be released during a global warming event.
"It is well documented that bottom-water temperatures in the ocean increase by approximately 5 degrees centigrade during periods of global warming," Hornbach says. "Our study indicates that perhaps as much as 2,000 gigatons (a single gigaton is one billion tons) of methane gas might escape from the ocean into the atmosphere during such warming events."
The UW scientists also contend that massive underwater landslides -- the relics of which sprawl across continental margins -- may be the direct result of ocean floor failures caused by overpressured methane gas.
Much of the project's data was collected at Blake Ridge in the Atlantic Ocean, located 300 miles off the coast of North Carolina. The scientists used soundwave technology to image beneath the ocean floor, Hornbach says, and dove some three kilometers below the surface of the Atlantic to find samples of methane gas leaks. The research was funded jointly by the U.S. National Science Foundation and the U.S Department of Energy.
LOL! Let me save the tax payers money. Planetary warming caused by increased sun activity causes release of methane gas which accounts for the warming first carbon later results seen in ice cores. Note, no run away greenhouse effect has been documented. Nor was man involved.
The article did fall short of the usual crap we see. I'm surprised they didn't say that increased warming do to man's release of greenhouse gasses could cause this catastrophic event. Hence the need for Kyoto. It's all Bush's fault don't you know.
That temperature spike may have been due to a huge methane release somewhere in the region of Iceland
Or, then again, maybe it was the Sun.
Any way to convert Methane Hydrate into oil?
I'll bet it's easy. Over fifty years ago South Africa was able to convert coal into gasoline.
I doubt if crude is going to get scarce. Oil companies only project their resources for about 5 or 10 years into the future and they really have no idea what the world supply is -- simply because they haven't looked everywhere in the world.
"Fuels to Drive our Future"
Although the technology exists for converting natural gas into liquid fuels, the cost is too high when the technology involves first converting natural gas into syngas. The costs for syngas-based fuels from natural gas, expressed as 1988 dollars per crude oil equivalent barrel, depends on the technology and assumed rate of return and vary as follows: (1) methanol from natural gas, $45 to $50/barrel; (2) methanol to gasoline, $60 to 68/ barrel; and (3) the Shell Middle Distillate Synthesis process, $58 to $64/ barrel (see Chapter 3 and Tables D-3 and D-4. The direct conversion routes have the potential of being more energy efficient and less expensive since they bypass the formation of syngas. However, the current level of development has not achieved the potential significant cost reductions. Gasoline from ARCO's REDOX process costs more than Mobil's MTG (fluidized bed) process (Schumacher, 1989~. An analysis of the cold flame oxidation route, showed that based on an optimistic design the cost of gasoline would be reduced only 7 to 15 percent (with zero cost for natural gas) compared to the conventional MTG technology (Fluor Corporation, 1988~. This analysis also indicated that the cold flame oxidation route did not have any overall thermal efficiency advantage. Liquid fuels from domestic natural gas are expensive because of the high value of domestic natural gas for conventional markets. For example, natural gas at $5/million Btu represents $33/barrel of the $60/barrel (10 percent discount rate) cost of MTG gasoline using the fluid bed reactor design. Even if a direct methane conversion process were developed that used 20 percent less natural gas, the cost of natural gas would represent $26/barrel of crude oil equivalent of the gasoline cost. Although Alaskan natural gas would be significantly less costly, higher capital and transportation costs for liquid fuels produced in Alaska would offset the gas cost advantage. Estimates show that a natural gas-to-methanol plant would cost 70 percent more to construct at Prudhoe Bay than at a U.S. Gulf Coast location. Also, shipping methanol to Southern California would cost about $40/barrel oil equivalent from Prudhoe Bay compared to $7/barrel from the U.S. Gulf Coast (California Fuel Methanol Study, 1989~.
Or just use the methane (recovered from the methane hydrate) directly, both as the feedstock and as the energy source to drive the synthesis.
It would be easier to do than converting to hydrogen. IIRC most vehicles can be converted to methane fuel easier than hydrogen.
I think the problem with the Arabs is that too many of the people in our government look to them, not as the enemy, but as their employers.
"For decades researchers have recognized that..."
"It is well documented that..."
"Our study indicates that perhaps as much as..."
"The scientists also contend that..."
Looks like its time again to re-post...
NOTES FOR UNDERSTANDING SCIENTIFIC PAPERS
INTRODUCTION
claim: "It has long been known that..."
reality: I haven't bothered to look up the original reference.
claim: "Of great theoretical and practical importance..."
reality: It was interesting to me.
claim: "While it has not been possible to provide definite answers to these questions..."
reality: The experiments didn't work out, but I figured I could at least get a publication out of it.
EXPERIMENTAL PROCEDURE
claim: "The W-Pb system was chosen as especially suitable to show the predicted behavior..."
reality: The fellow in the next lab had some already made up.
claim: "Three of the samples were chosen for detailed study..."
reality: The results on the others didn't make sense and were ignored.
RESULTS
claim: "Typical results are shown..."
reality: The best results are shown.
claim: "Although some detail has been lost in reproduction, it is clear from the original micrograph that..."
reality: It is impossible to tell from the micrograph.
claim: "Presumably at longer times..."
reality: I didn't take the time to find out.
claim: "The argreement with the pridicted curve is excellent..."
reality: Fair.
claim: "...good"
reality: Poor.
claim: "...satisfactory"
reality: Doubtful.
claim: "...fair"
reality: Imaginary.
claim: "...as good as could be expected considering the approximations made in the analysis"
reality: Nonexistent.
claim: "These results will be reported at a later date..."
reality: I might possibly get around to it sometime.
claim: "The most reliable values are those of Jones..."
reality: He was a student of mine.
DISCUSSION
claim: "It is suggested that..."
claim: "It is believed that..."
claim: "It may be that..."
reality: I think.
claim: "It is generally believed that..."
reality: A couple of other blokes think so too.
claim: "It might be argued that..."
reality: I have such a good answer to this objection that I shall now raise it.
claim: "Correct within an order of magnitude..."
reality: Wrong
claim: "It is to be hped that this work will stimulate further work..."
reality: This paper isn't very good, but neither are any of the others on this miserable subject.
ACKNOWLEDGEMENTS
claim: "Thanks are due to Joe Smith for assistance with the experiment and to John Brown for valuable discussions..."
reality: Smith did the work and Brown explained what it all meant.
--Boot Hill
Boy, I can't even read a piece about science without these guys butting in.
--Boot
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