Frozen methane

Figure 25.1 indicates that a substantial amoimt of carbon is trapped in marine sediments as frozen methane. This gas is produced in the surfece sediments by methanogens from metabolism of detrital organic matter and abiotically in more deeply buried sediments. At sufficiently low temperatures, the methane becomes encased in a cage of water molecules, fitrming a solid gas hydrate. As shown in Figure 25.3, the stability... 

Natural gas is a hydrocarbon of low molecular weight consisting of about 85% methane (CH ), which is recovered as an underground gas in areas where petroleum is found. It is also economically produced by conversion of crude oil to gas. Possible future sources of a hydro-gen-based fuel are large frozen methane deposits recently found on ocean bottoms. 

Blunier T (2000) Frozen methane escapes from the sea floor. Science... 

In addition to these direct effects, there are also indirect consequences. One consequence is that, as the oceans warm, they absorb less C02 the other is that, as the Canadian, Siberian, and Alaskan permafrost melts, the rotting organic matter will release vast amounts of C02 and methane. The rising C02 concentration of the atmosphere also reduces the pH of the oceans. In addition, about 10 teratons of carbon (tera = 1012) are stored in the frozen methane hydrates of the Arctic regions, which will also be released if the ice melts. 

Oxygen implantation in frozen methane does not produce the "expected" CO and CO2. N implantation in frozen mixtures H20 CH4 produces a X-OCN band but implantation of O in frozen mixtures H20 N2 does not. ... 

IVIethane is the simplest hydrocarbon, but it has some unusual behaviors. One of these is the ability to form a clathrate, which is an unusual type of matter in which molecules of one substance form a cage around molecules of another substance. For instance, water molecules can form a latticework around methane molecules to form frozen methane hydrate, possibly one of the biggest reservoirs of fossil fuel on earth. 

Frozen methane is found on the ocean floor. Formed by animals and decaying plant life, there are large pockets of oil and natural gas all over the earth. Methane hydrate forms when methane from one of these pockets under the ocean seeps up through the sea sediments. When the gas reaches the ocean floor, it expands and freezes. Vast regions of the ocean floor are covered by such ice fields. 

Figure 12.30 Cubic closest packing of frozen methane. Only one CH4 molecule is shown.

Solid, frozen methane deposits at the bottom of the oceans may become gaseous as the ocean warms, and the gaseous methane would be released into air. This would increase warming even more. 

Burning ice . The ice is frozen methane clathrate, which can be set on fire... 

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