Suggested mechanisms for the latter include large or multiple bolide impact events, increased volcanism, coal / gas fires and explosions from the Siberian Traps, and sudden release of methane clathrate from the sea floor ; gradual changes include sea-level change, anoxia, increasing aridity, and a shift in ocean circulation driven by climate change.

Some of the most severe fluctuations, such as the Paleocene-Eocene Thermal Maximum, may be related to rapid climate changes due to sudden collapses of natural methane clathrate reservoirs in the oceans.

Methane clathrate ( CH < sub > 4 </ sub >• 5. 75H < sub > 2 </ sub > O ), also called methane hydrate, hydromethane, methane ice, fire ice, natural gas hydrate, or gas hydrate is a solid clathrate compound ( more specifically, a clathrate hydrate ) in which a large amount of methane is trapped within a crystal structure of water, forming a solid similar to ice.

Originally thought to occur only in the outer regions of the Solar System where temperatures are low and water ice is common, significant deposits of methane clathrate have been found under sediments on the ocean floors of Earth.

The ice-core methane clathrate record is a primary source of data for global warming research, along with oxygen and carbon dioxide.

The average methane clathrate hydrate composition is 1 mole of methane for every 5. 75 moles of water, though this is dependent on how many methane molecules " fit " into the various cage structures of the water lattice.

One litre of methane clathrate solid would therefore contain, on average, 168 litres of methane gas ( at STP ).

The most common is dominated (> 99 %) by methane contained in a structure I clathrate and generally found at depth in the sediment.

The clathrates in these deep deposits are thought to have formed in situ from the microbially produced methane, as the δ < sup > 13 </ sup > C values of clathrate and surrounding dissolved methane are similar.

However, it is also thought that fresh water used in the pressurization of oil and gas wells in permafrost and along the continental shelves world wide, combine with natural methane to form clathrate at depth and pressure, since methane hydrates cannot form, initially, in salt water.

Part of the rotational-vibrational spectrum of methane ( CH < sub > 4 </ sub >) gas ( from Fourier transform infrared spectroscopy | FTIR ), showing the presence of P -, Q-and R-branches ( purple, top ) and a simulation in PGOPHER ( black, bottom ).

Barucci and colleagues compared Sedna's spectrum with that of Triton and detected weak absorption bands belonging to methane and nitrogen ices.

According to the orbital hybridisation theory, the valence electrons in methane should be equal in energy but its photoelectron spectrum shows two bands, one at 12. 7 eV ( one electron pair ) and one at 23 eV ( three electron pairs ).

The decrease in atmospheric methane that occurred at that time, as recorded in ice cores, was 2-4 times more rapid than any other decrease in the last half million years, suggesting a unique mechanism was at work.

Gas hydrates have been sampled at the Amsterdam and Kazan mud volcanoes, and high methane levels have been recorded above the seafloor.

In November, 1776, he found methane at Lake Maggiore, and by 1778 he managed to isolate methane.

Release or burning of methane would of course at least partially offset the obtained sequestration result – except when the gas is allowed to escape into the atmosphere in significant quantities: methane has a higher global warming potential than CO < sub > 2 </ sub >.

After an oil drilling operation in 1903 in Dexter, Kansas, produced a gas geyser that would not burn, Kansas state geologist Erasmus Haworth collected samples of the escaping gas and took them back to the University of Kansas at Lawrence where, with the help of chemists Hamilton Cady and David McFarland, he discovered that the gas consisted of, by volume, 72 % nitrogen, 15 % methane ( a combustible percentage only with sufficient oxygen ), 1 % hydrogen, and 12 % an unidentifiable gas.

An unconfirmed source states that they breathe a " primordial reducing atmosphere " mainly composed of methane and ammonia, and are culturally paranoid, at least by human standards.

96 tonnes of methane and oxygen would be needed to send the Earth Return Vehicle on a trajectory back home at the conclusion of the surface stay, the rest would be available for Mars rovers.

The simplest paraffin molecule is that of methane, CH < SUB > 4 </ SUB >, a gas at room temperature.

As the Sun was notably weaker at the time, the Earth's climate may have relied on methane, a powerful greenhouse gas, to maintain surface temperatures above freezing.

* March 18 – Ten miners die in a methane gas explosion at Golborne Colliery near Wigan, Lancashire.

Methane-air mixtures become flammable only when the methane concentration exceeds 5 %, at which point the mixtures also become explosive.

They are composed of about 100 species of vermiform creatures and live in thin tubes buried in sediments at ocean depths from 100 to 10, 000 m. They can also be found in association with hydrothermal vents, methane seeps, with sunken plant material or whale carcasses.

The chamber has a quadrupole and can be filled-up with reaction ( or collision ) gases ( ammonia, methane, oxygen or hydrogen ), with one gas type at a time or a mixture of two of them, which reacts with the introduced sample, eliminating some of the interference.

Recently, a clay-methane hydrate intercalate was synthesized in which a methane hydrate complex was introduced at the interlayer of a sodium-rich montmorillonite clay.

Above this zone methane is only present in its dissolved form at concentrations that decrease towards the sediment surface.

In some regions ( e. g., Gulf of Mexico ) methane in clathrates may be at least partially derived from thermal degradation of organic matter, dominantly in petroleum.

Since methane clathrates are stable at a higher temperature than liquefied natural gas ( LNG ) (− 20 vs − 162 ° C ), there is some interest in converting natural gas into clathrates rather than liquifying it when transporting it by seagoing vessels.

In experimental work at University of Alaska Fairbanks, a 1000-litre digested using psychotropics harvested from " mud from a frozen lake in Alaska " has produced 200 – 300 liters of methane per day, about 20 – 30 % of the output from dig esters in warmer climates.

< references >" Quantification of methane in humid air and exhaled breath using selected ion flow tube mass spectrometry " Dryahina K., Smith D., Španěl P .; Rapid Communications in Mass Spectrometry 24 ( 2010 ) pp1296 – 1304 .</ references >

Above 900 K ( 630 ° C / 1160 ° F ), carbon monoxide becomes the dominant carbon-carrying molecule in the planet's atmosphere ( rather than methane ).

Methyl group is an alkyl derived from methane, containing one carbon atom bonded to three hydrogen atoms — CH < sub > 3 </ sub >.

For example, the acidity of the methyl groups in acetone (( CH < sub > 3 </ sub >)< sub > 2 </ sub > CO ) is about 10 < sup > 20 </ sup > more acidic than methane.

The experiment used water ( H < sub > 2 </ sub > O ), methane ( CH < sub > 4 </ sub >), ammonia ( NH < sub > 3 </ sub >), and hydrogen ( H < sub > 2 </ sub >).

The Haber process produces ammonia ( NH < sub > 3 </ sub >) from methane ( CH < sub > 4 </ sub >) gas and molecular nitrogen ( N < sub > 2 </ sub >).

Spacecraft observations showed that the gases ejected from the nucleus were 80 % water vapor, 17 % carbon monoxide and 3 – 4 % carbon dioxide, with traces of hydrocarbons although more recent sources give a value of 10 % for carbon monoxide and also include traces of methane and ammonia.

* Hydrofluorocarbons ( HFCs ): when derived from methane, ethane, propane, and butane, these compounds have the respective formulae CF < sub > m </ sub > H < sub > 4-m </ sub >, C < sub > 2 </ sub > F < sub > m </ sub > H < sub > 6-m </ sub >, C < sub > 3 </ sub > F < sub > m </ sub > H < sub > 8-m </ sub >, and C < sub > 4 </ sub > F < sub > m </ sub > H < sub > 10-m </ sub >, where m is nonzero.

This is about equivalent to methane emission into the atmosphere and accounts for ~ 1 / 3 of all hydrocarbons released into the atmosphere.

In modern science, it is generally accepted that most ignes fatui are caused by the oxidation of phosphine ( PH < sub > 3 </ sub >), diphosphane ( P < sub > 2 </ sub > H < sub > 4 </ sub >), and methane ( CH < sub > 4 </ sub >).

Coenzyme M, CH < sub > 3 </ sub > SCH < sub > 2 </ sub > CH < sub > 2 </ sub > SO < sub > 3 </ sub >< sup >-</ sup >, is the precursor to methane ( i. e. natural gas ) via the process of methanogenesis.

Impeded by further floods, ( 23 August 1837, 3 November 1837, 20 March 1838, 3 April 1840 ) fires and leaks of methane and hydrogen sulphide gas, the remainder of the tunnelling was completed in November 1841, after another five and a half years.

This is an attractive hypothesis because of the abundance of CH < sub > 4 </ sub > ( methane ) and NH < sub > 3 </ sub > ( ammonia ) present in hydrothermal vent regions, a condition that was not provided by the Earth's primitive atmosphere.

LPG, vaporised and at atmospheric pressure, has a higher calorific value ( 94 MJ / m < sup > 3 </ sup > equivalent to 26. 1kWh / m < sup > 3 </ sup >) than natural gas ( methane ) ( 38 MJ / m < sup > 3 </ sup > equivalent to 10. 6 kWh / m < sup > 3 </ sup >), which means that LPG cannot simply be substituted for natural gas.

Although most marine biogenic methane is the result of carbon dioxide ( CO < sub > 2 </ sub >) reduction, a small amount is derived from acetate ( CH < sub > 3 </ sub > COO < sup >-</ sup >) fermentation .< ref >

HALOE uses solar occultation to measure simultaneous vertical profiles of ozone ( O < sub > 3 </ sub >), hydrogen chloride ( HCl ), hydrogen fluoride ( HF ), methane ( CH < sub > 4 </ sub >), water vapor ( H < sub > 2 </ sub > O ), nitric oxide ( NO ), nitrogen dioxide ( NO < sub > 2 </ sub >), temperature, aerosol extinction, aerosol composition and size distribution versus atmospheric pressure at the Earth ’ s limb.

The search for stable carbocations led to the discovery of protonated methane which was stabilized by superacids, like FSO < sub > 3 </ sub > H-SbF < sub > 5 </ sub > (" Magic Acid ").

Chartered by entrepreneur Lowell Harrelson and Long Island mob boss Salvatore Avellino, it set sail on March 22 from Islip, New York, escorted by the tugboat Break of Dawn and carrying 3, 168 tons of trash headed for a pilot program in Morehead City, North Carolina, to be turned into methane.

Liquid methane has 3. 2 times the energy density of liquid hydrogen and is easier to store.

It was shown that at 140 ° C ( 284 ° F ), FSO < sub > 3 </ sub > H – SbF < sub > 5 </ sub > will convert methane into the tertiary-butyl carbocation, a reaction that begins with the protonation of methane :< ref >