From CAGE – Center for Arctic Gas Hydrate, Climate and Environment
New source of methane discovered in the Arctic Ocean
Methane, a highly effective greenhouse gas, is usually produced by decomposition of organic material, a complex process involving bacteria and microbes.
But there is another type of methane that can appear under specific circumstances: Abiotic methane is formed by chemical reactions in the oceanic crust beneath the seafloor.
New findings show that deep water gas hydrates, icy substances in the sediments that trap huge amounts of the methane, can be a reservoir for abiotic methane. One such reservoir was recently discovered on the ultraslow spreading Knipovich ridge, in the deep Fram Strait of the Arctic Ocean. The study suggests that abiotic methane could supply vast systems of methane hydrate throughout the Arctic.
The study was conducted by scientists at Centre for Arctic Gas Hydrate, Environment and Climate (CAGE) at UiT The Arctic Univeristy of Norway. The results were recently published in Geology online and will be featured in the journal’s May issue.
Previously undescribed
“Current geophysical data from the flank of this ultraslow spreading ridge shows that the Arctic environment is ideal for this type of methane production. ” says Joel Johnson associate professor at the University of New Hampshire (USA), lead author, and visiting scholar at CAGE.
This is a previously undescribed process of hydrate formation; most of the known methane hydrates in the world are fueled by methane from the decomposition of organic matter.
“It is estimated that up to 15 000 gigatonnes of carbon may be stored in the form of hydrates in the ocean floor, but this estimate is not accounting for abiotic methane. So there is probably much more.” says co-author and CAGE director Jürgen Mienert.
Life on Mars?
NASA has recently discovered traces of methane on the surface of Mars, which led to speculations that there once was life on our neighboring planet. But an abiotic origin cannot be ruled out yet.
On Earth it forms through a process called serpentinization.
“Serpentinization occurs when seawater reacts with hot mantle rocks exhumed along large faults within the seafloor. These only form in slow to ultraslow spreading seafloor crust. The optimal temperature range for serpentinization of ocean crust is 200 – 350 degrees Celsius.” says Johnson.
Methane produced by serpentinization can escape through cracks and faults, and end up at the ocean floor. But in the Knipovich Ridge it is trapped as gas hydrate in the sediments. How is it possible that relatively warm gas becomes this icy substance?
“In other known settings the abiotic methane escapes into the ocean, where it potentially influences ocean chemistry. But if the pressure is high enough, and the subseafloor temperature is cold enough, the gas gets trapped in a hydrate structure below the sea floor. This is the case at Knipovich Ridge, where sediments cap the ocean crust at water depths up to 2000 meters. ” says Johnson.
Stable for two million years
Another peculiarity about this ridge is that because it is so slowly spreading, it is covered in sediments deposited by fast moving ocean currents of the Fram Strait. The sediments contain the hydrate reservoir, and have been doing so for about 2 million years.
” This is a relatively young ocean ridge, close to the continental margin. It is covered with sediments that were deposited in a geologically speaking short time period -during the last two to three million years. These sediments help keep the methane trapped in the sea floor.” says Stefan Bünz of CAGE, also a co-author on the paper.
Bünz says that there are many places in the Arctic Ocean with a similar tectonic setting as the Knipovich ridge, suggesting that similar gas hydrate systems may be trapping this type of methane along the more than 1000 km long Gakkel Ridge of the central Arctic Ocean.
The Geology paper states that such active tectonic environments may not only provide an additional source of methane for gas hydrate, but serve as a newly identified and stable tectonic setting for the long-term storage of methane carbon in deep-marine sediments.
Need to drill
The reservoir was identified using CAGE’s high resolution 3D seismic technology aboard research ressel Helmer Hanssen. Now the authors of the paper wish to sample the hydrates 140 meters below the ocean floor, and decipher their gas composition.
Knipovich Ridge is the most promising location on the planet where such samples can be taken, and one of the two locations where sampling of gas hydrates from abiotic methane is possible.
” We think that the processes that created this abiotic methane have been very active in the past. It is however not a very active site for methane release today. But hydrates under the sediment, enable us to take a closer look at the creation of abiotic methane through the gas composition of previously formed hydrate.” says Jürgen Mienert who is exploring possibilities for a drilling campaign along ultra-slow spreading Arctic ridges in the future.
###
Discover more from Watts Up With That?
Subscribe to get the latest posts sent to your email.
> Methane, a highly effective greenhouse gas, is usually produced
> by decomposition of organic material
That’s a weird opening sentence. Wouldn’t it be more relevant to say “Methane, an extremely useful low-CO2 fuel & organic feedstock, is usually produced by decomposition etc…” ?
Joseph Borsa, just above, hit it right on the nose. My own understanding of what Thomas Gold was saying was that the oil we pump and use is a product of abiotic methane percolating upwards through the layers of sediments containing the remaining raw materials necessary to create petroleum.
The sediments are, obviously, mostly plankton rather than dinosaurs, but the two together can, indeed, account for the enormous volumes (masses for the terminally anal) of hydrocarbons available for present human consumption.
It’s not an either/or proposition; the hypothesis is that biotic oil precursors laid the groundwork for the amazingly large amount of liquid hydrocarbons that underpin our modern lives.
Larry nails it. I think the confusion results from missunderstanding the word ‘fossil’ in the context of fossil fuel.
A fossil is a structure, usually cellular, provided by an organism, which is then mineralized by substitution and replacement or enrichment. When wood is ‘petrified’ by the replacement of carbohydrate cellulose structures with hydrated silica to form opalized wood, few people would claim that living trees in the distant past were composed of silica. We don’t see any such trees now. The silica has precipitated into the cell structure.
When fossilized wood is found in coal beds it is an easy presumption that the fossil which is now mineralized with carbon, had as a source of carbon the wood itself since that is what we see in the modern world: trees made of carbon molecules. This overlooks the distinct possibility that the mineralizing carbon has precipitated from methane by dehydration, which has enriched the carbon content of the deposit. THIS describes fossilization. Biotic plus abiotic=coal. Most coal beds are saturated with methane, carbondioxide and water.
C6H12O6+CH4+CO2=H2O+coal.
Petroleum is even more elusive conceptually as a fossil since there are no architectural structural organisms to observe and relate to as having been ‘fossilized’ by deposition. If the biotic constituent of the sediment acts as a catalyst or seed for the ‘mineralization’ of methane into ‘rock oil’, that oil, being liquid, would be free to migrate from source to reservoir depending on how tight the stuctures are. Once again biotic plus abiotic is a possible alternative. I distinctly remember my geology professor years ago stating that we don’t really know where oil comes from, we only know where to find it.
“Things fall apart: it’s scientific”
-Talking Heads (Wild, Wild Life)
In the fossil fable of hydrocarbon origins things don’t fall apart. Carbohydrates from dead things instead get preserved in the sediments of shallow inland seas during step one, while in step two “a miracle occurs” when they are upgraded into hydrocarbons:
http://www.pnas.org/content/99/17/10976.long
And that’s the balanced chemical equation for the transformation of dead stuff into “fossil fuels”:
dead stuff + then a miracle occurs = hydrocarbon species
It’s not scientific, because dead things spontaneously fall apart. Dmitri Mendeléev knew that already in 1877:
“The capital fact to note is that petroleum was born in the depths of the earth, and it is only there that we must seek its origin.”
The first microbes were probably built and powered by hydrocarbons. Their gas-guzzling descendants infest the planet today, from pole to pole, from sediment to surface, and in the deepest rocks that we’ve managed to drill into the crust. Without their incessant activity, the surfaces of the oceans would be coated in a thick layer of oil and photosynthesis would be impossible as a consequence. In fact, it wouldn’t have evolved in the first place without microbes to clean up the huge volume of oil that springs from natural leaks.
Microbes today still consume more hydrocarbons than we do. Developing an insatiable appetite for “fossil fuels” before photosynthesis evolved is just another miracle in the story.
there was a convincing suggestion many years ago that a massive release of methane would explain the disappearance of the squadron of aeroplanes and ships in the Bermuda triangle. Planes ignited cloud of gas and ships could no longer float.
Abiotic methane has been well established geology for over two decades. The debate over whether themsource is primordial escape from the mantle or from serpinitization of ultramafic rockmis largely settled in favor of the latter, although there is more than one synthesis pathway. In fact the flaming seeps in Turkey that Pliny thenElder wrote about turnnout to be abiotic. What is unusual about this new discovery is Framm Strait conditions that allow its accumulation as methane hydrate. But unless the encasing sediments are sand, there is no method known even conceptually to extract them. See essay Ice that Burns for details.
There is no evidence for abiotic petroleum. Period. Gold’s theory fails on several geological counts. The Russian claims about the Donestk Ukraine deposits are faulty geology. The fractured crytalline basement rock happens to have overthrust underlying traditional marine shale source rock. The trace oil recovered from the Swedish experiment came from the drilling mud. All oil comes from catagenesis, usually of marine kerogen from algae and cyanobacteria, rarely from peat turning to coal. Some of the deepwater fields west of Norway are if this latter type.
Rud –
With regard to Gold’s result with the Siljan (Sweden) experiment, according to the Deep Hot Biosphere book the oil recovered was, while very far from commercial quantities, much larger than the “trace” amounts as you and others have described it. (To me, trace implies tiny tiny fractions – like an amount I wouldn’t worry about in a glass of drinking water.) In one pump-up, they recovered 12 tons of quite normal crude oil. In addition to the crude, they pumped up the famous brown crud – the fine-grained magnetite in the amount of 15 tons which Gold felt was reduced from an oxide by microbes. It was principally this paste that clogged and shut down further efforts. (I believe you are a farmer so may have encountered a similar situation digging self-filling fence-post holes!) And there was a second control bore which used water as the “principal drilling fluid”. We could use more details.
Nick,
Oxygen is also abundant on Titan, which after all is encased in H2O ice and harbors liquid water at depth.
We are not pumping dinosaurs into our gas tanks. There is no evidence which shows that there has ever been that much organic material which would be available for transformation into coal and other petrochemical things. Any suggestion that hydrocarbons are only found through decayed organic, and I do mean (formerly living), matter from the surface of the earth is ridiculous.
Sadly, we all know that being rediculous has never stopped anyone from believing anything. The climate change scare is proof of this.
It has been known for a while that submarines doing research while exploring the “Juan de La Fuca plate”, off of the Pacific Northwest, discovered “Abiotic” hydrocarbons in water samples taken from “black smokers” and the hot water vents deep in the Pacific ocean.
Even the biblcal story of Sodom and Gommorah in Gen 19:24, discusses “fire and brimstone” (raining) on those cities.
Divine intervention or volcanism, whichever is preferable to the reader, would suggest that if these flammable things can fall from the sky on the earth, they can fall from the sky in other places and possibly on other planets as well.
The light spectre from outgassing comets, and from stars and within interstellar space suggests that these hydrocarbon materials are present in some form in many other places as well.
(from the primer linked below)
“Methane has been detected on:
Jupiter, Mars, Saturn (and its moons Iapetus, Titan, Enceladus), Neptune (Triton), Uranus (Ariel, Miranda, Oberon, Titania, Umbriel), Pluto, Comet Halley, Comet Hyakutake and cosmic dust, Nebulae and Interstellar gas.”
This would exclude the idea that petroleum exists only by a process which is organic and of a terrestrial Earthly origin.
A primer about abiotic hydrocarbons can be read here: http://origeminorganicadopetroleo.blogspot.com/2011/02/normal-0-21-false-false-false-pt-br-x.html.
Methane has also been detected on Mercury, Venus and the Moon.
I don’t see the difficulty in methane formation of higher alkanes in a deep geological environment. If the methane is to any extent in a liquid state at high pressure, the pressure-driven thermodynamics of the situation could favor its concatenation into longer chains (to increase density, releasing pressure-volume work energy) while releasing hydrogen that would be soluble in the surrounding medium and which would diffuse away. Meanwhile, on its way up through the rock layers, it would reduce oxygen (water), nitrogen (ammonia), and sulfur (hydrogen sulfide) and bring them to the surface. Ref. Vladimir Larin’s work.
A worthwhile read for the topic of abiotic/abiotic methane: “The Spark of Life” by Christopher Wills and Jeffrey Bada
Any thoughts on the Yamal Peninsula in Russia? Use GoogleEarth yo zoom in.
Rud Istvan
There is no credible abiogenic methane on Earth given its geologic history
================
Yes there is – but you have to look.
“Ryan S:
There is only one way, currently known, for generating oil and that is Thermogenic generation.”
===============
” I could go into excruciating detail of all the different types of Kerogen, their formation, and thermal maturation, but I’ll only do it if you are truly interested.”
I am truly interested in your explanation for the “Kerogen rich rock” (capital K for important) called Comet Haley, comprised of 1/3 “kerogen” (better known as “oil shale”). That’s equivalent to around 500 years of OPEC output on a tiny lifeless pebble, btw.
Can you explain the formation of that “kerogen”?
http://en.wikipedia.org/wiki/Oil_shale#Extraterrestrial_oil_shale
I am not against the idea of abiotic methane, given, as discussed by many above, the evidence from various moons in our solar system. However, two comments:
1) I’ve read quite a bit of this but do not see where it is ruled out that the hydrates found in this study are biotic in origin rather than abiotic.
2) As other commenters above have said, those of us involved in commercial exploration and production of hydrocarbons base our approach on 5 elements to an oil or gas field before drilling: these are:
a) an organic-rich source rock (a layer of sediment that includes algal, planktonic or plant material;
b) the thermal maturation of such material, and its migration to a useful “reservoir” rock with porosity and permeability, (in the case of fraccing plays the porosity and permeability are created by fracturing);
c) the existence of such “reservoir” rock;
d) a structure (either tectonic or stratigraphic) in which the migrated oil or gas accumulates;
e) a seal which retains the hydrocarbons in such structure.
Those of us who have had wells drilled on such prospective areas, and have made discoveries of oil or gas are quite happy that this approach is the way forward to finding oil and gas. By considering the probabilities of these 5 factors, our exploration efforts are kept realisitc. That way, we make enough discoveries to keep the companies we work for as going concerns. And we keep all of you supplied with hydrocarbons to power your cars, heat your homes etc..
This is not to refute the possibility of abiotic hydrocarbons. This is just to emphasise that this approach (assuming that heated organic material is one of 5 requisites for a good drill prospect) has been succesful
in the oil and gas industry. By the way, my employer also has interests in Russia, where the exact same approach is taken.