You can help expand this article with text translated from the corresponding article in Russian. (January 2021)Click [show] for important translation instructions.
|
A gas emissions crater or GEC is a crater that is left by an explosion that is believed to be caused by an overheated buildup of gas stuck below a layer of permafrost. [1] The gas is methane (also known as "natural gas") and is generally believed by experts to have sept up from large underground reserves toward the Earth's surface "through some kind of geological fault," [1] getting trapped when they reach the bottom of the permafrost. [1] [2] [3] First known to have occurred in 2013, they are occurring solely in Siberia, where there are large stores of natural gas below a melting surface layer of permafrost. [1] They are believed to be a byproduct of global climate change, since the warming of Siberia's climate weakens the permafrost enough to allow a sub-surface methane buildup to cause an outburst. [1] [4] The release of this previously trapped methane into the atmosphere is also likely to increase the speed of global climate change. [1]
Gas emission craters were first spotted in 2013; [5] later satellite analysis has indicated that it was formed sometime between October 9 and November 1, 2013. Most famously, the discovery of the Yamal crater in 2014 quickly drew the attention of world media. [6] As of 2020, there were 17 known gas emissions craters, all of which are in the circumpolar regions of Western Siberia, on either the Yamal Peninsula or the neighboring Gydan Peninsula, which both sit atop large underground methane reserves. [4] They are variously located on land as well as at the bottom of rivers and lakes. Soon after their discovery, the term "gas emissions crater" was proposed and subsequently accepted by the scientific community.
Initially, with the sudden global fame of the Yamal crater , various hypotheses of its origin were put forward, including military tests, meteorite impact, UFOs, or the collapse of an underground gas facility. [7] [8] Later, in September 2018, a group of researchers from Moscow State University published an article in the journal Scientific Reports that claimed that the Yamal crater was the first cryovolcano discovered on Earth. [9]
Subsequently, however, in the course of scientific research, the scientific community has come to the general conclusion that the crater was formed as a result of the so-called gas release – an underground explosion of methane hydrates which ejects into the air all the rock and soil above it (along with releasing the methane itself). [10] [1] [2] [3] More specifically, their formation most likely occurs under the influence of fluid-dynamic processes in permafrost, which lead to the appearance of zones of accumulation of free natural gas near the surface. In this case, when the reservoir pressure of the accumulated gas fluids exceeds the pressure of the overlying strata, an avalanche-like outburst of gas-saturated rocks may occur. While thawing can promote methane release it has also been suggested that surface ice-melt water can migrate downward propelled by osmotic pressure associated to the concentration difference with a cryopeg, a lens of high-salinity water below, working as a mechanism for the accumulation of overpressure driving explosions. [11] [12]
Siberia is an extensive geographical region comprising all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has formed a part of the sovereign territory of Russia and its predecessor states since the centuries-long conquest of Siberia, which began with the fall of the Khanate of Sibir in the late 16th century and concluded with the annexation of Chukotka in 1778. Siberia is vast and sparsely populated, covering an area of over 13.1 million square kilometres (5,100,000 sq mi), but home to roughly a quarter of Russia's population. Novosibirsk, Krasnoyarsk, and Omsk are the largest cities in the area.
The Tunguska event was a large explosion of between 3 and 50 megatons that occurred near the Podkamennaya Tunguska River in Yeniseysk Governorate, Russia, on the morning of 30 June 1908. The explosion over the sparsely populated East Siberian taiga flattened an estimated 80 million trees over an area of 2,150 km2 (830 sq mi) of forest, and eyewitness accounts suggest up to three people may have died. The explosion is generally attributed to a meteor air burst, the atmospheric explosion of a stony asteroid about 50–60 metres wide. The asteroid approached from the east-south-east, probably with a relatively high speed of about 27 km/s (60,000 mph). Though the incident is classified as an impact event, the object is thought to have exploded at an altitude of 5 to 10 kilometres rather than hitting the Earth's surface, leaving no impact crater.
Methane clathrate (CH4·5.75H2O) or (4CH4·23H2O), 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 the Earth (approx. 1100m below the sea level). Methane hydrate is formed when hydrogen-bonded water and methane gas come into contact at high pressures and low temperatures in oceans.
Permafrost is soil or underwater sediment which continuously remains below 0 °C (32 °F) for two years or more: the oldest permafrost had been continuously frozen for around 700,000 years. Whilst the shallowest permafrost has a vertical extent of below a meter (3 ft), the deepest is greater than 1,500 m (4,900 ft). Similarly, the area of individual permafrost zones may be limited to narrow mountain summits or extend across vast Arctic regions. The ground beneath glaciers and ice sheets is not usually defined as permafrost, so on land, permafrost is generally located beneath a so-called active layer of soil which freezes and thaws depending on the season.
The Yamal Peninsula is located in the Yamalo-Nenets Autonomous Okrug of northwest Siberia, Russia. It extends roughly 700 km (435 mi) and is bordered principally by the Kara Sea, Baydaratskaya Bay on the west, and by the Gulf of Ob on the east. At the northern end of this peninsula lie the Malygina Strait and, beyond it, Bely Island. Across the river lies the Gyda Peninsula. In the language of its indigenous inhabitants, the Nenets, "Yamal" means "End of the Land".
Thermokarst is a type of terrain characterised by very irregular surfaces of marshy hollows and small hummocks formed when ice-rich permafrost thaws. The land surface type occurs in Arctic areas, and on a smaller scale in mountainous areas such as the Himalayas and the Swiss Alps.
Vladimir Afanasyevich Obruchev was a Russian and Soviet geologist who specialized in the study of Siberia and Central Asia. He was also one of the first Russian science fiction authors.
The clathrate gun hypothesis is a proposed explanation for the periods of rapid warming during the Quaternary. The hypothesis is that changes in fluxes in upper intermediate waters in the ocean caused temperature fluctuations that alternately accumulated and occasionally released methane clathrate on upper continental slopes. This would have had an immediate impact on the global temperature, as methane is a much more powerful greenhouse gas than carbon dioxide. Despite its atmospheric lifetime of around 12 years, methane's global warming potential is 72 times greater than that of carbon dioxide over 20 years, and 25 times over 100 years. It is further proposed that these warming events caused the Bond Cycles and individual interstadial events, such as the Dansgaard–Oeschger interstadials.
The Gyda Peninsula is a geographical feature of the Siberian coast in the Kara Sea. It takes its name from the river Gyda, that flows on the peninsula. It is roughly 400 km long and 360 km wide. This wide peninsula lies between the estuaries of the Ob and Yenisei Rivers. The southwestern corner of the peninsula is limited by the Taz Estuary, and across the river lies the Yamal Peninsula. The climate in the whole area is arctic and harsh.
Methane is a chemical compound with the chemical formula CH4. It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The abundance of methane on Earth makes it an economically attractive fuel, although capturing and storing it is difficult because it is a gas at standard temperature and pressure. In the Earth's atmosphere methane is transparent to visible light but absorbs infrared radiation, acting as a greenhouse gas. Methane is an organic compound, and among the simplest of organic compounds. Methane is also a hydrocarbon.
Arctic methane emissions contribute to a rise in methane concentrations in the atmosphere. Whilst the Arctic region is one of many natural sources of the greenhouse gas methane, there is nowadays also a human component to this due to the effects of climate change. In the Arctic, the main human-influenced sources of methane are thawing permafrost, Arctic sea ice melting, clathrate breakdown and Greenland ice sheet melting. This methane release results in a positive climate change feedback, as methane is a powerful greenhouse gas. When permafrost thaws due to global warming, large amounts of organic material can become available for methanogenesis and may therefore be released as methane.
Katey M. Walter Anthony is an Alaskan aquatic ecologist and biogeochemist researching carbon and nutrient cycling between terrestrial and aquatic systems, and the cryosphere and atmosphere.
Sergey Aphanasievich Zimov is a Russian geophysicist who specialises in arctic and subarctic ecology. He is the Director of Northeast Scientific Station, a senior research fellow of the Pacific Institute for Geography, and one of the founders of Pleistocene Park. He is best known for his work in advocating the theory that human overhunting of large herbivores during the Pleistocene caused Siberia's grassland-steppe ecosystem to disappear and for raising awareness as to the important roles permafrost and thermokarst lakes play in the global carbon cycle.
Atmospheric methane is the methane present in Earth's atmosphere. The concentration of atmospheric methane is increasing due to methane emissions, and is causing climate change. Methane is one of the most potent greenhouse gases. Methane's radiative forcing (RF) of climate is direct, and it is the second largest contributor to human-caused climate forcing in the historical period. Methane is a major source of water vapour in the stratosphere through oxidation; and water vapour adds about 15% to methane's radiative forcing effect. The global warming potential (GWP) for methane is about 84 in terms of its impact over a 20-year timeframe, and 28 in terms of its impact over a 100-year timeframe.
A methane chimney or gas chimney is a rising column of natural gas, mainly methane, within a water or sediment column. The contrast in physical properties between the gas phase and the surrounding water makes such chimneys visible in oceanographic and geophysical data. In some cases, gas bubbles released at the seafloor may dissolve before they reach the ocean surface, but the increased hydrocarbon concentration may still be measured by chemical oceanographic techniques.
Pleistocene Park is a nature reserve on the Kolyma River south of Chersky in the Sakha Republic, Russia, in northeastern Siberia, where an attempt is being made to re-create the northern subarctic steppe grassland ecosystem that flourished in the area during the last glacial period.
The permafrost carbon cycle or Arctic carbon cycle is a sub-cycle of the larger global carbon cycle. Permafrost is defined as subsurface material that remains below 0o C for at least two consecutive years. Because permafrost soils remain frozen for long periods of time, they store large amounts of carbon and other nutrients within their frozen framework during that time. Permafrost represents a large carbon reservoir, one which was often neglected in the initial research determining global terrestrial carbon reservoirs. Since the start of the 2000s, however, far more attention has been paid to the subject, with an enormous growth both in general attention and in the scientific research output.
The Patomskiy crater or Patom crater, also known as Конус Колпакова, Konus Kolpakova "Kolpakov cone") is a peculiar rock formation located in the Bodaibo District of the Irkutsk region of southeastern Siberia, 360 kilometres (220 mi) from the district center Bodaibo. It is a large mound made of shattered limestone blocks on the slopes of the Patom Highlands in an area of dense taiga. Its base diameter is about 160 metres (520 ft) and its height about 40 metres (130 ft); the cone's crown is ring-shaped, and in its center there is a smaller mound with a height of about 12 metres (39 ft). The volume of the crater is estimated as 230,000–250,000 cubic metres (8,100,000–8,800,000 cu ft), with a weight of about one million tons.
The West Siberian taiga ecoregion covers the West Siberian Plain in Russia, from the Ural Mountains in the west to the Yenisei River in the east, and roughly from 56° N to 66° N latitude. It is a vast, flat lowland region of boreal forests (taiga), and wetlands, covering an area about 1,800 km west–east, by 1,000 km north–south.
Increasing methane emissions are a major contributor to the rising concentration of greenhouse gases in Earth's atmosphere, and are responsible for up to one-third of near-term global heating. During 2019, about 60% of methane released globally was from human activities, while natural sources contributed about 40%. Reducing methane emissions by capturing and utilizing the gas can produce simultaneous environmental and economic benefits.