"Chicken Little" crowd
you are a pot stirrer
Several hundred of craters in the area. Over one hundred of them are up to one kilometer wide.
A new study in Science shows that hundreds of massive, kilometer-wide craters on the ocean floor in the Arctic were formed by substantial methane expulsions.
Even though the craters were formed some 12,000 years ago, methane is still leaking profusely from the craters. Methane is a potent greenhouse gas, and of major concern in our warming climate.
In comparison, the huge blow-out craters on land on the Siberian peninsulas Yamal and Gydan are 50-90 meters wide, but similar processes may have been involved in their formation
"The crater area was covered by a thick ice sheet during the last ice age, much as West Antarctica is today. As climate warmed, and the ice sheet collapsed, enormous amounts of methane were abruptly released. This created massive craters that are still actively seeping methane " says Karin Andreassen, first author of the study and professor at CAGE Centre for Arctic Gas Hydrate, Environment and Climate.
Today more than 600 gas flares are identified in and around these craters, releasing the greenhouse gas steadily into the water column.
"But that is nothing compared to the blow-outs of the greenhouse gas that followed the deglaciation. The amounts of methane that were released must have been quite impressive."
A few of these craters were first observed in the 90-ties. But new technology shows that the craters cover a much larger area than previously thought and provides more detailed imaging for interpretation
"We have focused on craters that are 300 meters to 1 kilometre wide, and have mapped approximately 100 craters of this size in the area. But there are also many hundred smaller ones, less than 300 meters wide that is" says Andreassen.
"Despite their infrequency, the impact of such blow-outs may still be greater than impact from slow and gradual seepage. It remains to be seen whether such abrupt and massive methane release could have reached the atmosphere. We do estimate that an area of hydrocarbon reserves twice the size of Russia was directly influenced by ice sheets during past glaciation. This means that a much larger area may have had similar abrupt gas releases in the overlapping time period " says Andreassen
Another fact to consider is that there are reserves of hydrocarbons beneath the ice overburden of West Antarctica and Greenland ice sheets today.
K. Andreassen el al., "Massive blow-out craters formed by hydrate-controlled methane expulsion from the Arctic seafloor," Science Vol. 356, Issue 6341, pp. 948-953 (2017).
Warning of methane blasts in Kara Sea adjacent to Yamal craters caused by gas eruptions associated with melting permafrost due to global warming.
Huge attention has focused on the mysterious large holes that have suddenly appeared in the Siberian Arctic recently, and now there is evidence of a similar process underwater in southern areas of the Kara Sea.
Large mounds - described as pingos - have been identified on the seabed off the Yamal Peninsula, and their formation is seen as due to the thawing of subsea permafrost, causing a 'high accumulation' of methane gas.
These mounds 'are leaking methane' and their 'blowout potential' poses a significant 'geohazard' to energy exploration in Arctic waters, according to new research by scientists at Centre for Arctic Gas Hydrate, Environment and Climate (CAGE) in Norway, supported by the Federal Subsoil Resources Management Agency of Russia.
For example, in a little-reported incident 20 years ago, during 'geotechnological drilling' by Russian vessel Bavenit in the Pechora Sea, a pingo gas deposit was opened, threatening the ship's safety with a sudden methane release.
Dr Pavel Serov, lead author of the research which is published in the Journal of Geophysical Research, said: 'Pingos are intensively discussed in the scientific community especially in the context of global climate warming scenarios. They may be the step before the methane blows out.' The researchers focused on 'two subsea pingos that were identified offshore (of) the very same area of the mysterious Yamal peninsula craters', reported the CAGE website.
The Norwegian study 'shows how important methane accumulation is for the formation of subsea pingos'. These structures are 'now found strewn on the ocean floor in the Arctic shallow seas', according to the research by CAGE, part of UiT The Arctic University of Norway. 'The study area lies in the shallow South Kara Sea, at approximately 40-metre water depth.'
The underwater mounds were between 70 metres and 1,000 metres in diameter, and had been spotted originally on a seismic study of the area. They rise between five and nine metres above the surrounding sea floor. In overall size they are considerably larger than those found on land in Yamal.
Dr Serov said: 'Our question was: Are these mounds submerged terrestrial pingos? Or are they something different forming under marine conditions? One of the South Kara Sea pingos was leaking a lot of methane but where was the methane coming from?'
Initially it was thought the undersea pingos were 'relics of the Ice Age', but the groundbreaking new research indicates the reverse, indicated CAGE director Professor Jurgen Mienert, a co-author of the paper. 'The CAGE study shows these newly discovered subsea pingos may be quite recent.'
Crucially, 'gas leakage from one of the ocean floor pingos offshore (of) Siberia shows a specific chemical signature that indicates modern generation of methane', state the researchers. 'We suggest that the mound formed more recently, moving material physically upwards.' Likewise the processes leading to methane eruptions on the neighbouring peninsula are seen as very recent.
Location of Pingo-like Features (PLF)
The researchers warned: 'For petroleum companies these areas may pose a geohazard. Drilling a hole into one of these subsea pingos, can be not only expensive but also catastrophic. During a geotechnical drilling in the close by Pechora Sea, an industry vessel unknowingly drilled a hole into one of these mounds. It triggered a massive release of gas that almost sunk the vessel.'
This is believed to refer to an incident in 1995 involving the Bavenit, west of Vaygach Island in the Pechora Sea. Dr Serov stated: 'We don't know if the methane expelled from the subsea pingos reaches the atmosphere. But it is crucial that we observe and understand these processes better, especially in shallow areas, where the distance between the ocean floor and the atmosphere is short.'
Scientists have located two fresh craters formed on Yamal peninsula this year, with the latest exploding on 28 June with the eruption picked up by new seismic sensors specifically designed to monitor such events, The Siberian Times can disclose.
First pictures of the large craters - or funnels as experts call them - are shown here, and add to four other big holes found in recent years and examined by experts, plus dozens of tiny ones spotted by satellite.
The formation of both craters involved an explosion followed by fire, evidently signs of the eruption of methane gas pockets under the Yamal surface.
Deputy director of the Oil and Gas Research Institute, Moscow, Professor Vasily Bogoyavlensky said: 'We heard the news (about the new crater) from people in Seyakha village who saw a flame of fire and then a rising pillar of smoke.'
Reindeer herder Yakov Vengo has a camp near there. His observation:'It happened some 35 to 40 kilometres north-west of Seyakha,' ... 'There was a hill not far from the camp, and it exploded. 'There were fire, smoke and huge chunks of soil 'flying out' of the epicentre. ...'The hill has vanished'
Helicopter reconnaissance of the site shows a crater appearing in a river, so it assumed the 'hill' was beside or abutting the river.
The crater is some 30-35 kilometres is around 100 km of Russia's new state-of-the-art Arctic port of Sabetta. It is in an area of crater-shaped lakes.
A mound of land along edges of the funnel confirms the fact of the explosion, Alexandr Sokolov said.'This plot of land was absolutely flat just two years ago. A year ago in 2016 it bulged and we could see that soil has cracked there'
Reindeer herders in the area of Seyakh, a village on the eastern coast of the Yamal Peninsula in the morning of June 28th reported the incident to the local authorities. They say that they from the distance saw flaring flames and a column of smoke from the area, TASS reports.
It is not the first explosion of its kind. Over the last years, several major methane blasts have occured in the gas-rich peninsula. In 2014, a major sinkhole was discovered not far from Bovanenkovo, the area which houses one of Russia’s biggest natural gas fields. That has a diameter of up to 60 meters.
There are at least ten known sinkholes in the Yamal Peninsula, as well as about 250 lakes and numerous offshore structures which indicate similar phenomena, Interfax reports.
Video - The video shows Dr Anton Sinitasky, director of the Arctic research Centre in Yamalo-Nenets region, in a small boat measuring gas - previously trapped in the frozen permafrost ground - which continues to leak from under the murky waters.
The scientist said: 'I can confirm that there was really a fire burning over the Seyakha crater. We need to rely on the words of eyewitnesses. It lasted for one or one-and-a-half hours. 'When the power of gas jet began to decrease, the burning stopped. 'But the methane continues to leak from the crater, so we have been able to take samples.'
The Seyakha eruption is the most recent of a series of crater formations recently noticed in northern Siberia. It was the only one witnessed at close hand by humans. Some 700 sites in the region are reported to be vulnerable to eruptions.
The phenomenon is seen as highlighting the release of greenhouses gases due to thawing permafrost which under relatively recent global warming capped the methane beneath the surface.
A key concern is the impact of such eruptions on industrial facilities including pipelines in the Yamal region, one of the world's largest natural gas supply locations.
'We have gathered some charred sand and grass from Seyakha, but actually no analysis is needed to confirm what is obvious: there definitely was burning. - Video
Large thaw slump on the Peel Plateau, NWT, Canada. The slump is almost 1 km wide and has displaced over 7 million cubic metres of materials over the past two decades.
... These features are becoming very large and they’ve grown particularly rapidly over the last 20 years driven by climate change, Kokelj said.
Some of these thaw slumps in the Mackenzie Delta region occupy an area of 20 to 30 hectares and they’ve displaced millions of cubic metres of materials, Kokelj said.
“And we have good evidence that this is not something that has been common in the last 100 or 1,000 years,” he said.
dohboi wrote:we predict a 72% reduction in the current periglacial climate realm by 2050...
As of now, there are some 20 known and studied craters.
In 2020, researchers found and surveyed the latest crater, dubbed C17, about 25 meters in diameter.
...
"Over the years, we've gained a lot of experience with surveillance drones, yet this 'underground aerial survey' of the C17 crater was the most difficult task I had ever faced, having to lie down on the edge of a 10-story deep crater and dangle my arms to control the drone. Three times we got close to losing it, but succeeded in getting the data for the 3-D model," Igor Bogoyavlensky, the drone pilot, says.
Keith_McClary wrote:3-D model shows off the insides of a giant permafrost craterAs of now, there are some 20 known and studied craters.
In 2020, researchers found and surveyed the latest crater, dubbed C17, about 25 meters in diameter.
...
"Over the years, we've gained a lot of experience with surveillance drones, yet this 'underground aerial survey' of the C17 crater was the most difficult task I had ever faced, having to lie down on the edge of a 10-story deep crater and dangle my arms to control the drone. Three times we got close to losing it, but succeeded in getting the data for the 3-D model," Igor Bogoyavlensky, the drone pilot, says.
Alfred Tennyson wrote:We are not now that strength which in old days
Moved earth and heaven, that which we are, we are;
One equal temper of heroic hearts,
Made weak by time and fate, but strong in will
To strive, to seek, to find, and not to yield.
Alfred Tennyson wrote:We are not now that strength which in old days
Moved earth and heaven, that which we are, we are;
One equal temper of heroic hearts,
Made weak by time and fate, but strong in will
To strive, to seek, to find, and not to yield.
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