Yashashree Malpathak
www.mediaeyenews.com
In an unusually hot climate, when the temperature was around 90 Degree Fahrenheit, a mystery crater was first reported in 2014 on the Yamal Peninsula, around 26 miles (42km) from the Bovanenkovo gas field. Pilots flying over the Yamal Peninsula saw a massive crater in the earth that formed out of nowhere, in the same area where Greg Fiske and his colleague Sue Natali from the Woodwell Climate Research Center were working. Since then, other similar craters have been discovered in two regions: the Yamal and Gyda peninsulas. They are a part of Russia's Siberian tundra, a vast expanse of land, marked by a layer of permanently frozen soil just beneath the surface.
Many researchers examined the crater and made models of it. However, each new crater has its distinct characteristics. Scientists have discovered that a mound known as a 'Pingo' forms first, then quickly grows, reaching several meters in height. Large chunks of earth and ice can be thrown hundreds of meters away from the epicenter when the mound erupts. It is faced with a massive force caused by extremely high pressure. The reasons for this pressure, however, are unknown.
The landscape has 17 confirmed craters, but only seven have been documented in scientific studies. It has been found so far that the explosions are caused by gas, most likely methane, accumulating in isolated pockets over the tundra. The pressure builds up quickly — the hills preceding each explosion swell in three to five years — and the bubble finally bursts when the strain becomes too severe. The edge of the hole eventually melts and expands in the perimeter as the bottom fills with water months to years after the explosion—making it appear like a lake that blends into the many lakes that are found in the region.
Scientists are still attempting to find the cause of the explosions, but it's most likely a type of cryovolcanism involving ice and mud eruptions. It is a region of thick ice known as tabular ice and also of areas of ground within the frozen permafrost called ‘Cryopegs’. Although it is bordered by permafrost, the ground is not frozen. The notion behind how these craters are formed is that deep deposits of gas find their way to the unfrozen pocket of ‘Cryopeg’ or ‘Talik’, and as the pressure builds up, the ground rises with rising pressure, and the explosion occurs.
Craters form in permafrost's topmost horizons. Permafrost is extremely susceptible to climate change, and its development is linked to climate-related global cooling periods. The craters can be up to 70 meters (230 feet) in diameter and more than 50 meters (164 feet) deep. After a crater explosion in 2017, local reindeer herders reported seeing flames and smoke, but because of their remote location, sightings of these explosions are extremely unusual.
Researchers have since investigated the area around each hole, inspected the blown fragments to see what kind of material they revealed, and even dived inside the craters to investigate the interior. The craters are being viewed using satellite data. A change detection map is constructed, which is an automated means of detecting pixels that have changed in some way on the peninsula. Land changes leading up to each explosion have also been depicted using satellite imagery compiled from the locations before the explosion. High-resolution imagery is used to examine each of these pixels and determine whether or not it is a crater, then classify it accordingly.
Warming temperatures are believed to play a role, at least in part, by making the earth unstable, allowing for these explosions. According to Sue Natali, it's a startling indicator of the Arctic's condition because the physical structure of the ground is most likely changing nowhere else as a result of climate change. How new these craters are and why they’re caused, the impact of methane escaping from the craters, its relation to global climate, and the risk to people, gas, and oil infrastructure around these sites are all unclear.
