Retrogressive thaw slump
The largest RTS in the world is in Siberia—the Batagaika Crater, also called a "megaslump"—is one kilometre long and 100 metres (330 ft) deep and it grows a 100 feet (30 m) annually.
[7] Permafrost dates back hundreds of thousands of years; thermokarst and its features—such as retrogressive thaw slumps—which are slope failures, have been initiated by terrain disturbance associated with clear-cutting forests, the construction of seismic lines and roads.
[14] RTS morphology comprises a vertical headwall, an inclined headscarp, a floor filled with flow deposits, and a lobe that conveys thawed sediments downslope.
"[35] Recent landslides into Lake Tiktalik in the Western Arctic have created large thaw slumps—measuring several hundred feet in both width and depth—indicating the rapid degradation of permafrost.
According to New York Times, these thaw slumps "are the most dramatic evidence of a phenomenon that could turn the local Inuvialuit into Canada’s first climate refugees."
A 2022 inventory identified 875 widely distributed RTSs,[37] along the highly developed corridor with significant infrastructures, including the Qinghai–Tibet Railway and the Qinghai–Tibet Highway, "as well as power and communication towers".
[26] It is in central Yakutia in the East Siberian taiga in Verkhoyansky District of the Sakha Republic that the world's largest retrogressive thaw slump, the Batagaika Crater, is located.
[26] Because of its massive size—it is 1 km (0.62 mi) long and 100 metres (330 ft) deep and growing annually[39]—the Batagaika Crater has been called a "megaslump"—a large retrogressive thaw slump.
[27] The bottom layer of permafrost sediment has been estimated to be "at least six hundred and fifty thousand years old",[attribution needed] based on luminescence dating of drill bores extracted by Murton and his team.
[26] Murton said that this means that the permafrost "survived the previous interglacial period, which began some hundred and thirty thousand years ago ...
The scientists thawed the nematodes; it revived and began moving and eating, making it one of the oldest living multicellular animals on Earth.
[41][42] There is a pingo retrogressive thaw slump in the Akkol Valley, one of three U-shaped valleys—including Taldura and Karaoyuk—that comprise the Altai Mountains South Chuyskiy Range in Mongolia.
[43] As the climate warms, "terrain-altering thermokarst" retrogressive thaw slumps represent the "most rapid and dramatic changes" in permafrost regions.
[attribution needed][44] Permafrost in the Northern Hemisphere, which covered approximately 23,000,000 square kilometres (8,900,000 sq mi; 2.3×109 ha; 5.7×109 acres), representing 24% of the terrestrial area, as of 1997[45] is vulnerable to climate warming.
[check quotation syntax][3] Retrogressive thaw slumps threaten Canada's infrastructure and contributes to mercury contamination in the water.
[48] in the western Canadian Arctic, Inuvialuit residents of the hamlet of Sachs Harbour, Banks Island reported seeing an increase in the number of slumps, which had affected "travel for traditional hunting and fishing activities.
"[attribution needed][49][5] "Advances in remote sensing techniques, and their application in a broad suite of change detection studies, indicate recent increases in the rates and magnitude of thermokarst including retrogressive thaw slumping, lake expansion and the transformation of frozen peatlands to collapsed wetlands.
"[attribution needed][2] In Canada, computerized alert systems are being installed to monitor humidity, temperature and other factors at RTSs that threaten infrastructure, such as the Alaska Highway.
"[attribution needed][3] According to a 1990 study, woodchip insulation on ice-rich slopes were used to slow down slumping along the "pipeline route from Norman Wells, NWT, to Zama, Alberta.
