Nils Thomas discovered "sinkhole" in the middle of Finnmarksvidda. Scientists have long warned against this, and now it happened.

Concern about permafrost thaw and possible impacts to underground water and wastewater lines.

Russian scientists in the Arctic Ocean said they have discovered the most powerful methane gas fountain ever recorded, highlighting the danger of this greenhouse gas accelerating climate change or causing an oil or gas spill as it erupts from thawing permafrost.

Usually one of the most full flowing in Russia, the river tends to drop the level twice a year - but not by a catastrophic 2-2.5 meters as this year.

In early October 2013, local fishers Eli Nukapigak and Edward Nukapigak Jr. alerted wildlife officials to the discovery of “sick fish” in their nets near Nuiqsut. The aanaakłiq had fuzzy grayish-white patches on their bodies, fins, and heads. Cottony masses almost covered the eyes of some fish. None of the fishers in the community recalled seeing this condition before.

Some 784,931 hectares of wildfires are raging on permafrost zones including the Arctic in Yakutia - officially Sakha Republic - and the Khanty-Mansi autonomous region, causing possibly irreparable damage to the tundra. Other infernos are sweeping through boreal forests which are known as the lungs of the Northern Hemisphere.

The Artic landscape is changing at an unprecedented pace: in Sweden, Alaska and elsewhere entire towns and villages, houses half sunken into the ground, risk being moved to more stable ground, as the permafrost they had been built on shifts and melts. In the Canadian north, suitable houses have become so rare that apartment prices have skyrocketed, triggering a housing crisis. All around the Arctic, homes lay abandoned, the damage too severe. Roads and other vital infrastructure are at risk, too.

The fires are now raging some 10 to 15 kilometers from the megaslump crater - a large hole in the frozen Arctic soil which highlights the dramatic speed of thawing permafrost.

The varnished wooden cross stands amid a cluster of grave markers tilted at odd angles in the cemetery, because the ground beneath them is sinking. Rising temperatures are thawing the once-frozen earth, forming pools of water that run through the graveyard.

Kettle ponds in Denali National Park contain less water this spring than in previous years, due to low snowfall and permafrost thaw. Shrubs are replacing grasses as the lakes dry.

Deteriorating conditions on the Mackenzie Valley Winter Road have prompted the Northwest Territories government to close the winter highway for the season.

The incident appears similar to an oil and gas release in 2017 blamed on thawing permafrost and hot production fluids.

Mills in the heart of Canada's timber industry have fallen quieter this winter as wildfires and infestations made worse by climate change have made vast tracts of once valuable forest into barren stands of dead trees.

The rapidly warming Arctic is no stranger to loss. Climate change is gradually claiming some of its most iconic features, from melting glaciers in Greenland to shrinking sea ice in the ocean.

A permafrost coastline is receding dramatically along Alaska's North Slope region. It could be an indicator of far more massive land losses across the Arctic.

Climate change is causing trouble on Herschel Island.

“It’s an area that I and some other colleagues have started thinking about: can you get methane forming in terrestrial environments? But it’s a very new area of science,” carbon scientist Katey Walter Anthony said.

Thawing and eroding is destroying river bank, impacting access, threatening infrastructure, and causing safety concerns.

A magnitude 6.4 earthquake rattled a remote region of Alaska's North Slope southeast of Prudhoe Bay Sunday morning. The state seismologist called it the biggest quake ever recorded in the region.

Transportation engineers moved the road to avoid a giant mass of frozen debris sliding downhill.