This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: Florida gets a lot of attention for its sinkholes, especially when they swallow cars and entire houses. But its sinkhole risk has nothing on Alaska's.
Much of Alaska's soil is permafrost—ground that remains below 32 degrees Fahrenheit (0 degrees Celsius) for at least two consecutive years. It is often rich with ice, but when that ice melts, the ground can collapse. As temperatures rise, that's happening more often across the Arctic.
The consequences are the same as in Florida: substantial property damage as the land beneath buildings, roads and pipes sinks. Yet despite the high potential for damage, up-to-date maps of permafrost thaw that could help Arctic residents and community leaders prepare are often rare. To fill the gap, our team, led by hydrologists and data scientists, created an interactive website to track permafrost thaw in near-real time across the Arctic, using a unique quality of the Arctic's version of the sinkhole.
There is no way to directly measure permafrost without digging into it, but there are signs to watch for. When ice-rich permafrost thaws, the ground surface subsides, creating what are known as thermokarst ponds—depressions that fill with water. Much of the Arctic has become dotted with ponds and lakes that formed this way as temperatures there rise at two to three times the global average.
Looking at satellite imagery, it's easy to spot these lakes. Watching how they change over time can then provide clues to how the permafrost is changing below. Sometimes, the same process that started the sinkhole can form new stream channels that drain the lake, leaving a circular basin of bare ground behind.
A lake that is several hundred meters long might have taken a millennium to form, yet permafrost thaw triggered by one unusually warm summer can completely drain the same lake in just a few hours. When a lake abruptly disappears, that's a strong indicator that the ice-rich permafrost has thawed. Disappearing lakes also provide a way to monitor permafrost over wide areas and track where thawing is most active.
Extract — continue reading at the source.
