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It looks like we might be witnessing the dramatic death of an ice cap in the northern stretches of Russia.
Between 1985 and 2013, Landsat satellite imagery showed that the Vavilov Ice Cap was very slowly drifting at a seemingly stable pace. Then, around 2013, the action really started to heat up and glaciologists began to notice the glacier sliding dozens of times faster than normal. According to the NASA Earth Observatory blog, the glacier is sliding the length of a train carriage every single day.
This surge of ice loss is especially unusual because the Vavilov Ice Cap is a cold-based glacier in a polar "desert" with very little precipitation. This means it should be relatively immune to the pressures that burden other glaciers, such as melting from beneath by warming seawater, as it is frozen stuck to the glacier bed.
You can expect to see glaciers shift size and shape through the natural process of calving. However, what the researchers are seeing here is unprecedented. If the ice cap is shifting at this kind of rate, the researchers suspect that water must have made its way up and under the land-based part of the glacier, causing it to become more susceptible to warming global temperatures.
“The fact that an apparently stable, cold-based glacier suddenly went from moving 20 meters [65 feet] per year to 20 meters per day was extremely unusual, perhaps unprecedented,” Michael Willis, a University of Colorado Boulder glaciologist, told NASA Earth Observatory.
“The numbers here are simply nuts. Before this happened, as far as I knew, cold-based glaciers simply didn’t do that… couldn’t do that.”
The Vavilov Ice Cap was the subject of a study by Willis and a team of researchers at Colorado Boulder just last year, which further highlighted the scale of the glacier’s demise. In the three decades prior to 2013, the Vavilov Ice Cap melted away by a total of a few meters. Then, between 2015 and 2016, the ice cap thinned by about 100 meters (328 feet), around 0.3 meters (0.9 feet) per day, creating enough water to cover Manhattan with about 75 meters (246 feet) of water.
As the researchers note, the plight of Vavilov highlights that cold glaciers in other polar regions, especially those along Antarctica and Greenland, could be more vulnerable to climate change than climate models have previously predicted.
“This event has forced us to rethink how cold-based glaciers work,” added Willis. “It may be that they can respond more quickly to warming climate or changes at their bases than we have thought.”
