It's no wonder the photo went viral: The sled dogs appear to be walking on water. The story behind the June 13 image is making the rounds as well. It was taken by Danish scientist Steffen Olsen in northwest Greenland, where the dogs were traversing an ice sheet roughly 4 feet thick in order to retrieve oceanographic and weather monitoring devices. The meltwater on top was ankle deep, reports the Guardian, which spoke with another scientist with the Danish Meteorological Institute (DMI). Ruth Mottram explained the "ice here forms pretty reliably every winter," and due to its thickness, fractures tend not to form—meaning the meltwater has nowhere to go. Mottram said it was too early to fault climate change as the cause in this case, but in a tweet, Olsen said "extreme events" like this one "call for an increased predictive capacity in the Arctic."
CNN details what's different about this year's summer melt. It reports that scientists have been saying this year might be a record-setting one: 40% of Greenland saw melting when the photo was snapped on June 13. The melting traditionally runs from June to August, peaking in July, but the AP reports the DMI says it began April 30 this year, the second earliest time since the date started being recorded in 1980. Per CNN, the amount of ice already lost before the melting season really comes into force suggests scientists' prediction appears to be coming to pass. The melting can also cause a sort of snowball effect: With less white snow and ice to reflect the sun's rays, the amount of heat that's absorbed is amplified, further contributing to the melt. (Major climate talks are taking place in Germany right now.)