Avalanche
Large powder avalanches can quickly and easily reach speeds of 80mph, and don’t last for very long, so the fact that a NASA satellite managed to capture an image of one in action has been described as ‘a stroke of luck’.
On April 17, 1996, satellite Landsat-5 was passing over the Karakoram Mountains, Pakistan, at the exact moment an avalanche was occurring on Kanjut Sar (peak 7760 metres, 25,460 feet). The image taken had remained undiscovered for more than 20 years until Jakob Steiner, a geoscientist at Utrecht University in the Netherlands, recently came across it. On June 16, 2017, he tweeted:
“[T]hat moment when a powder avalanche hits the glacier surface exactly at the time of a Landsat overpass.”
Jakob was scouring the images while studying the Khurdopin Glacier, which has a history of surging, to track a newer, faster surge that began in October 2016 and could result in dangerous floods downstream.
Adam Voiland, a writer for NASA Earth Obeservatory, had further details.
“The source of the avalanche appears to be a slope at roughly 6,500 metres (21,000 feet) elevation. As the avalanche gathered force, snow swept into a valley and tumbled nearly 750 meters (2,500 feet) onto Khurdopin Glacier.”
The Karakoram is a large mountain range spanning 311 miles along the borders of Pakistan, India and China, and extending as far North as Afghanistan and Tajikistan. It is the most glaciated area of the world outside of the polar regions and can count the worlds second highest mountain, K2, as one of its peaks. Kanjut Sar is the 11th highest mountain in Pakistan, the 26th highest in the world and is well known for its avalanches.
Who knows if we’ll see images like this in the future. NASAs funding is being cut and they are being instructed to focus more on reaching Mars than on Earth Science. NASAs satellites currently cover over 200 million square miles of the Earth’s surface.
