In 2006, scientists witnessed an astonishing sight. In barely two hours, a lake drained away into the earth. This was no puddle. The lake in question held 45 billion liters (12 billion gal) of water.
The unusual phenomenon repeats each summer in Greenland. Every year, melting snow spawns thousands of lakes. They only remain stable for a few weeks before suddenly vanishing. The thirsty culprit is a vast sheet of ice below. As soon as temperatures rise, a network of cracks opens and then swallows huge lakes at astonishing speeds.
In 2018, researchers announced that the trend had taken a worrying turn. The underground web was increasingly gulping lakes inland, even those thought to be too far away to be affected. Once again, rising temperatures are to blame. As summers get hotter, the fissures spread.
It becomes a game of dominoes. One lake’s water drains in a powerful surge and weakens the neighboring lake beds. New cracks form, and more lakes fall and destabilize their neighbors. One such chain reaction lasted five days and drained 124 lakes. Most of the water ends up in the ocean and is responsible for annually raising global sea levels by 1 millimeter (0.04 in).
From storybook snowcapped mountains to the poles, Earth’s cold spots make for an interesting experience. Ski antics and monster sightings aside, ice fields can produce things that scientists have never seen before, clues about history, and even far-reaching disasters that are born in the Arctic.
Tourists travel to remote places to witness fantastic events, while icebergs and shelves behave in ways that scientists cannot explain. But the frozen depths can also hold some of the most terrifying discoveries and disappearances in the natural world.