In Canada, scientists recently found an ice wedge that survived Earth’s last major warming cycle 120,000 years ago, suggesting that even extreme climate change may not wipe out all of the planet’s frozen matter. But what exactly is an ice wedge?
During the long Arctic winter, frozen soil on the tundra can crack from the extreme cold. In the spring, water from melting snow fills the cracks and then freezes again because of the surrounding permafrost. The ice narrows and tapers to a point, forming the appearance of an underground icicle, or ice wedge.
Each year, this cycle repeats and the ice wedges get bigger. If one is exposed to the air in warm months, it can melt. The melting causes thaw lakes, which release methane into the atmosphere. As Arctic temperatures rise, thaw lakes get bigger and emit more methane.single page
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.