I just ran into the word pingo yesterday in reference to a possible explanation of a mysterious phenomenon in Siberia. A pingo is a frozen ball of earth and slush under the surface creating a protrusion that becomes a declivity when the pingo melts. They occur near the margins of permafrosted landscape and can be stable for decades but with climate change, pingos are melting all over the world, leaving small ponds in raw-looking dimples in the land. The oddity in Siberia is that a deep hole has been left, as if the pingo exploded instead of just melting.

Fascinating. :)

Hugs,
Erin