When the Antarctic wants to rid itself of ice, it has to get creative. The cold is too stubborn to allow surface ice to gently melt into oblivion. Instead, crushed by the immense build-up, ice gets shoved slowly along valleys and gorges until it finally reaches the edge of the continent, walking the plank into its watery grave. Back in the 1980s, scientists would plant stakes on these so-called “ice streams” to see how fast (or how slowly) they moved.