Antarctica shed an iceberg of mind-boggling size from its Larsen C ice shelf this week .
The block of ice — one of the largest ever documented — will likely be given the unceremonious name of A68 by the US National Ice Center, whose abbreviations denote both an iceberg’s location and order of discovery.
Iceberg A68 now begins a long journey into the Southern Ocean and toward its doom: as liquid in Earth’s vast and complex system of water.
Here’s how scientists discovered the giant iceberg, how it calved, and how it will eventually die — and be reborn.
In 2015, glaciologist Daniela Jansen discovered a growing crack in Antarctica’s Larsen C ice shelf, which was then the fourth-largest ice shelf on the continent. The shelf is hundreds of years old, maybe more.
Ice shelves like Larsen C formed after millennia’s worth of snow covered Antarctica in a mile-thick sheet of ice from its bedrock to its surface.
Source: NASA Goddard Space Flight Center
Gravity tirelessly pulls that ice toward the sea, where it pushes onto water to form gigantic shelves.