A mammoth iceberg that broke off earlier this month from the Mertz Glacier Tongue in Antarctica, poses a risk to ocean current circulation, and has implied changes to climate. The iceberg broke free after a collision with an older iceberg known as B9B, both icebergs are now floating in the Southern Ocean towards the Eastern Antarctic. To put things into perspective, the iceberg is 985 square miles in area, roughly the size of Luxembourg, and nearly 1300 feet thick.
While floating in the Southern Ocean, the iceberg could trouble polynyas. Polynyas are basically areas of unfrozen water surrounded in part by sea ice. The cold, dense, high-salinity water in these areas sinks, driving the circulation of ocean currents.
If the icebergs move away from their current area, they won’t be a problem, but if they continue on their path, they may put a lid on some polynyas. While the effect won’t be notice for decades, this event may lead to less temperate winters in the North Atlantic. The iceberg will eventually melt away, but even that would take decades.