A giant glacier the size of Guam that broke off Antarctica isn't worrying scientists as much as it's amazing them.
The giant block of ice is six times the size of Manhattan, covering 225 square miles, and it's heading into the open sea. It broke off from the Pine Island Glacier in the Amundsen Sea last year and NASA officials have been watching the icy island ever since.
But scientists have kept an eye on the Pine Island Glacier for two decades ... because it's been melting rapidly - at almost 3 inches per day - due to currents of warm water flowing underneath it. Experts believe it could be an important contributor to rising sea levels.
However, one scientist told the Associated Press it's normal for icebergs to split off from glaciers. Fortunately, they say this particular block, which is more than 1,600 feet thick, doesn't put shipping traffic or sea levels at risk.
The team that's been tracking it says it will bring them new information about local ocean currents. The iceberg is expected to drift into the Southern Ocean.
Massive iceberg that dwarfs Manhattan being watched closely by scientists
NASA scientists discovered a massive crack across the Pine Island Glacier, Antarctica. Nov. 13, 2011. (Photo by: Universal History Archive/UIG via Getty Images)
Chile, Patagonia, Los Glaciares National Park, Landscape
People walking on Perito Moreno.
Argentina, Perito Moreno, Panoramic view of iceberg
Dock on Jokulsorlon lagoon with glacier in backgro