Iceberg A23a measures 40 by 32 nautical miles, according to the U.S. National Ice Center. For comparison, Hawaii's island of Oahu is 44 miles long and 30 miles across .

Iceberg A23a measures 40 by 32 nautical miles, according to the U.S. National Ice Center. For comparison, Hawaii's island of Oahu is 44 miles long and 30 miles across .

The world's largest iceberg, A23a, is moving into the open waters near Antarctica after being essentially stuck in place for decades. It's seen here in satellite imagery from Nov. 15.

"It's a trillion tons of ice," as one expert told NPR. Now the largest iceberg in the world, A23a, is on the move after decades of being grounded on the seafloor.

While B-22A is a large iceberg, it isn't anywhere near the largest one ever recorded. That record is held by an iceberg called B-15, which measured a massive 4,247 square miles, ...

Icebergs are large chunks of ice that break off, or calve, from glaciers or ice shelves. This particular one, with a scientific name of A23a, calved from the Filchner Ice Shelf in 1986.

Antarctica World's largest iceberg, A23a, ... "We are interested to see if it will take the same route the other large icebergs that have calved off Antarctica have taken.

Iceberg A23a measures 40 by 32 nautical miles, according to the U.S. National Ice Center. For comparison, Hawaii's island of Oahu is 44 miles long and 30 miles across .

"It's a trillion tons of ice," as one expert told NPR. Now the largest iceberg in the world, A23a, is on the move after decades of being grounded on the seafloor.

"It's a trillion tons of ice," as one expert told NPR. Now the largest iceberg in the world, A23a, is on the move after decades of being grounded on the seafloor.