It's taken roughly five months, but a massive iceberg has separated from Antarctica's Pine Island Glacier. According to NASA's Earth Observatory, the estimated size of this iceberg, named B-31, is around 660 square kilometres (33 km long by 20 km wide) – a city-sized block of ice that has slowly migrated away from the continent, and is now floating out to sea. Take a look at some massive icebergs afloat in the oceans. Photo: File photo of an iceberg floating near a harbour in the town of Kulusuk, east Greenland August 1, 2009. (Photo by Bob Strong/Reuters)

“Just hanging out”. As full autumn hits the valley of Hallingdal in Norway, this bear chills out in a tree which seems to barely cover its weight. Photo location: Flå, Hallingdal, Norway. (Photo and caption by Jorgen Tharaldsen/National Geographic Photo Contest)

A pro-Russian activist aims a pistol at supporters of the Kiev government during clashes in the streets of Odessa May 2, 2014. Police said a man was shot dead in clashes between a crowd backing Kiev and pro-Russian activists in the largely Russian-speaking southern port of Odessa, which lies west of Crimea, annexed by Moscow in March. (Photo by Yevgeny Volokin/Reuters)

A model walks off stage in the backstage area during Frankie's Bikinis show at Mercedes Benz Swim Fashion Week in Miami, July 18, 2014. (Photo by Carlo Allegri/Reuters)

An Israeli girl in costume, celebrates the Jewish festival of Purim on March 5, 2004, in Tel Aviv, Israel. The Festival commemorates the rescue of Jews from genocide in ancient Persia.

Esau the ape at the piano. (Photo by Reinhold Thiele/Topical Press Agency/Getty Images). Circa 1900

A group of children and their dog playing an Easter game in Cardiff. The game involves trying to eat an Easter egg off a piece of string without using their hands. (Photo by Richards/Fox Photos/Getty Images). 26th March 1937

From the waters edge a New York policeman urges two young children to put their bathing costumes back on. (Photo by Ed Clarity/Keystone/Getty Images). July 1949