Colossal Iceberg Six Times the Size of Manhattan Puts NASA on High Alert (VIDEO)

A colossal iceberg roughly six times the size of Manhattan - one of the largest in existence - has been under close watch since it detached from Antarctica's Pine Island Glacier (PIG) in July.

NASA has released new images of the ice slab, which developed from a huge crack along the surface of PIG, whose trek towards the Southern Ocean has NASA on high alert, depending on where it ends up.

"If the iceberg stays around the Antarctic coast, it will melt slowly and will eventually add a lot of freshwater that stays in the coastal current, altering the density and affecting the speed of the current," professor Grant Bigg, of the University of Sheffield, who is monitoring the iceberg's movement, said in a statement. "Similarly, if it moves north it will melt faster but could alter the overturning rates of the current as it may create a cap of freshwater above the denser seawater."

NASA glaciologist Kelly Brunt told Reuters that the "large sheet cake," named B31, covers about 255 square miles (660 square km) and is up to a third of a mile (500 meters) thick.

While experts say icebergs normally part ways from their host glaciers - occurring every six to 10 years or so - the size, in this case, is significant.

"Iceberg calving is a very normal process," Brunt, from NASA's Goddard Space Flight Center, said in a news release. "However, the detachment rift, or crack, that created this iceberg was well upstream of the 30-year average calving front of PIG, so this is a region that warrants monitoring."

As temperatures warm and "climate change" and "global warming" became a part of our daily vocabulary, scientists have kept a close eye on PIG - the longest and fastest shrinking glacier in the Antarctic. If one massive iceberg is causing concern, multiple such events could be catastrophic.

"If these events become more common, there will be a build-up of freshwater which could have lasting effects," Biggs said.