Four-mile-long iceberg breaks off Greenland glacier in dramatic video

The research team is now studying the forces behind sea-level rise-a development that has concerned scientists in recent decades because it points to the possibility of global disruptions due to climate change-under a grant from the National Science Foundation.

This phenomenon, also known as calving (the breaking off of large blocks of ice from a glacier), may also be instructive to scientists and policy makers. The chunk of ice that broke away from Greenland's Helheim Glacier during this particular calving event was huge, measuring 6 kilometers (4 miles) in length.

Calving is when an iceberg breaks off from a glacier.

The event plays out over 30 minutes, though the video has been condensed to around 90 seconds and shows a front-on angle of the glacier's edge, followed by a perspective further down the fjord. The researchers saw, LiveScience reports, "puffs of ice" tossed into the air as a new iceberg began to break off from the glacier.

Understanding how calving events take place is, the researchers say, important for developing simulations for sea-level rise brought about by climate change. "By capturing how it unfolds, we can see, first-hand, its breath-taking significance".

Strike talks will go ahead after Ryanair backs down
According to the airline, Ireland to Europe flights will operate as normal, as the majority of Irish pilots fly on Thursdays. It said it would also help customers travelling to the United Kingdom with alternative flights and ferries.

The vast piece of ice that breaks away is described as a tabular iceberg because it is wide and flat.

While it's hard to get a sense of scale from the camera's wide-angle view of the separating iceberg, the berg is so big that it could partially cover the island of Manhattan, extending from the lower tip of New York City into Midtown, according to the statement.

It only took 30 minutes for an iceberg almost half the size of Manhattan to separate from a glacier in Greenland. The video above has been sped up. For example, if the Western Antarctic Ice Sheet were to break off into the sea it would result in a 10ft rise in the global sea level, enough to completely submerge New York City, a 2017 estimate suggested.

There's an otherworldly quality to the footage, like you're watching a special-effects scene from beyond The Wall in Game of Thrones.

"Global sea-level rise is both undeniable and consequential", said NYU Abu Dhabi professor David Holland. "The better we understand what's going on means we can create more accurate simulations to help predict and plan for climate change".