Watch: Giant Iceberg Breaks Off Glacier in Greenland

Scientists captured a colossal iceberg on video, as it broke free from a glacier in eastern Greenland in June, giving viewers around the world a visual depiction of how sea levels are rising.

Researchers from New York University shot the video of an iceberg, nearly the size of New York City, drifting into the sea after it split from a larger body of ice. This phenomenon called calving—the breaking off of large blocks of ice from glaciers— could cause the world's oceans to swell. If glaciers continue to melt and break into the sea, a large percentage of the world's population living in coastal cities could be threatened, the scientists said.

"Global sea-level rise is both undeniable and consequential," David Holland, a professor at NYU's Courant Institute of Mathematics and NYU Abu Dhabi, who led the research team, in a statement. "By capturing how it unfolds, we can see, first-hand, its breath-taking significance."

The researchers at NYU said that a 2017 estimate suggested that a collapse of the entire the Western Antarctic Ice Sheet would cause a 10-foot-rise in sea level—enough to overwhelm coastal areas around the globe, including New York City.

In the U.S. at least 123.3 million people, or 39 percent of the population, live in counties directly on the shoreline. This population is expected to increase by eight percent by 2020, according to government estimates from the National Ocean Service.

Research shows that the melting of glacier ice is accelerating. A study published last year in the journal Nature Climate found that Greenland contributed about five percent to sea level rise in 1993, but by 2014 that number had gone up to 25 percent.

In the video, viewers can see how the water literally elevates as the ice separates from the glacier. By capturing videos of the iceberg calving like this, scientists say they can study and better anticipate how this phenomenon will impact sea levels around the world.

"Knowing how and in what ways icebergs calve is important for simulations because they ultimately determine global sea-level rise," said Denise Holland, the logistics coordinator for NYU's Environmental Fluid Dynamics Laboratory and NYU Abu Dhabi's Center for Global Sea Level Change.

"The better we understand what's going on means we can create more accurate simulations to help predict and plan for climate change."