NASA is currently working on a new project to measure, map, analyse and document the loss of ice from Greenland to gain a better understanding of how warmer ocean waters melt ice from below.
NASA is taking a bottom up approach to researching sea ice melt, launching a five-year project, titled Oceans Melting Greenland (or OMG for short), that looks at the role that warm, salty water from the Atlantic Ocean plays in melting glaciers and where exactly this is occurring.
Over the last 140 years, global ocean temperature has risen one degree (although water around southern Greenland and Iceland has, lately, has been bucking this trend, which you can read more about here). In instances where this warmer water flows from the Atlantic Ocean to Greenland, it melts the glaciers from below, while rising temperatures in the atmosphere melt the glaciers from the top down. With a coastline that's dotted with hundreds of fjords (many containing glaciers of different sizes and expanses), pinpointing exactly where this happens and at what rate is, however, no easy task.
To get a better understanding of this, NASA will monitor the change in water temperature on the continental shelf surrounding Greenland as well as look at what happens to glaciers when warmer ocean waters reach this area. A customised fishing boat has spent this past summer mapping the seafloor around the island. Next year, NASA will use its G-III research aircraft – equipped with a topographical measuring instrument - to fly over and around the island, examining the heights and extents of 90 percent of Greenland's glaciers. The data will be gathered from 2016 until 2020 and will allow scientists to compare levels of melt over an extended period of time.
The data gathered will enable deeper insight into how the ocean (and in particular, warm water) interacts with ice and will help scientists make improved predictions about sea level rise, helping to bring some more detailed understanding of how the melting of the Greenland Ice Sheet will effect future sea level rises, particularly due to the sheer size of it. According to a blog post on NASA's Jet Propulsion Laboratory page, "at about 660,000 square miles (1.7 million square kilometers), the ice sheet is three times the size of Texas. It's about a mile deep on average and contains enough water to raise global sea levels about 20 feet (6 meters), if it were all to melt."
For more info on the project head to the NASA website. For more info on sea ice melt and sea levels rising, take a look at the video below or check out this fact sheet on the topic from the Union of Concerned Scientists.