Ice Sheets - Blog Posts

Perfect 10: A Decade of Studying Ice from the Sky

From 2009 through 2019, our Operation IceBridge flew planes above the Arctic, Antarctic and Alaska, measuring the height, depth, thickness, flow and change of sea ice, glaciers and ice sheets.

IceBridge was designed to “bridge” the years between NASA’s two Ice, Cloud, and land Elevation Satellites, ICESat and ICESat-2. IceBridge made its final polar flight in November 2019, one year after ICESat-2’s successful launch.

A lot of amazing science happens in a decade of fundamentally changing the way we see ice. Here, in chronological order, are 10 of IceBridge’s most significant and exciting achievements.

2009: Go for launch

The first ICESat monitored ice, clouds, atmospheric particles and vegetation globally beginning in 2003. As ICESat neared the end of its life, we made plans to keep measuring ice elevation with aircraft until ICESat-2’s launch.

ICESat finished its service in August 2009, leaving IceBridge in charge of polar ice tracking for the next decade.

2009: Snow on sea ice

To measure how thick sea ice is, we first have to know how much snow is accumulated on top of the ice. Using a snow radar instrument, IceBridge gathered the first widespread data set of snow thickness on top of both Arctic and Antarctic sea ice.

2009: Getting to the bottom of glaciers 

IceBridge mapped hundreds of miles of grounding lines in both Antarctica and Greenland. Grounding lines are where a glacier’s bottom loses contact with the bedrock and begins floating on seawater – a grounding line that is higher than rock that the ice behind it is resting on increases the possibility of glaciers retreating in the future. 

The team mapped 200 glaciers along Greenland’s coastal areas, as well as coastal areas, the interior of the Greenland Ice Sheet and high-priority areas in Antarctica.

2011: Spotting cracks in the ice

While flying Antarctica in 2011, IceBridge scientists spotted a massive crack in Pine Island Glacier, one of the fastest-changing glaciers on the continent. The crack produced a new iceberg that October.

Pine Island has grown thinner and more unstable in recent decades, spawning new icebergs almost every year. IceBridge watched for cracks that could lead to icebergs and mapped features like the deep water channel underneath Pine Island Glacier, which may bring warm water to its underside and make it melt faster.

2013: Making a map of rock

Using surface elevation, ice thickness and bedrock topography data from ICESat, IceBridge and international partners, the British Antarctic Survey created an updated map of the bedrock beneath Antarctic ice.

Taking gravity and magnetic measurements helps scientists understand what kind of rock lies below the ice sheet. Soft rock and meltwater make ice flow faster, while hard rock makes it harder for the ice to flow quickly.

2013: Surprises under the ice

IceBridge’s airborne radar data helped map the bedrock underneath the Greenland Ice Sheet, revealing a previously unknown canyon more than 400 miles long and up to a half mile deep slicing through the northern half of the country.

The “grand canyon” of Greenland may have once been a river system, and today likely transports meltwater from Greenland’s interior to the Arctic Ocean.

2015: It’s what’s inside (the ice sheet) that counts

After mapping the bedrock under the Greenland Ice Sheet, scientists turned their attention to the middle layers of the ice. Using both ice-penetrating radar and ice samples taken in the field, IceBridge created the first map of the ice sheet’s many layers, formed as thousands of years of snow became compacted downward and formed ice.

Making the 3D map of Greenland’s ice layers gave us clues as to how the ice sheet has warmed in the past, and where it may be frozen to bedrock or slowly melting instead.

2018: Gap bridged!

ICESat-2 launched on September 15, 2018, rocketing IceBridge into the final phase of its mission: Connecting ICESat and ICESat-2.

IceBridge continued flying after ICESat-2’s launch, working to verify the new satellite’s measurements. By conducting precise underflights, where planes traced the satellite’s orbit lines and took the same measurements at nearly the same time, the science teams could compare results and make sure ICESat-2’s instruments were functioning properly.

2018: An impact crater under the ice

Using IceBridge data, an international team of scientists found an impact crater from a meteor thousands of years in the past. The crater is larger than the city of Washington, D.C., likely created by a meteor more than half a mile wide.

2019: Flying into the sunset

In 2019, IceBridge continued flying in support of ICESat-2 for its Arctic and Antarctic campaigns. The hundreds of terabytes of data the team collected over the decade will fuel science for years to come.

IceBridge finished its last polar flight on November 20, 2019. The team will complete one more set of Alaska flights in 2020.

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