#icebridge

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.

Strange icebergs

NASA’s annual endeavour called Operation Icebridge that keeps tabs on the changing cryosphere in our fast warming world often brings sightings of odd and interesting features in the world’s frozen regions (see https://bit.ly/2qQefLx). The latest crop features a couple of interesting rectangular tablets of ice spotted in mid October in the sea washing the northern Antarctic Peninsula (the bit that juts out towards the tip of South America), just off the Larsen C ice shelf that the flight from Punta Arenas in Chile had set out to monitor (see https://bit.ly/2Q6TNV2). The operation’s deployment for this year ends tomorrow. Another interesting iceberg makes a telling point about the fate of the world’s ice (when there last was this much CO2 in our atmosphere there was no frozen water to be found anywhere on the planet’s surface). Part of the remnants of a huge calving event 18 years ago in the Ross ice shelf (also in Antarctica) it is shaped like a coffin, describing metaphorically the now near inevitable fate of the world’s cryosphere. Having spent years refining its shape as it circled the White Continent in the Circumpolar Current, B-15T as it is known has now shifted north into warmer waters, where it will melt away. The photo with the layer of cloud above it was taken from the International Space Station.

Loz

Image credit: NASA 2: NASA/Jeremy Harbeck

NASA's Antarctic Flyover Reveals Ice in Retreat

A snowshoe hare is alerted near Thule Air Base in Pituffik, Greenland. Nasa’s Operation IceBridge is flying research missions out of Thule and other Arctic locations during their annual Arctic spring campaign. Thule is the US military’s northernmost base located some 750 miles above the Arctic Circle.

For the first time ever, we've found a massive crater hiding under one of Earth's ice sheets. Likely caused by a meteor, it was uncovered in Greenland by a team of international scientists using radar data.

The data was collected by missions like our Operation IceBridge, which flies planes over Greenland and Antarctica to study the ice and snow at our planet’s poles.

In this case, the crater is near Hiawatha Glacier, covered by a sheet of ice more than half a mile thick. We're pretty sure that the crater was caused by a meteor because it has characteristics traditionally associated with those kinds of impacts, like a bowl shape and central peaks.

It’s also one of the 25 largest impact craters in the world, large enough to hold the cities of Paris or Washington, D.C. The meteor that created it was likely half a mile wide.

Currently, there’s still lots to learn about the crater – and the meteor that created it – but it’s likely relatively young in geologic timescales. The meteor hit Earth within the last 3 million years, but the impact could have been as recent as 13,000 years ago.

While it was likely smaller than the meteor credited with knocking out the dinosaurs, this impact could have potentially caused a large influx of fresh water into the northern Atlantic Ocean, which would have had profound impacts for life in the region at the time.

Go here to learn more about this discovery: https://www.nasa.gov/press-release/international-team-nasa-make-unexpected-discovery-under-greenland-ice

Operation IceBridge continues to uncover the hidden secrets under Earth's ice. IceBridge has been flying for 10 years, providing a data bridge between ICESat, which flew from 2003 to 2009, and ICESat-2, which launched in September. IceBridge uses a suite of instruments to help track the changing height and thickness of the ice and the snow cover above it. IceBridge also measures the bedrock below the ice, which allows for discoveries like this crater.

Each year since 2009, geophysicist and pilot Chris Larsen has led two sets of flights to monitor Alaska’s mountain glaciers. From the air, scientists like Larsen collect critical information on how the region’s snow and ice is changing. They also are in a good position to snap photographs of the stunning landscape. Larsen was flying with NASA science writer Maria-Jose Viñas on board. During a flight on August 19, 2018, Viñas shot this photograph during a mission to survey Yakutat Icefield and nearby glaciers in southeast Alaska.

The beach and stream in the photograph are in Russel Fjord near the terminus of the Hubbard Glacier. While this photograph does not show any glaciers, evidence of their presence is all around. Meltwater winds down a vegetation-free path of glacial till. On its way toward open water, the stream cuts through a beach strewn with icebergs. “The Hubbard Glacier has a broad and active calving front providing a generous supply of icebergs,” said Larsen, a researcher at the University of Alaska, Fairbanks. “They are present all summer since new ones keep coming from the glacier.”

NASA’s Operation IceBridge makes lengthy flights each year over the landmasses of Greenland and Antarctica and their surrounding sea ice. While IceBridge-Alaska flights are shorter in length, the terrain is equally majestic and its snow and ice important to monitor. Wherever IceBridge flights are made, data collection depends in part on weather and instruments.

Read more: https://go.nasa.gov/2Mj48r0

Appat island The icy island continent of Greenland has a variety of smaller isles spread around it, including this currently uninhabited and cold seeming place located near Thule air force base, a mainstay of the cold war. Located off the north-western coast in a fiord system that discharges into Baffin bay, it was inhabited by a small settlement that exploited a marble quarry that opened in 1755, and was later abandoned. The plateau lying above the steep cliffs is glaciated and peaks at 1,688 metres, and the island remains isolated by sea ice for much of the year. It can only be reached by chartered boat or helicopter, making it a truly remote destination. Loz