Operation IceBridge

Pine Island Glacier is one of many outlet glaciers around the perimeter of Antarctica, but observations have shown that this glacier is worth extra attention. It is, along with neighboring Thwaites Glacier, one of the main pathways for ice entering the Amundsen Sea from the West Antarctic Ice Sheet and one the fastest-retreating glaciers in Antarctica. Collectively, the region contains enough vulnerable ice to raise global sea level by 1.2 meters (4 feet). Operation IceBridge routinely surveyed the glacier during its annual missions over the continent.

The Airborne Topographic Mapper (ATM), developed at NASA Wallops Flight Facility in Wallops Island, Va., is a scanning laser altimeter that measures changes in ice surface elevation. It accomplishes this by reflecting lasers off the ice surface and measuring the time it takes light to return to the aircraft, usually flying between 1000 and 2000 feet above the ground. By combining this timing data with detailed information about the aircraft’s position and attitude from GPS and inertial navigation systems, ATM can measure topography to an accuracy of as small as four inches. By flying ATM over the same swath of ground previously covered by ICESat, researchers can maintain a record of changes. In addition, the precise data from ATM’s navigation system can be fed to pilot displays in the cockpit or even electronically sent to the automatic pilot system, keeping the aircraft aligned with the planned survey track. This keeps the aircraft along the planned ATM survey swath and also benefits the other IceBridge instruments by minimizing aircraft roll and horizontal acceleration.

NASA is carrying out its sixth consecutive year of Operation IceBridge research flights over Antarctica in 2014 to study changes in the continent’s ice sheet, glaciers and sea ice. For several weeks, researchers flew aboard NASA’s DC-8 research aircraft out of Punta Arenas, Chile.

NASA's P-3B and DC-8 airborne laboratories have been the workhorses of Operation IceBridge. These aircraft house several sophisticated instruments for measuring snow depth, ice elevation and thickness, surface temperature, bed topography and other characteristics of sea ice, ice sheets and glaciers.

NASA's P-3B and DC-8 airborne laboratories have been the workhorses of Operation IceBridge. These aircraft house several sophisticated instruments for measuring snow depth, ice elevation and thickness, surface temperature, bed topography and other characteristics of sea ice, ice sheets and glaciers. The airborne laboratories have been joined by other aircraft, such as NASA's C-130 Hercules, King Air B-200 and HU-25C Falcon, the Gulfstream G-V owned by the National Science Foundation and operated by NCAR’s Research Aviation Facility, the University of Texas Institute for Geophysics' (UTIG) chartered Kenn Borek Basler BT-67, and a variety of small planes used by researchers from the University of Alaska-Fairbanks (UAF). These aircraft increase the number of instruments IceBridge can field at one time, greatly expand the geographic area covered and add a higher-altitude perspective on polar ice.

Operation IceBridge, NASA’s longest-running aerial survey of polar ice, flew over the northern Antarctic Peninsula on Oct. 16, 2018. During the survey, designed to assess changes in the ice height of several glaciers draining into the Larsen A, B and C embayments, IceBridge senior support scientist Jeremy Harbeck spotted a very sharp-angled, tabular iceberg floating among sea ice just off of the Larsen C ice shelf.

Ice shelves are the floating parts of ice streams and glaciers, and they buttress the grounded ice behind them; when ice shelves collapse, the ice behind accelerates toward the ocean, where it then adds to sea level rise.

Larsen C, a floating platform of glacial ice on the east side of the Antarctic Peninsula, is the fourth-largest ice shelf on the coast of Antarctica.

Tabular icebergs float near the Weddell Sea in Antarctica

For ten years from 2009 to 2019, the planes of NASA’s Operation IceBridge flew above the Arctic and Antarctic, gathering data on the height, depth, thickness, flow and change of sea ice, glaciers, and ice sheets. Designed to bridge the gap between NASA’s two Ice, Cloud, and land Elevation Satellites, ICESat and ICESat-2, IceBridge made its final flight in November 2019, one year after ICESat-2’s successful launch. The fleet of aircraft carried more than a dozen instruments, from ice-penetrating radar and elevation-mapping lasers to optical and infrared cameras. This visualization shows the flight lines of each yearly campaign from 2009 to 2019, created from navigational data obtained from the flights.

The Greenland Ice Sheet holds enough water to raise the world’s sea level by over 7 meters (23 feet). Rising atmosphere and ocean temperatures have led to an ice loss equivalent to over a centimeter increase in global mean sea-level between 1991 and 2015. Large outlet glaciers, rivers of ice moving to the sea, drain the ice from the interior of Greenland and cause the outer margins of the ice sheet to recede. Improvements in measuring the ice thickness in ice sheets is enabling better simulation of the flow in outlet glaciers, which is key to predicting the retreat of ice sheets into the future. Recently, a simulation of the effects of outlet glacier flow on ice sheet thickness coupled with improved data and comprehensive climate modeling for differing future climate scenarios has been used to estimate Greenland’s contribution to sea-level over the next millennium. Greenland could contribute 5–34 cm (2-13 inches) to sea-level by 2100 and 11–162 cm (4-64 inches) by 2200, with outlet glaciers contributing 19–40 % of the total mass loss. The analysis shows that uncertainties in projecting mass loss are dominated by uncertainties in climate scenarios and surface processes, followed by ice dynamics. Uncertainties in ocean conditions play a minor role, particularly in the long term. Greenland will very likely become ice-free within a millennium without significant reductions in greenhouse gas emissions. Three visualizations of the evolution of the Greenland Ice Sheet between 2008 and 2300 based on three different climate scenarios are shown below. Each scenario is described briefly in the caption under each visualization. Each of the three visualizations are provided with a date and colorbar as well as without. The regions shown in a violet color are exposed areas of the Greenland bed that were covered by the ice sheet in 2008. The data sets used for these animations are the control (“CTRL”) simulations and were produced with the open-source Parallel Ice Sheet Model (www.pism-docs.org). All data sets for this study are publicly available at https://arcticdata.io (doi:10.18739/A2Z60C21V).

The Greenland Ice Sheet holds enough water to raise the world’s sea level by over 7 meters (23 feet). Rising atmosphere and ocean temperatures have led to an ice loss equivalent to over a centimeter increase in global mean sea-level between 1991 and 2015. Large outlet glaciers, rivers of ice moving to the sea, drain the ice from the interior of Greenland and cause the outer margins of the ice sheet to recede. Improvements in measuring the ice thickness in ice sheets is enabling better simulation of the flow in outlet glaciers, which is key to predicting the retreat of ice sheets into the future. Recently, a simulation of the effects of outlet glacier flow on ice sheet thickness coupled with improved data and comprehensive climate modeling for differing future climate scenarios has been used to estimate Greenland’s contribution to sea-level over the next millennium. Greenland could contribute 5–34 cm (2-13 inches) to sea-level by 2100 and 11–162 cm (4-64 inches) by 2200, with outlet glaciers contributing 19–40 % of the total mass loss. The analysis shows that uncertainties in projecting mass loss are dominated by uncertainties in climate scenarios and surface processes, followed by ice dynamics. Uncertainties in ocean conditions play a minor role, particularly in the long term. Greenland will very likely become ice-free within a millennium without significant reductions in greenhouse gas emissions. Three visualizations of the evolution of the Jakobshavn region of the Greenland Ice Sheet between 2008 and 2300 based on three different climate scenarios are shown below. Each scenario is described briefly in the caption under each visualization. Each of the three visualizations are provided with a date, colorbar and a distance scale as well as without. The regions shown in a violet color are exposed areas of the Greenland bed that were covered by the ice sheet in 2008. The data sets used for these animations are the control (“CTRL”) simulations and were produced with the open-source Parallel Ice Sheet Model (www.pism-docs.org). All data sets for this study are publicly available at https://arcticdata.io (doi:10.18739/A2Z60C21V).

The Greenland Ice Sheet holds enough water to raise the world’s sea level by over 7 meters (23 feet). Rising atmosphere and ocean temperatures have led to an ice loss equivalent to over a centimeter increase in global mean sea-level between 1991 and 2015. Large outlet glaciers, rivers of ice moving to the sea, drain the ice from the interior of Greenland and cause the outer margins of the ice sheet to recede. Improvements in measuring the ice thickness in ice sheets is enabling better simulation of the flow in outlet glaciers, which is key to predicting the retreat of ice sheets into the future. Recently, a simulation of the effects of outlet glacier flow on ice sheet thickness coupled with improved data and comprehensive climate modeling for differing future climate scenarios has been used to estimate Greenland’s contribution to sea-level over the next millennium. Greenland could contribute 5–34 cm (2-13 inches) to sea-level by 2100 and 11–162 cm (4-64 inches) by 2200, with outlet glaciers contributing 19–40 % of the total mass loss. The analysis shows that uncertainties in projecting mass loss are dominated by uncertainties in climate scenarios and surface processes, followed by ice dynamics. Uncertainties in ocean conditions play a minor role, particularly in the long term. Greenland will very likely become ice-free within a millennium without significant reductions in greenhouse gas emissions. Three visualizations of the evolution of the Jakobshavn region of the Greenland Ice Sheet between 2008 and 2300 based on three different climate scenarios are shown below. The camera zooms in slowly as the ice sheet retreats and pulls out to a view of the entire ice sheet in the year 2300. Each scenario is described briefly in the caption under each visualization. Each of the three visualizations are provided with a date, colorbar and a distance scale as well as without. The regions shown in a violet color are exposed areas of the Greenland bed that were covered by the ice sheet in 2008. The data sets used for these animations are the control (“CTRL”) simulations and were produced with the open-source Parallel Ice Sheet Model (www.pism-docs.org). All data sets for this study are publicly available at https://arcticdata.io (doi:10.18739/A2Z60C21V).

It is increasingly rare to find new large impact craters on Earth, let alone such craters buried beneath ice. This study by MacGregor et al. describes a possible impact crater buried beneath two kilometers of ice in northwest Greenland. The circular structure is more than 36 kilometers wide, and both its shape and other geophysical properties are consistent with an impact origin. If eventually confirmed as an impact crater, it would be only the second found beneath either of Earth’s ice sheets. The first was the Hiawatha impact crater, which is also in northwest Greenland and only 183 kilometers away from this new structure, so this team also evaluated whether these two craters could be related. They are similarly sized, but the candidate second crater appears more eroded and ice above it is much less disturbed than above the Hiawatha impact crater. Statistical analysis of the frequency of two unrelated but nearby large impacts indicates that it is improbable but not impossible that this pair is unrelated. This study expands knowledge of the impact history of the Earth and raises the question as to how many other impact craters buried beneath ice have yet to be found.

With the aircraft resources of NASA's Airborne Sciences Program, Operation IceBridge is taking to the sky to ensure a sustained, critical watch over Earth's polar regions. Flight lines (black) are shown for the 2011 campaign over Arctic sea ice and Greenland's land ice. Many flights target outlet glaciers along the coast where NASA's Ice, Cloud and land Elevation Satellite (ICESat) shows significant thinning. Blue and purple colors, respectively, indicate moderate to large thinning. Gray and yellow, respectively, indicate slight to moderate thickening. Since its launch in January 2003, the ICESat elevation satellite has been measuring the change in thickness of ice sheets. This image of Greenland shows the changes in elevation over the Greenland ice sheet between 2003 and 2006.

This animation shows glacier changes detected by ATM, ICESat and ice bridge data in the highly dynamic Amundsen Embayment of West Antarctica. We know that ice speeds in this area have increased dramatically from the late 1990s to the present as the ice shelves in this area have thinned and the bottom of the ice has lost contact with the bed beneath. As the ice has accelerated, ice upstream of the coast must be stretched more vigorously, causing it to thin. NASA-sponsored aircraft missions first measured the ice surface height in this region in 2002, followed by ICESat data between 2002 and 2009. Ice Bridge aircraft have measured further surface heights in 2009 and 2010, and these measurements continue today. Integrating these altimetry sources allows us to estimate surface height changes throughout the drainage regions of the most important glaciers in the region. We see large elevation changes at the coast on Thwaites glacier, at the center of the images, and large and accelerating elevation changes extending inland from the coast on Pine Island and Smith glaciers, to the left and right of the images, respectively. The changes on Pine Island and Smith glaciers mark these as potential continuing sources of ice to the sea, and they have been surveyed in 2011 by Ice Bridge aircraft and targeted for repeat measurements in coming years.

Laser and radar instruments aboard NASA aircraft provide measurements of the snow and ice surface and down to the bedrock under the ice. Lasers, with a shorter wavelength, measure the surface elevation of the snow or ice to within a fraction of an inch. Radar instruments utilize a longer wavelength and can penetrate the ice to "see" below the surface, providing a profile of ice characteristics and also the shape of the bedrock. This information is critical for understanding how and why the world's biggest ice masses are changing.

Hidden for all of human history, a 460 mile long canyon has been discovered below Greenland's ice sheet. Using radar data from NASA's Operation IceBridge and other airborne campaigns, scientists led by a team from the University of Bristol found the canyon runs from near the center of the island northward to the fjord of the Petermann Glacier.

A large portion of the data was collected by IceBridge from 2009 through 2012. One of the mission's scientific instruments, the Multichannel Coherent Radar Depth Sounder, operated by the Center for the Remote Sensing of Ice Sheets at the University of Kansas, can see through vast layers of ice to measure its thickness and the shape of bedrock below.

This is a narrated version of an visualization that can be found, along with more detailed information, at

Greenland's Mega-Canyon beneath the Ice Sheet (#4097).

For nearly a century, scientists have been studying the form and flow of the Greenland Ice Sheet. They have measured the change in the elevation of the surface over time using satellites. They have drilled ice cores in the field to reveal a record of what the past climate was like. They have flown aircraft over the surface of the ice sheet laden with instruments to gleen information about the interior of the ice sheet and the bedrock below. Now a new analysis of this data has revealed a three dimensional map of the age of the ice sheet. This visualization shows this new 3D age map of the Greenland Ice Sheet, explains how it was created and describes the three distinct periods of climate that are evident within the ice sheet. More information is available here.

Operation Ice Bridge (OIB) has been flying annual airborne missions over the Helheim Glacier in Greenland since 1997. These missions record the elevation of the glacier along a long, thin track near the middle of the glacier. This record of heights helps scientists see how the glacier has changed over the years. This visualization shows OIB tracks from each year in sequence. The camera then moves to the side to compare the ice profiles on a graph. The track profiles are shown to scale (i.e., no exaggeration) until they are compared on the graph where they are exaggerated 10 times to help see the changes. The initial camera for this animation matches the end of the Helheim visualization (#4348). Image layers are included for each track and the graph for those wishing to create different composites.