New Map Shows How Fast Ice is Leaving Antarctica

Satellites are being used to map areas around the world that are notoriously remote and hard to reach. Multiple satellites from different nations have now turned their lenses towards the icy continent of Antarctica to measure the rate of ice that is melting from the Earth’s southernmost pole.

Although Antarctica is classified as a desert, there is a small amount of snow and other precipitation that falls every year. This snow is compressed down into layers and layers of ice, creating shelves and glaciers that blanket the continent’s surface. As the climate continues to change, this ice is melting faster than ever and has the capacity to dramatically alter our world.

Using Synthetic-aperture Radar To Map Ice Movements

Researchers used synthetic-aperture radar (SAR) data to look at how the ice is moving and shifting. Multiple satellite data (the Canadian Space Agency’s Radarsat-1 and Radarsat-2; the European Space Agency’s Earth remote sensing satellites 1 and 2 and Envisat ASAR; and the Japan Aerospace Exploration Agency’s ALOS PALSAR-1) was compiled in order to view the Antarctic ice flow from multiple viewpoints. This method has been shown to be 10 times more precise than other methods that have been used for measuring depleting sea ice in the past. The resulting map covers more than 70 percent of Antartica and shows shows ice movement as small as 20 centimeters per year in speed and 5 degrees in annual flow direction. The goal of this data is to see how much ice is melting on the Antarctic continent and potentially to map the group beneath all this ice.

While the rapidly melting ice on the coastlines have garnered the majority of the world’s attention, researchers are interested in the slow moving ice located in the middle of the continent as well. Measuring how that ice is shifting could help chart Antarctic ice flow so that accurate forecasts about ice melt could be created with the data.

The new Antarctic ice velocity map and related datasets are available for download at the NASA Distributed Active Archive Center at the National Snow & Ice Data Center.

Future Implications

Melting ice is a big factor in the rise of sea levels. Researchers want to be able to estimate how much ice is flowing into the ocean so that predictions can be made regarding cities and other locations that are vulnerable to changes in sea level. Satellite data has been gathered to show how the ANtarctic ice flows from higher elevations to lower points near the coast. On average, the ice velocity is approximately 20 centimeters a year for 80% of the ice.

Starting in 2021, NASA will be partnering with the Indian Space Research Organization to launch a satellite that will be able to update this ice velocity map every few months, providing more accurate data for researchers to monitor the ice flow as well as melt rates in response to our ever changing climate.

The Study

Mouginot, J., Rignot, E., & Scheuchl, B. ( 2019). Continent‐wide, interferometric SAR phase, mapping of Antarctic ice velocity. Geophysical Research Letters, 46. https://doi.org/10.1029/2019GL083826

Glaciologists unveil most precise map ever of Antarctic ice velocity.  2019, July 29. AGU.

Related

• ICESat-2: Highest Resolution Laser Altimeter
• Highest Resolution DEM of Antarctica Released