You may never make it to the South Pole, but you can now see Antarctica and its glaciers in unprecedented detail.
Researchers this week announced the release of a new high resolution terrain map of the southernmost continent, called the Reference Elevation Model of Antarctica, or REMA, which they say makes Antarctica the best mapped continent on Earth.
Antarctica is the most desolate and inhospitable place on Earth and its remoteness makes monitoring changes in the fluctuations of ice and water levels difficult. Because of the warming climate, seasonal changes at Antarctica are becoming more severe, making the need to understand the loss of ice even more important.
Ian Howat, the project’s principal investigator and a professor of earth sciences at Ohio State University, and Paul Morin, of the University of Minnesota, used data from a constellation of polar orbiting satellites to image the frozen wastes. The satellites are owned by the National Geospatial-Intelligence Agency, which is part of the Department of Defense.
Previous maps of the continent had a resolution similar to seeing the whole of Central Park from a satellite. With this new data, it is now possible to see down to the size of a car, and even smaller in some areas. The data is so complete that scientists now know the height of every feature on the continent down to a few feet.
“If you’re someone that needs glasses to see, it’s a bit like being almost blind and putting on glasses for the first time and seeing 20/20,” said Dr. Howat.
The team used 187,585 images collected over six years to create the map.
“Until now, we’ve had a better map of Mars than we’ve had of Antarctica,” said Dr. Howat.
The pictures are so detailed they had to use one of the most powerful supercomputers on Earth to ingest the data. Having access to this amount of information will allow researchers to better monitor the effects of climate change on the ice.
Previous images of Antarctic terrain left much to be desired. The difference between two images from previous surface imaging on the left and the new map on the right demonstrates the difference.
The upturned shovel feature in the bottom right is called Siple Dome. Hills like these are found all over Antarctica, their smooth surface made by accumulations of ice. The large mounds act like obstructions in this stream of glacial ice that is flowing out to the Ross ice shelf, Antarctica’s largest.
Observing snowfall, ice-growth and the rate of melt and fissures will allow scientists to monitor sea-level rise and glacial melt with more accuracy. Ice shelves bear the brunt of pressure from flowing rivers pushing against them. The faster the ice melts on the land, the more weight the ice shelf has to contain, resulting in breaks of glaciers into the sea.
Scientists who keep a close watch on large ice shelves like Larsen C, above, will now be able to study the streams of ice and stress fractures that occur between the mountains. Because of the location of Antarctica and because the rest of the year there isn’t enough sunlight at the poles for the satellites to see the land, images can only be taken from December through March, the summer season. Since the last set of data was collected, a large section of this glacier has broken off into an iceberg named A-68.
This is a large river of ice flowing between two mountains called the Glacier South of Dry Valley. Images like these will be free and accessible to scientists for their research.
Explorers and scientists stationed at Antarctica will also find the new map useful. By having such a detailed topographical map, new routes to science stations can be planned around the continent’s dangerous terrain.
At the center of this image above are two locations called Halley V & VI. Both were British research bases. They have since had to move because the ice shelf began to break off.
“Something that’s always been a problem is knowing where the ice is and knowing how thick it is,” Dr. Howat said.
The 150 terabyte data set is the first that will allow researchers to watch the fracturing of ice shells within a three week time span, nearly tracking changes on the ice in real time. These streams are flowing into Filchner ice shelf where stress fractures can be seen forming between hills. Such fractures are often the early signs of a full break from the glacier.
Dr. Howat and Mr. Morin hope to update the map every year. With REMA it will be possible to watch icebergs forming and glaciers moving like this flow of ice at Byrd Glacier, which is the largest ice stream on Antarctica.