Ultra-Wideband Radar Scanning Greenland's Glaciers Helps Predict Rising Sea Levels
By Jof Enriquez,
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A new type of ground-based, ice-penetrating radar will help scientists better understand the mechanics and changes inside the ice sheets and glaciers of Greenland, which are melting at historically fast rates that threaten to raise sea levels and inundate cities.
Developed by researchers at the University of Alabama (UA), with a nearly $1 million grant from the Danish scientific research foundation Villum Fonden, the ultra-wideband radar is designed to operate in Very High Frequency (VHF) and Ultra High Frequency (UHF) bands to penetrate deep into ice.
Specifically, it will image the base part of the ice to study and monitor the North East Greenland Ice Stream (NEGIS), which carries water into the ocean through melting at the edges of floating ice shelves and icebergs that break off.
“We need to better understand what is happening at the very base of these ice streams and glaciers to be able to incorporate them into better models that predict what an ice sheet’s contribution will be to sea level rise in the future,” stated Dr. Prasad Gogineni, the Cudworth Professor of Engineering at UA, and head of the university's Remote Sensing Center, in a press release.
The National Science Foundation (NSF), NASA, and other research groups have been using airborne radar to peer down through thick ice to map out ice sheets and their interior landforms, but the team from UA is designing a sled-based mechanical radar that will be pulled over the ice surface across 20 square miles by a vehicle moving at about 10 mph – purposely slow enough to achieve high-quality interior images and 3D topography maps of the bottom of the ice stream.
According to the researchers, their radar is 100 times more sensitive, will operate at a higher power, and will have 16 antennas that are relatively larger than current radars used to study melting and cracking ice sheets.
“Right now, there is no radar capable of imaging ice layers within the bottom 10 percent of the ice with the resolution and precision required for this project, and that’s what we are developing,” said Gogineni. “This will be a state-of-the-art radar unique in the world to do something that has not been done before.”
Along with data gained from ice core samples, images obtained from this radar will help scientists design models to more accurately predict the rate of ice melting and rise in sea levels in the coming decades until the turn of the next century.
Scientists and economists have warned of the risks of rising sea levels brought about by melting ice sheets at and near both geographic poles. In addition to Antarctica’s melting, the shrinking of Greenland’s ice sheet is worrisome because it could weaken Earth’s albedo effect (which reflects sunlight back to space), may disrupt global weather patterns, and with the island’s ice equivalent to six meters of sea level rise if melted, potentially would submerge most coastal cities, according to the World Economic Forum.