A team of scientists from the UK have discovered an immense sub-glacial trench — deeper than the Grand Canyon — in West Antarctica, and their findings show that this may be the location where the entire West Antarctica ice sheet originated!
A few years ago, UK scientists had mapped out the northwestern portion of what's now known as the Ellsworth Trough, in their efforts to drill down to a lake below the glacial ice. Now, researchers from several UK universities have spent three seasons examining the rest of the trough, which lies in ancient mountain range buried under the ice of West Antarctica, called the Ellsworth Subglacial Highlands. Pulling ice-penetrating radar across the highlands with skidoos and using it from small aircraft, as well as adding satellite data to fill in the gaps, they've charted this range and full extend of the trough. It measures more than 300 kilometres long, up to 25 kilometres wide, and up to 3,000 metres deep. In some areas of this valley, the bottom is more than 2 kilometres below sea level! For comparison, that's about two-thirds the length of the Grand Canyon, but it's over 1.5 times as deep!
"We had acquired ice penetrating radar data from both ends of this huge hidden valley, but we had no information to tell us what was in between," said lead author Dr. Neil Ross, in a Newcastle University press release. "Satellite data was used to fill the gap, because despite being covered beneath several kilometres of ice, the valley is so vast that it can be seen from space."
According to the researchers, the Ellsworth Subglacial Highlands and this immense, newly-discovered valley were carved by an ice-field like those seen in the Canadian Arctic. Their data shows that this is where the West Antarctic ice sheet originated from and where it retreats to in warmer time periods.
"By looking at the topography beneath the ice sheet," said Prof. Martin Siegert, of the University of Bristol, according to a statement, "we have revealed a region which possesses classic glacial geomorphic landforms, such as u-shaped valleys and cirques, that could only have been formed by a small ice cap, similar to those seen at present in the Canadian and Russian High Arctic. The region uncovered is, therefore, the site of ice sheet genesis in West Antarctica."
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With this discovery following both the new 'hidden Antarctica' map and finding another immense canyon under the Greenland icesheet back in August, we're really gaining a much better view of has long been hidden from us by glacial ice.
In addition to uncovering this new trough, this study is providing a brand new look into the full extent of the West Antarctic ice sheet, as well as its thickness and its behaviour. With the ice sheet losing over 100 billion tons of ice every year due to global warming, and that rate expected to increase in the future, the researcher's findings are also providing insight into what the ice sheet's size and shape may look like as our global climate warms.
(Images courtesy: Newcastle University, British Antarctic Survey)
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