Mountains, valleys hidden beneath ice a sea-level threat
Mountain ranges and valleys hundreds of kilometres long have been sitting deep beneath Western Antarctica’s vast ice region, a discovery that scientists say could contribute to rising global sea levels.
A team of British researchers used ‘‘ice penetrating radar’’ to map the subglacial landscape, which they say adds a key piece of evidence to understand the frozen continent’s past, present and future behavior.
The researchers discovered three valleys linking Antarctica’s two major parts: the Western Antarctic Ice Sheet and the far bigger Eastern Antarctic Ice Sheet.
The newly discovered landforms prevent ice from East Antarctica from flowing through West Antarctica and to the coast.
But as ice sheets thin because of warming temperatures, these valleys and mountain ranges could ‘‘increase the speed and rate at which ice flows out from the center of Antarctica to its edges, leading to an increase in global sea levels,’’ said Kate Winter, the study’s lead author and a research fellow at Northumbria University.
‘‘Understanding how the East and West Antarctica ice sheets interact is fundamental to our understanding of past, present and future global sea level,’’ said Neil Ross, a senior lecturer at Newcastle University.
The biggest of the valleys, called Foundation Trough, is 350km long. Its width is more than 32km.
The other valley, called Patuxent Trough, is nearly 320km long and 14km wide. The smallest, the Offset Rift Basin, is 150km long and 30km.
The research was part of the European Space Agency’s Polargap project, an ambitious mission to collect data about the Earth’s global gravity field, and was published earlier this month in the Geophysical Research Letters journal.
Fausto Ferraccioli, principal investigator of the Polargap project, said the findings provide a significant window into the South Pole region, ‘‘one of the least understood frontiers in the whole of Antarctica’’.
‘‘These new Polargap data gives us both insights into how the landscape beneath the ice influences present ice flow, and a better understanding of how the parts of the great Antarctic ice sheets near the South Pole can, and cannot, evolve in response to glaciological change around their margins,’’ Ferraccioli said.
The discovery was a surprise to researchers.
Winter told NBC News that they had expected to find a mountainous region, but not the enormous size of the landforms.
Research has shown that Antarctica’s coastal glaciers, particularly in West Antarctica, are retreating at an alarming rate, raising concerns about the massive continent’s potential contribution to rising sea levels.
Last month, a new satellite survey revealed that 10 per cent of Antarctica’s coastal glaciers are moving at a significant speed back toward the center of the continent as they melt below, The Washington Post’s Chris Mooney reported. – Washington Post A truckers’ strike in Brazil left a patchwork of empty gas stations and barren supermarket shelves yesterday as drivers appeared unmoved by the government’s threats to use force or fine people who didn’t comply.
Police forces conducted operations to clear blocked roads and military vehicles provided escorts for trucks transporting emergency fuel to police stations and army facilities in Rio de Janeiro and Sao Paulo.