Antarctic - Ancient Landscape Discovered Beneath The East Antarctic Ice Sheet
Of particular interest to Astrobiology mission planners are the ice-covered worlds in our solar system – Enceladus, Europa, Ganymede, Mimas, Titan, etc. and the probability that they have vast oceans beneath their surfaces. As we seek to penetrate the outer surface, what sorts of geology will we find underneath? Studies in Earth’s polar region can help us develop the tools to study these icy worlds from space, on their surfaces, and one day, beneath their outer surfaces.
Understanding the graphic image: A Surface elevation of the Antarctic Ice Sheet from the Reference Elevation Model of Antarctica68. The black line marks the present-day grounding line74; pale areas are floating ice shelves. b Bed elevation of Antarctica beneath the grounded ice sheet from BedMachine v.364. Surface and bed elevations are relative to the global mean sea level (the EIGEN-6C4 geoid). The black dashed box shows the extent of the maps in Figs. 2 and 5, and lines of latitude are separated by 5°. ASB Aurora Subglacial Basin, DML Dronning Maud Land, GSM Gamburtsev Subglacial Mountains, TAM Transantarctic Mountains, WSB Wilkes Subglacial Basin. c Composite global oxygen isotope record from benthic foraminifera75. Lower (more negative) δ18O values indicate lower ice volume and/or warmer ocean temperatures; higher (more positive) δ18O values indicate greater ice volume and/or cooler ocean temperatures. Labels show the timings of major climate intervals or transitions (red), glacial expansions (black), and prevailing glacial conditions (blue). Plio. = Pliocene; Plt. = Pleistocene; note that the Holocene epoch (0.012–0 Ma) is not shown on the timescale. — Science
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We’re part of an international research team that has discovered an ancient landscape that has lain hidden beneath the East Antarctic Ice Sheet for millions of years.
The researchers, led by Durham and Newcastle universities, used satellite data and radio-echo sounding techniques to map a 32,000 km2 area of land underneath the vast ice sheet.
They discovered a landscape that appears to have been formed by rivers at least 14 million years ago and possibly even before the initial growth of the East Antarctic ice around 34 million years ago.
This newly discovered landscape consists of ancient valleys and ridges, similar in size-and-scale to the glacially-modified landscape of North Wales, UK.
It tells us important information about the early, and long-term, history of the East Antarctic Ice Sheet, as well as helping us to understand how it might evolve in response to future climate change.
The discovery builds on previous work by this team who, in collaboration with other researchers, have mapped out hidden mountain ranges, canyon systems and lakes beneath the ice in Antarctica.
Although the landscape beneath the ice sheet is not visible to the naked eye, satellite images captured over the region show small undulations of the ice sheet’s surface that provide clues about what lies beneath.
In a few places, the landscape’s existence has been confirmed by using radio-echo sounding from planes to see through the ice and map the shape of the land beneath the ice sheet.
The research team proposes it is likely that there will be other, as yet undiscovered, ancient landscapes hidden beneath the East Antarctic Ice Sheet.
Their study has been published in the journal Nature Communications.
Top images show the plane and equipment used to conduct a partial survey of Antarctica during the ICECAP data gathering project, courtesy of ICECAP. Central image shows how the landscape of Antarctica would appear if the ice were lifted away, courtesy of Stewart Jamieson.
