Antarctica what is under the ice

This region is also home to a huge canyon system , which extends all the way from the ice sheet interior to the coast. The system is as deep as the Grand Canyon but km longer. So far our tour has focused on the central regions of Antarctica, where ice and water are relatively stable. Many of these have subglacial lakes in their catchments. Tens to hundreds of kilometres in length, these lakes are short-lived, growing and draining over a period of just a few years.

Evidence of this drainage process comes from satellite measurements of the height of the ice sheet. The surface can be seen to rise and fall, as the lake swells and then ebbs away again. More are being found every year. This flow, in turn, can change the currents in the Southern Ocean and potentially affect ocean circulation worldwide. Related: Photos of Antarctica: The ice-covered bottom of the world. The lakes sit at the bottom of the ice sheet, where the ice meets the rocky Antarctic continent.

Unlike in Greenland , where meltwater flows from the ice surface through crevasses and holes called moulins, Antarctica's lakes form from beneath the ice, probably as a result of pressure, friction and perhaps geothermal heat. In , Scripps Institution of Oceanography glaciologist Helen Amanda Fricker connected the elevation changes measured by ICESat to the dynamics of the lakes deep beneath the ice surface.

As the lakes drain and fill, the ice above rises and falls, offering hints as to what's happening below. Fricker's breakthrough opened up the possibility of tracking the lake system over time. We were able to keep the hole liquid long enough to make detailed ocean measurements as well as leave instruments behind to continue monitoring ocean currents and temperature. These data are still coming in via satellite. The hundreds of metres of ice isolate the ocean cavity from the furious winds and freezing air temperatures of Antarctica.

But nothing stops the tides. Our data suggest tides push the stratified ocean back and forth past undulations on the underside of the ice and mix parts of the ocean cavity. Read more: How solar heat drives rapid melting of parts of Antarctica's largest ice shelf.

This sort of discovery is the ultimate challenge for climate science. How do we represent processes that work at daily scales in models that make projections over centuries?

Our data show the daily changes can add up, so finding a solution matters. The lack of landmass under West Antarctica makes the region more vulnerable to melting, as it lacks the mountain ridges that stabilize the glaciers in the east. Satellite data collected between and showed that the thinning of the ice shelves floating sheets of ice that connect to a landmass stagnated in East Antarctica, while in West Antarctica, the rate of the melting tripled.

In , NASA created the most detailed map of the continent yet. By combining ice movement measurements, seismic data and radar images, the map — dubbed BedMachine Antarctica — revealed previously unknown topographical features, such as the broad ridges that protect the glaciers flowing across the Transantarctic Mountains, which divide East and West Antarctica.

That's far deeper than the Dead Sea, the lowest exposed region of land, which sits 1, feet below sea level. The map is an important resource that will help scientists predict precisely which regions of ice are at greatest risk of sliding into the ocean in the coming decades and centuries, and which sections might be more stable than expected. Despite major progress in the mapping of subglacial geology, significant sections of Antarctica remain unresolved and important spatial details are missing.

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