Geology And Geophysics

Facts about the Mcmurdo Dry Valleys of Antarctica

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Antarctica is covered by a 1.6 kilometer (1 mile) deep sheet of ice, but not quite all of it. The McMurdo Dry Valleys form an unusual region, resembling the surface of Mars. The ice-free valleys stand out with striking contrast to the surrounding ice and snow, encompassing 98% of the continent. 

The McMurdo Dry Valleys can be found on the western coast of the McMurdo Sound and cover approximately 4,800 square kilometers (2982.6 square miles) of iceless terrain. In the valleys are lakes that perennially ice over, streams, and exposed soil as well as bedrock. The area suffers from extremely low temperatures, low precipitation, and high salt accumulation. Despite the extreme conditions, the valleys are home to a substantial amount of life, constantly being examined by scientists. Throughout the year, between 1,000 and 3,000 scientists live at the McMurdo Station where they study the area. Numerous discoveries have been made in and around the valleys from the scientific hub. The station is actually a small city build on volcanic rock and is the southernmost point accessible by ship. 

Despite the lack of ice in the McMurdo Dry Valleys, they are far from pleasant. Highly unique, as well as harsh, conditions are what keep the ice at bay. Katabatic winds, or winds moving with downward motion, caused by gravity can reach up to 322 kph (200 mph) in the valleys. As the winds rush toward the ground they heat up and evaporate any moisture they come in contact with. The mountains surrounding the area are high, preventing the sheet of ice from penetrating the region. The terrain consists mainly of bedrock with the occasional ice wedge and formation dotting the landscape.

One of the most notable, and scientifically significant, landmarks of the McMurdo Dry Valleys are the Blood Falls. The deep red colored waterfall is five-stories tall and flows from the Taylor Glacier. It was discovered in 1911, and its strange color comes from a subterranean body of water. There are microbes that were trapped in the underwater lake, locked in ice causing them to evolve separately from the rest of the world with no light, oxygen, and very little heat. They are essentially primordial ooze. The water in which they were trapped is high in iron and salt. The iron is what gives the waterfall its color. A fissure in the glacier has allowed the trapped water to leak out, but has not disturbed the bizarre ecosystem inside, which proves that life can exist in the most harsh of environments. 

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