McMurdo Dry Valleys Facts
- First of all, the region collectively known as the McMurdo Dry Valleys easily ranks as one of the most extreme deserts known to man. This remains especially remarkable given one particular fact. That holds true because the incredible feature formed in a section of the continent of Antarctica.
- However, even in this extremely inhospitable environment, Nature finds a way to adapt. Certain types of photosynthetic bacteria inhabit the comparatively damp interiors of rocks in the area. Further, incredible bacteria with metabolisms based entirely on sulfur and iron appear to thrive under a local glacier.
- The magnificent location includes numerous geological features to amaze the rare explorer. These include more than a dozen separate valleys and eleven recognized glaciers. In addition, due to a rather high saline content, liquid water flows in parts of the area. This amazing combination of factors allows a total of eight meltwater streams to form, as well as twelve small lakes.
McMurdo Dry Valleys Geology
Firstly, the stunning McMurdo Dry Valleys formed in conjunction with what geologists call the Beacon Supergroup. This formed during a period from 400 – 250 million years ago. Further, the region also cuts through sections of even older rock formations, largely consisting of various types of granite.
Relatively large quantities of unsorted glacial sediment, known as tills, also cover the exposed areas of bedrock. But, these deposits, in themselves fascinating, appear in widely scattered pockets. These largely differ in composition from tills found in other parts of the world. Most others remain rich in mud.
This rather sharp contrast occurs as a result of the unique nature of their origin. In this location, the tills deposited from extremely cold-based ice. Similar deposits in other regions, however, formed as primarily moist-based. Finally, as a result of these factors, large amount of loose gravel also dot the landscape of the region.
McMurdo Dry Valleys Location and Climate
The marvelous McMurdo Dry Valleys reside in one of the southernmost regions of the Southern Hemisphere. More specifically, the formation sits within the region known as Victoria Land. This geological wonder also sits roughly due west of the stunning site known as McMurdo Sound.
In addition, the austerely beautiful region has a total area of roughly 1,900 sq mi (4,800 sq km). This accounts for a respectable 0.03% of the total area of the entire continent. It also, unsurprisingly, represents the largest ice-free region of the entire continent of Antarctica.
The fascinating section of the world derives its name from its remarkable climate. That’s because, despite its location, it remains one of the most arid places on the planet. This extreme lack of humidity contributes to, but does not solely account for, the lack of any permanent accumulations of snow or ice.
The tiny average precipitation of only 100 mm per year occurs also occurs due to the relatively great height of the surrounding mountains. These features, in themselves awesome, serve to prevent the advance of the local ice sheet. This fact plays another part in the nature of the valleys.
Yet, the extreme winds in the region, known as katabatic winds, also play a pivotal role in its aridity. These powerful, relatively warm winds, often achieve speeds of 200 mph (320 kph). These powerful natural winds, therefore, serve to rapidly evaporate any deposited ice or snow.