The McMurdo Dry Valleys form the largest ice-free area on the Antarctic continent and one of the most extreme deserts on the planet. This area recieves less than 10cm of precipitation per year (in the form of snow), and experiences katabatic winds up to 200mph rushing down the valley. There are no larger terrestrial plants in the area, although there are certain types of smaller organisms including lichen, mosses, diatoms, algae, and nematodes (microscopic worms) that survive near the region's seasonally ice-covered lakes.
The Dry Valleys are part of the Transantarctic mountain range that spans across Antarctica, separating the East and West Antarctic Ice Sheets. Since Antarctica is in the Southern hemisphere, its seasons are opposite to those in the Northern hemisphere, and temperatures in the Valleys range from as cold as -90F (-68C) in July winter, to up to record highs of 50F (10C), with an average of 10-25 days per year above freezing. This creates an unusual situation during the summer when warmer temperatures cause glaciers in the area to melt and water flows through the desert for 1-2 months. The meltwater streams are called ephemeral because they are only present during part of the year.
Graduate students measure streamflow in Taylor Valley during austral summer
Scientists in this region study a number of projects from the seasonal glacial melt and the organisms living in streams to the formation of Don Juan Pond, the saltiest body of water in the world, and there are even researchers using the extreme environment of the Dry Valleys to help understand if there may be life on Mars. The Dry Valleys share a lot of environmental characteristics with Mars because both have polar ice caps, valleys, rivers, lakes, and similar temperatures in the coldest months. Since water flows and disappears annually in the Dry Valleys leaving microorganisms behind in the sediment to survive the long winter, researchers are studying the extremophiles (organisms capable of living in extreme coditions) in the Dry Valleys to learn if it may be possible to find similar life on Mars.
Find out more about research projects in the Dry Valleys through articles on recent discoveries here and a description of projects and scientific themes here, read the blog of a graduate student describing life in the field here, or watch additional videos below.
Video link: Hassan Basagic describes the unique characteristics of glaciers in the Dry Valleys from the field. (via exploratorium.edu)
Video: During a videocast from McMurdo Station in Antarctica, graduate student Alex Mass answers the question 'Why is there 24 hour daylight in Antarctic summer?' (via thelastdegrees.wordpress.com)
Video: Geobeats News describes the unusual "Blood Falls" melt out of Taylor Glacier in the Dry Valleys.
Video: Scientist Diane McKnight, author of The Lost Seal, gives a 1 hour comprehensive lecture about floods, drought, and ecosystem change in the McMurdo Dry Valleys in this UNAVCO Science Seminar.