A Place on Earth Where It Hasn't Rained or Snowed for 2,000,000 Years

Antarctica

Click here for "What is Antarctica?"

Dry Valleys, Antarctica. Image credit: NASA

From "The Driest Place on Earth" by Universe Today

The driest place on Earth is in Antarctica in an area called the Dry Valleys, which have seen no rain for nearly 2 million years. There is absolutely no precipitation (snow or rain) in this region and it makes up a 4,800 square kilometer region of almost no water, ice or snow. Water features include Lake Vida, Lake Vanda, Lake Bonney and the Onyx River. 

There is no net gain of water (the amount of water does not increase). The reason why this region receives no precipitation is because of Katabatic winds, winds from the mountains that are so heavy with moisture that gravity pulls those winds down and away from the Valleys.

One feature of interest is Lake Bonney, a saline (salt) lake situated in the Dry Valleys. It is permanently covered with 3 to 5 meters of ice. Scientists have found mummified (dried and frozen) bodies of seals around the lake. Lake Vanda, also in the region, is 3 times saltier than the ocean. Temperatures at the bottom of this lake are as warm as 25 degrees Celsius.

The Dry Valleys are one of the most extreme desert climates anywhere on earth, a cold desert where the mean annual temperature is between -14C and -30C depending on the site -- windier sites are less cold. An area of the world is called a desert if it has little rain or snowfall. Deserts can be hot (like the Sahara) or cold (like the Antarctic).

(Mean annual temperature - The mean is the average of the numbers and is calculated by dividing the sum of the numbers by the total number of numbers. For example: the mean of 5, 10, 15 is the numbers added up (30) and then divided by the number of numbers (3), so the mean is 10.) 

Knowing the difference between "mean" and "median" (the middle number in a series of numbers) can be very useful. - Derek) 

 Click here for more about mean and median with examples

Bull Pass, above, in the Dry Valleys. The temperature in the ice and snow-free area is little or no different to the adjacent ice-covered regions, the local geography accounts for the absence of ice.

The next driest place in the world measured by the amount of precipitation that falls is the Atacama Desert in Chile and Peru. There are no glaciers that are feeding water to this area; and thus, very little life can survive. Some weather stations in this region have received no rain for years, while another station reports an average of one millimeter per year.