The Atacama Desert *Open up to Biodiversity Notes* “The Driest Place on Earth”

Deserts

Choose the words that best describe a desert Humid Arid Dry Cold Oasis Hot Freezing Wet Muggy Chilly

Atacama Quick Fact World's driest coastal desert; 0.04" (10 mm) precipitation; most of it from coastal condensation (fog). https://app.discoveryeducation.com/learn/videos/3AD64DD9-43F9-4D41-9527-27FC4CFDD845?hasLocalHost=false Start at 14:18 end at 18:00

Major Deserts of the World

What is a Desert? Receives very little precipitation Types of Deserts Less than 10 inches per year Types of Deserts Hot and Dry Semiarid Coastal Cold

Cold Deserts These deserts are characterized by cold winters with snowfall and high overall rainfall throughout the winter and occasionally over the summer. They occur in the Antarctic, Greenland and the Arctic realm. They have short, moist, and moderately warm summers with fairly long, cold winters. The mean winter temperature is between -2 to 4° C and the mean summer temperature is between 21-26° C.

How was this land shaped? What processes formed the shapes that you see on the wall?

Changes in the Landscape

Changes in striations caused by fault movements

Sand Dunes

Flash Floods The Atacama is referred to as “the driest place on Earth” Some parts of the Atacama have not received even a drop of rain since record keeping has begun. However, when it does get rain it usually comes all at once. This forms flash floods in the areas down hill.

Chilean Flash Flood March 2015 https://www.youtube.com/watch?v=s73N09syaTU

What are the short and long term impacts of flooding of this magnitude? Alluvial Fan- dry sediment deposits left behind after flooding

Why are Deserts hotter than areas along the Equator? Sand and rock heat up much more rapidly than water, and they also lose heat more quickly. As the sun climbs higher in the sky, the dry ground heats much faster than water, and much faster than the ground would if it were wet. On a hot summer day in the Sahara, sand and rock can heat up to 170o F

What Causes a Desert? Rainshadow- shown here, the mountain range forces the air coming off of the coast upward causing it to condense and fall as precipitation on the “Windward” side. Leaving the “Leeward” side dry.

Tibetan Plateau

Proximity to Large Bodies of Water Most water in atmosphere is evaporated from the sea, and this water eventually precipitates on land. Land closer to the sea generally receives much of this moisture.