Is The Ground in Denali Really
Frozen Solid Just Inches
Below The Soil?
This is an image of exposed
(image from http://dana.ucc.nau.edu/~nlb5/)
Denali is full of
lush green plants.
National Park’s Visitor Center, we spoke to the Park Ranger,
Ingrid. She told us
that Denali Park receives very little rain. On average, Denali only gets about 14 inches of rain, about
the same amount of rain that the desert area of Arizona gets.
How can it be that Denali gets so little rain but is so
full of lush green plants and has such abundant animal life?
The answer lies in the
permanently frozen layer of ice that lies beneath much of Denali
National Park. This
layer of ice is called permafrost.
In some areas of Denali, the permafrost is only 8 inches
below the surface of the Tundra. While in other areas, the top of
the permafrost layer can be as deep as 11 feet.
Permafrost can be extremely thin, 1mm, or very thick, ¼
mile deep. Look over here. At this river bank,
you can see the very top of the permafrost where soil has eroded
This is an Image of Wet
Tundra in Denali
This layer of permafrost is impermeable to water.
The permafrost traps all water near the surface of the
earth. As the warm
summer sun melts some of the permafrost, the ice melts to water
and is trapped
on top of the remaining permafrost. As
the summer rains fall on Denali, the water soaks into the tundra
but cannot penetrate the permafrost.
The rainwater is trapped on
top of the ice.
The trapped melted ice and rain provide the water for the lush
green plants and animals of the arctic tundra.
So, You Want To Learn More About Alaska's
ground in the Arctic
This (Hands-On Fun)