Tuesday, May 3, 2011


Glaciers are found in Patagonia near the Andes Mountains.   

Along with bringing in tourism to Argentina, the glaciers provide water
for drinking and irrigation for the communities that live nearby. 

Despite global warming, Argentina's Perito Moreno glacier is
one of the few icefields that has withstood rising global temperatures. 


Glaciers form in the accumulation zone and begin to move across the surface by 
internal deformation and basal slip. In the ablation zone, glacial ice is 
lost due to calving, melting, and sublimation. 

Figure 1. The video below shows glacial ice calving from the "Perito Moreno Glacier."

U-shaped valleys are formed from erosion as the glacier ice moves through the floor of the valley, smoothing and plucking rocks. Aretes are knife-like ridges that can usually be seen on the sides of a glacial trough.

Figure 2. This picture shows a U-shaped valley in Argentina formed by a glacier. 

 Figure 3.  Drumlins are seen running parallel to each other in Patagonia
after being formed by bed deformation beneath the ice sheet.

Figure 4.  Many kettle lakes can be found in the outwash plains of Patagonia.

Figure 5.  Kettle lakes are formed when a block 
of buried glacial ice in the outwash plains melts


When till (mixture of boulders, gravel, sand and clay) is left behind in the ablation zone by the glacier, moraines are built on the sides and middle of the glacier. 

Figure 6. Several people hike the lateral moraine of Perito Moreno Glacier.  

When accumulation of ice is equal to ablation, 
the front is stable and a terminal moraine is built.  

Figure 7. This picture shows a terminal moraine of "Perito Moreno" 
along with many glacial crevasses.


 As a glacier melts, streams form in front and deposit outwash.

Figure 8.  This alluvium is carried by meltwater streams far into the outwash plains.  

As a result of glaciers, fluvial landscapes surround the Andes Mountains. 
As a meandering river's amplitude increases, deposition occurs on 
the inside of the river bend while the outside cut banks are eroded. Overtime 
as the erosion continues on the outside of the river bend, the river shifts course. 

Figure 9.  Taken from space with remote sensing, the Rio Negro in Argentina 
demonstrates alterations of the meandering channel within its floodplain. 


Works Cited