Decoding!Glaciers!on!Topographic!Maps!Peaks!or!Horns!have!sharp!summit!peaks!erodedby3or!more!glaciers.!! Contours:!Aspot!height!with!three!or!more!cirques!surrounding!it.!!!!...

 Decoding  Glaciers  on  Topographic  Maps  

A hanging valley is a tributary valley left higher than the floor of the main valley. It is left 'hanging' above the main U-shaped valley. A waterfall can often be seen spilling over the edge.

Truncated spurs are formed when glaciers move through the main valley and cut off mountain spurs. They are often rounded at the top but steep at the bottom.

Contours: Look for a glacial trough with a small valley “hanging” above it, often with a waterfall.

   An  Arête  is  a  narrow  knife-­‐edged  ridge  or  divide  between  two  glacial  valleys.      Contours:  Between  two  cirques.  Contours  close  together  with  the  highest  land  in  the  middle.      

 Pyramidal  Peaks  or  Horns  have  sharp  summit  peaks  eroded  by  3  or  more  glaciers.      Contours:  A  spot  height  with  three  or  more  cirques  surrounding  it.    

U-­‐  shaped  valleys  are  distinctive  shaped  valleys  eroded  by  glaciation.  They  have  steep  sides  and  a  wide,  flat  floor.  They  are  formed  in  river  valleys  which,  during  the  ice  age,  have  been  filled  by  a  large  glacier.    

Contours:  Look  for  parallel  and  very  close  contour  lines.  The  valley  will  be  wide  with  few  contour  lines  and  often  contains  a  river.

 A  Corrie  or  Cirque  is  a  bowl-­‐like  depression  at  the  head  of  a  glacial  valley.  After  glaciation,  the  hollow  may  be  filled  by  a  small  lake  or  tarn.    Contours:  Look  for  horseshoe  contour  shapes  with  small  lakes  inside.