Physics Photo of the Week

February 11, 2011

Glaciated and Non-glaciated Appalachians

The top photo was taken from the top of Mt. Pisgah in Northern Vermont overlooking Willoughby Lake.  Note that the neighboring mountains are all round-topped - the rounded appearance is caused by many thousands of years of glaciation.  The glaciers helped form Willoughby Lake - a very deep lake of ancient volcanic origin.  The volcanic activity occured about 400 million years ago.  The last glaciers receded relatively recently - only 10 thousand years ago.

The bottom photo was taken from another Mt. Pisgah looking south.  This Mt. Pisgah is in North Carolina near Asheville and Warren Wilson College.  Notice that the Southern Appalachians consist of V-type valleys, and the peaks are "sharp" and jagged.  The Southern Appalachians have never been glaciated, hence they have not been rounded.  There are also no natural lakes in the area.  Glaciers tend to form lakes due to many moraines and deposits that form natural dams to create lakes.

Both these areas of the Appalachian Mountains are moderately rugged and support a large variety of plant and animal life.

Physics Photo of the Week is published weekly during the academic year on Fridays by the Warren Wilson College Physics Department.  These photos feature interesting phenomena in the world around us.  Students, faculty, and others are invited to submit digital (or film) photographs for publication and explanation.  Atmospheric phenomena are especially welcome.  Please send any photos to 

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