Glaciers- Modifiers of the Landscape

In her lecture on Thursday, June 5th, at the Valdez Museum, Suzanne McCarthy defined a glacier as "a long lasting mass of ice, formed on land, which moves under its own weight." According to her, there are three major kind of glaciers- Valley Glaciers, Piedmont Glaciers, and Ice Sheets. Glaciers are formed when more snow falls in the winter than can melt in the summer. The snow builds up, forms layers, which shrink together, compact, press out the air, and form ice. There are many glaciers in our area, most of which are receeding. They have, in large part, formed the terraine we see every day, and indeed are still impacting it. Some formations that glaciers leave behind are Horns, Aretes, Eradics, and Ogives. Sugarloaf is a nice big example of a Horn, which we see every clear day.
I am glad I had the chance to learn about glaciers from Suzanne. She has a good way of translating technical knowledge into everyday terms. For example, she talked about when glaciers dam off lakes, and then suddenly release and flood, just like when you have ice in your glass and add water to it, the ice suddenly will lift up and start to float as you fill the glass. This happens to Hidden Lake in McCarthy every mid-summer. Wouldn't it be neat if we got to see it happen while we're there? From far away, in a safe place, of course.