ALASKA GLACIERS

Mendenhall Glacier, outside Juneau.

One of many glaciers in Glacier Bay

College Fjord

Glacial ice appears blue because of its crystalline structure. Once it has been exposed to the atmoshpere for a few days, it turns white.

There are actually three glaciers that join together here before falling into the sea. The dark streaks in the center of the glacier are rock that glaciers have scoured from the granite mountains during their journey.

This glacier was nearly 150 feet tall (above the sea) and another 100 feet below the surface. Note the fractures in the ice as it cracks and falls into the sea.

This glacier was about 1.5 miles wide and over 250 feet above sea level.

Notice the striations of ground rock imbedded in the glacier. I always thought of a glacier as pure and clean ice. This is not necessarily true.

It is hard to describe the enormity of the mountains. To give some idea of the scale, this was a tour boat with a capacity of aobut 50 persons. It was dwarfed by the granite mountians coming down to the sea.

On our flight back home, we flew over several glaciers. From about 30,000 feet you see where two glaciers join from ice fileds up in the mountains and then the combined glacier falls into the sea.

Again, the confluence of two glaciers from 30,000 feet.

When we first saw the glaciers, the guides talked about how muck they have melted in the last 50 years. Many have retreated 10 or more miles since about 1950. At first, this seemed to confirm man's impact on the global warming process. Then later, learned more of the history of Glacier Bay. In 1794, this area was explored by George Vancouver, and surveys of the area noted amere indentation "terminated by solid compact mountains of ice." John Muir visitied the area several times between 1879 and 1899. The glaciers had retreated some 30 miles between 1794 and 1892. (REFERENCE) (MAP)

Now, I wonder about the cause of global warming. This certainly seems to be proof that it began before the industrial revolution. What could have been the cause back then? Can we stop it now? Questions which I doubt will be answered in my lifetime.