To me, the highlight of our visit to Glacier Bay National Park was the Margerie Glacier. The Margerie Glacier is a wall of ice about 250 feet tall and about a mile wide. Large chunks of this glacier are constantly “calving” or breaking off. Our ship pulled up alongside the glacier and we were able to watch many pieces calve.
First you hear a large “CRAAAACK” eminating from somewhere on the glacier. Seconds later you will see a chunk of ice, sometimes large, sometimes small, fall from the glacier into the water. As the ice hits the water it sends out a wave, based on the mass of the ice. These waves are usually quite small, but on one occassion we witnessed a chunk of ice which was the full height of the glacier, and about 250 feet in width calve off from the front face. When it hit the water the wave was massive. The captain quickly turned the ship about so that the wave would hit us head-on and not from the side.
When the pieces of ice hit the water they start to roll. This comes about because they break up from a alarge piece of ice into smaller ones. As this happens the center of gravity of the new smaller pieces shifts, causing them to roll.
We sat and watched the glacier calve for a couple of hours. It was amazing to see. This was the highlight of the trip for me.