| Alaska, 1979 | |
[1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20]
The Disco glided close to the glacier. Glacier Bay may look placid, but its waters rise and fall some 7 meters with the tide. Also, a layer of fresh water can lie on top of the seawater and mask some wave action. The line in the water marks a boundary between fresh and salt, or perhaps the edge of a wave of tidal water. In any case, the risk rises the nearer we get to the glacier. A large berg falling off—a process called calving—can send waves into the ship. If we were doing something delicate like turning or raising a small boat from the water, the ship's rocking could cause injuries.
As it happens, a party of scientists set off in a small boat toward the face of the glacier. I don't remember what they did, but we never took our eyes off them until they were safely back aboard.
Johns Hopkins Glacier, close up. It's a combination of five large ice streams, accounting for the dark stripes of sediment, or medial moraines. Each forms where two glaciers join, their lateral moraines combining. Glacier ice is technically a metamorphic rock, and its peculiar blue color helps fix that impression. Photos don't really do it justice.
