A small iceberg floats in an Alaskan glacial fjord, accompanied by smaller pieces of ice. The stark coldness of the scene was accented visually under foggy and overcast skies, the water tinged with fine silt. Yes, the black spots are supposed to be there. Each consists of clumps of ground-up rock and muddy ice, entrained into the glacier as it scoured its way down the valley to the sea. As the ice melts, this material is freed, falling to the bottom of the fjord. When glacial ice melts on land, the same process leaves behind moraines. In water, it combines with finer silt to slowly fill the fjord with sediment, such that over many millennia, the arm of the sea will become a delta valley bracketed by mountains.
College Fjord AK (28 Jul 3) , looking down and NNE