Glaciers advanced from Canada and retreated four or more times. Over a few million years, Puget Sound was carved and scoured by glaciers. Heavy Pressure. Glaciers containing up to 2,383 cubic miles of ice pushed over the Puget lowland.
AM stands for amplitude modulation, while FM stands for frequency modulation. In AM, the amplitude (the height or depth of the crests or troughs) changes, while in FM, the fre â¦ quency changes. Answered.
AM Radio broadcasting is the oldest technology to feature them. Naturally, they are part of the black body radiation spectrum from just about every object in space. For objects as cold as the cosmic microwave background, and as part of the cosmic microwave background itself, radio waves are the dominant emission.