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.
This is in contrast to AM radio where the signal is used to modulate the amplitude of the carrier. The FM band of the electromagnetic spectrum is between 88 MHz and 108 MHz and the carrier waves for individual stations are separated by 200 kHz for a maximum of 100 stations.