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 ranges from 535 to 1705kHz (kilohertz, or thousands of cycles per-second of electromagnetic energy). These are the numbers you see on your AM radio dial. N ote in the tan area at the left of the illustration below that AM radio waves are of a lower frequency than either FM radio or TV waves.Thus, as we will see, after being transmitted, they will behave differently. S tations can theoretically be placed every 10KHz, along the AM band. ote in the tan area at the left of the illustration below that AM radio waves are of a lower frequency than either FM radio or TV waves. Thus, as we will see, after being transmitted, they will behave differently. S tations can theoretically be placed every 10KHz, along the AM band.