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.
When you listen to a radio station and the announcer says, You are listening to 91.5 FM WRKX The Rock!, what the announcer means is that you are listening to a radio station broadcasting an FM radio signal at a frequency of 91.5 megahertz, with FCC-assigned call letters of WRKX.his band of the radio spectrum is used for no other purpose but FM radio broadcasts. In the same way, AM radio is confined to a band from 535 kilohertz to 1,700 kilohertz (kilo meaning thousands, so 535,000 to 1,700,000 cycles per second).