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 was the undisputed king of the airwaves in 1952, but that didnât stop Blaupunkt from introducing the first in-car FM radio. 1953: Becker Mexico Introduced. Beckerâs iconic Mexico radio launched this year, arguably the first premium in-car radio. It had AM/FM and the first fully automatic station-search button. 1955: First âMusic On Demandâ. Starting in 1955, Chrysler offered a small turntable in its high-end cars, playing proprietary seven-inch records with about 45 minutes of music. It was a bust.