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 is an abbreviation of the Latin words ante meridiem  meaning before noon. It is used to designate the time from midnight  to noon.    It is also used in radio commâ¦unication to mean Amplitude  Modulation   A.M. is an acronym for the Latin term, Anti Meridian, (Before  Noon).