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.
For a list of stations authorized to transmit both analog and digital signals, use the following links instead of the AM Query: [ AM | FM ] AM Query search FM Query search TV Query search For more information on AM and FM radio broadcasting, please visit the Audio Division website, and the Broadcast Radio Links page. For more information on Television broadcasting, please visit the Video Division website.