what is glacial advance and glacial retreat?

Question

please describe the processes the best you can

Answer 1

A glacial advance is when the surface of the ice in the North and South pole grows, more water in the surrounding oceans is frozen, so they grow and advance southward to the tropics. The glacial retreat is when the excess of ice to the tropics melts, and the extension of the poles returns to normal, or the area that it's covered since it's been measured.

Answer 2

The fronts of glaciers advance and retreat in response to the amount of snowfall at their sources and the temperature at the distal end (the front, toe, or foot of the glacier).

The WAY the retreat works is interesting, however. Even though the position of the toe of the glacier moves toward it's source, the ICE in the glacier continues to move forward. Think of a butcher pushing a long bologna into a slicer. The end of the bologna stays put, but the meat itself still advances into the slicer. If the butcher begins to move the slicer back (so the position of the end of the bologna retreats) meat is STILL being pushed forward.

The way ice moves is still under study. It certainly slides on the bottom some, and there are other modes, such as melting/recrystallization, and ice crystal deformation. The whole glacier acts like an extremely viscous fluid (on a large scale).

Answer 3

It's basically what it is, glacial advance is where water that doesn't melt help form more of a already formed glacier, advancing it in size. A glacial retreat is when it starts to melt beyond the boundaries it once was extended to.

Answer 4

Glacial adavnces when more snow builds up than melts, Retreat is when it melts faster than it builds up thus retreating