You are hiking in the mountains and find some snow and ice. You drill a hole in the snow and ice to the bottom but not into the materials beneath. Later, you come back and meausure the shape of the hole, and find that there has been no change. Based on the definition of a glacier, you should conclude:

A) The snow and ice you found are a glacier, because glaciers do not have deformation.
B) The snow and ice you found are not a glacier, because glaciers must have deformation in the ice.
C) You cannot tell whether the snow and ice is a glacier, because you did not measure whether there is any sliding of the ice over materials beneath.
D) You cannot tell whether the snow and ice is a glacier, because you did not measure whether there is any Pepsi beneath, and all glaciers slide on Pepsi.
E) The snow and ice you found must be called a glacier, because all snow and ice are in glaciers

An important characteristic of glaciers is that they move. This is why they are sometimes likened to "rivers of ice." This movement is called glacial motion. There are four main types of ways in which glaciers move. The first one is basal sliding, which occurs when the entire glacier slides over its bed. The second one are glacial quakes. These generate fractional movements of large sections of ice. The third one is bed deformation, which is limited to some areas of sliding. Finally, the fourth one is internal deformation, which happens when the weight of the ice causes the deformation of ice crystals.