1 Prepare before your flight by getting a doctor's letter or note on a prescription pad, stating that you have an implanted metal object. Show this letter to security agents.  Tissue expanders will be overfilled, so your skin can stretch and drape when your permanent breast implant is placed.
If valley glaciers erode a mountain from several directions, a sharpened peak called a horn might form.
The bottom half of a glacier behaves like a plastic while the top is brittle. Crevasses or cracks on the surface forms as a glacier descend down a mountain. Glacier types. There are two types of glaciers: Alpine glaciers-glaciers that occupy mountain valleys. Continental glaciers-glaciers that occupy land masses. Depending on the type of glaciers, they leave behind characteristic erosional features. Glacier or U-shaped valleys-glaciers carve out existing valleys and leave behind U-shaped valleys. www.geology.wisc.edu. Cirques-half bowl shaped hollow that is located high or at the head of the glacier.