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.
Erosion by Valley Glaciers. Valley glaciers form several unique features through erosion. You can see some of them in Figure below and at this link: [Insert a link to a video that shows features eroded by valley glaciers.] As a valley glacier flows through a V-shaped river valley, it scrapes away the sides of the valley.