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.
Cirque glaciers form on the crests and slopes of mountains. A glacier that fills a valley is called a valley glacier, or alternatively an alpine glacier or mountain glacier. A large body of glacial ice astride a mountain, mountain range, or volcano is termed an ice cap or ice field.