A surgical mask is used inside the operating room or during other sterile procedure areas to protect the patient environment from contamination. Surgical masks have ties so that they can be adjusted for fit, and are tied over the top of a surgical or bouffant cap.
rockfall. 1  an act or instance of the falling of rock, as in a cave-in or an avalanche. 2  a mass of rocks that have fallen: to be trapped under a rockfall.
A rock slides is the rapid sliding of a mass of bedrock along an inclined surface of weakness, such as a bedding plane, a major fracture int eh rock or a foliation plane. A rock avalanche is a very rapidly moving turbulent mass of broken up bedrock. Flowage on a grand scale.