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 Landslide is a type of mass movement that occurs when a thin block of soil, rock, and debris separates from the underlying bedrock. Actually, this thin block of soil and rocks were held by Tree's roots so it do not separated from the bedrock.