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.
Landslides and rock falls may be distributed over a wide area in earthquakes. larger than magnitude 6.0, but are typically within only a few miles of the earthquake. source in smaller earthquakes (magnitude 4.0-5.0). Rock falls are common during earthquakes and cause damage due to impact.