Plunge pool softer or fractured rock has been eroded back to a knickpoint, water continues to bombard its base. Because this rock is often less resistant than overlying strata, the water from the higher elevation continues eroding downward until an equilibrium is achieved. A somewhat similar bowl-shaped feature developed by flowing water, as opposed to falling water, is known as a scour hole. These occur both naturally and as a result of bridge building. Plunge pool A plunge pool (or plunge basin or waterfall lake) is a deep depression in a stream bed at the base of a waterfall or shut-in. It
Escape chute Escape chute An escape chute is a special kind of emergency exit, used where conventional fire escape stairways are impractical. The chute is a fabric (or occasionally metal) tube installed near a special exit on an upper floor or roof of a building, or a tall structure. During use, the chute is deployed, and may be secured at the bottom by a fire fighting crew some distance out from the building. Once the tube is ready, escapees enter the tube and slide down to a lower level or the ground level. Although some early escape tubes were made entirely of