Here's a breakdown:
* What happens: Individual rocks or boulders detach from a cliff face or slope and fall freely under gravity.
* Causes:
* Weathering: Freeze-thaw cycles, rain, and wind can weaken rock and create fractures.
* Earthquakes: Seismic vibrations can dislodge rocks.
* Slope instability: Over-steepened slopes, especially those with weak rock or soil, are prone to rockfall.
* Human activity: Construction, blasting, and road building can trigger rockfalls.
* Impact:
* Damage to infrastructure: Roads, buildings, and power lines can be damaged or destroyed.
* Injuries and fatalities: Rockfalls can cause serious injuries or even death.
* Landslide potential: Rockfalls can trigger larger landslides.
* Mitigation:
* Rockfall barriers: Walls, fences, and nets can be installed to catch falling rocks.
* Slope stabilization: Techniques like bolting, grouting, and rockfall protection can be used to make slopes more stable.
* Early warning systems: Sensors can detect rock movement and alert authorities.
In simple terms, imagine a steep mountainside. A piece of rock might become loose due to rain, freeze-thaw, or an earthquake. Then, gravity takes over, and the rock tumbles down the slope, creating a rockfall!
