A rockfall or rock-fall[1] is a quantity/sheets of rock that has fallen freely from a cliff face. The term is also used for collapse of rock from roof or walls of mine or quarry workings. "A rockfall is a fragment of rock (a block) detached by sliding, toppling, or falling, that falls along a vertical or sub-vertical cliff, proceeds down slope by bouncing and flying along ballistic trajectories or by rolling on talus or debris slopes."[2]
Alternatively, a "rockfall is the natural downward motion of a detached block or series of blocks with a small volume involving free falling, bouncing, rolling, and sliding". The mode of failure differs[how?] from that of a rockslide.[1]
- ^ a b Whittow, John (1984). Dictionary of Physical Geography. London: Penguin, 1984. ISBN 0-14-051094-X.
- ^ Varnes, D.J., 1978, Chapter 2, Slope Movement Types and Processes