He is thought to have been crossing a snow bridge - a drift giving the illusion of a solid surface - when it collapsed.
The Sun (2013)
It's good enough to use as a desktop speaker, but it can cause quite a vibration on a solid surface.
Times, Sunday Times (2015)
There will be no bed as we know it, because the slightest downward movement against a solid surface produces an upward impetus.
Times, Sunday Times (2007)