meaning of this

Hello, Dear teachers:

I would like to know what is the meaning of this sentences.Specially the last one.

'California,as we all know, is a land prone to earthquakes, in which the ground splits asunder beneath one's feet and one is likely to lose one's bearings.'

Gracias.(thanks)

ana

[Tdol]

California has many earthquakes, the ground can break up under your feet and that can make you lose your sense of direction