HOLY EARTH TITS!!!! WHAT IS THIS?
Soil liquefaction describes a phenomenon whereby a saturated or partially saturated soil substantially loses strength and stiffness in response to an applied stress, usually earthquake shaking or other sudden change in stress condition, causing it to behave like a liquid. The phenomenon is most often observed in saturated, loose low density or uncompacted sand type soils.
AKA: A poor mans trampoline.