Sand boil
= Sand boil
{wiki=Sand_boil}
A sand boil, also known as a sand boil-out or sand vent, is a geological phenomenon that occurs during a flooding event or when groundwater pressure is high. It happens when water forces its way to the surface through a layer of sand or other loose sediment. Typically, this occurs when water saturates the soil, causing increased pore pressure that cannot be supported by the overlying material.