Tønsberg | Norway

In Nordic countries, so-called quick clays play an important role regarding safe building settlements, especially for essential infrastructure. Originally deposited in a marine or brackish environment, quick clay formations composed of silt and clay are exposed to fresh water due to the isostatic uplift above sea level after deglaciation. This caused leaching to low salinity, which may destabilise the formation, up to a sudden liquefaction collapse. The detection of safe building ground, e.g. bedrock, and the knowledge of the internal soil structure above it is therefore essential in areas prone to quick clay deposits.