The quick clay that is widespread in many parts of western Sweden has the property that it can very easily go from solid to almost runny if it is disturbed by, for example, piling in connection with the construction of houses.
The quick clay that has been mapped in Sweden is mainly found along the western Swedish coastline and the areas around the water, areas that were once below sea level.
Tobias Thorén, who is a geotechnician at the Swedish Geotechnical Institute, says that they are constantly working to prevent these landslides, but that it can be very difficult to predict where and when they may occur.
- Ground inspections and investigations are done on new construction in this area, but if and when a landslide can occur and thus disturb the quick clay is difficult to predict, he says.
Parallels to Norway
According to the preliminary reports from experts in Norway, the Norwegian landslide took place in clay, ie the same kind of clay that is found in western Sweden.
And the latest major landslide that occurred in the West was in Lökeberg, between Marstrand and Kungälv in 2019, where several buildings were destroyed.
- There was a large area that began to move, and in some places the ground level changed by over 10 meters, says Tobias Thorén.
Hear him tell you more about the quick clay in the clip above.