The deadly dynamics of landslides

Chemical reactions between the muds and the salt in the seawater strengthened the muds a process rather like the setting of freshly poured, watery cement. Later, after the weight of the glaciers had been removed, Scandinavia rebounded upward, elevating these cemented muds as much as 600 feet above sea level. During the Rissa slide, fine-grained materials flowed down a gentle slope. At the other extreme, some landslides consist mainly of huge rocks that roar down steep slopes. The small village of Elm sits below a mountain in an area of Switzerland where slate a rock that fractures nicely to expose flat surfaces that make great blackboards was quarried with explosives for decades. The introduction of mandatory public education in the mid-19th century greatly increased the quarrying activities.