Mass Movements: Landforms Shaped Under the Force of Gravity

Abstract

“A heavyweight for Einstein – Probing gravity where no one has done it before”. This was the headline of a press release in April 2013 by the Max Planck Institute for Radio Astronomy (Bonn, Germany). John Antoniadis, a student of the institution and his colleagues put Einstein’s general theory of relativity to the test in a cosmic laboratory 7,000 light years from Earth, where two exotic stars – a pulsar or neutron star and a white-dwarf – are circling each other. Einstein’s theory states that objects with mass cause a curvature in space-time, which we perceive as gravity. And the scientists’ results matched Einstein’s prediction perfectly even in the most extreme conditions tested yet. It is almost impossible to imagine that the gravity on the pulsar’s surface is 300 billion times greater than the gravity on Earth. From all four universal forces of nature, gravity is the weakest one and equates 9.81 m/s² close to the surface. You can overcome it easily for example if you drop an iron nail on the floor and pick it up with a small bar magnet from a child’s toy. But gaze out of the window: Gravity is shaping the landscape everywhere around us when it exceeds the cohesive strength of slope materials and friction and as a consequence downslope movements of masses of soil, sediments or rocks occur. Collectively they are termed mass movements. The downslope movement can be very slow and almost imperceptible or very sudden and catastrophic when massive landslides leave a path of destruction in their wake. This chapter shows examples of different mass wasting processes and landforms.