Forces working within the earth’s surface are called endogenic forces.
Endogenic forces are the pressure within the earth, also known as internal forces. Such internal forces contribute to vertical and horizontal motions and lead to subsidence, land upliftment, volcanism, faulting, folding, earthquakes, etc.
Sudden geomorphic movements occur mostly at the lithospheric plate margins (tectonic plate margins).The plate margins are highly unstable regions due to pressure created by pushing and pulling of magma in the mantle (convectional currents).These movements cause considerable deformation over a short period of time.
Volcanism and Earthquakes are caused as a result of sudden movements due to earth’s endogenic forces.