In this lesson we are going to learn about the causes of Earth Movements
Causes of Earth Movements (a) Magma movement within the earth’s crust. (b) Gravitational force (c) Convectional currents in the mantle (d) Isostatic adjustment 1. Magma Movement within the Earth’s Crust• When magma moves with force pushing crustal rocks horizontally or vertically.• When magma moves from reservoir and leaves empty spaces onto which crustal rocks are pulled inwards. 2. Gravitational Force - When the attractive force of the earth pulls crustal rocks into empty spaces left after magma escaping from the reservoir3. Convectional Currents within Mantle- When convectional currents in magma in mantle drug crustal rocks by friction. Horizontal movement of currents cause horizontal movements while vertical cause vertical movements. 4. Isostatic Adjustment -Rising of continental masses to restore the upset state of balance between sial and sima layers. -Isostacy is the state of balance between sial and sima layers. It can be disturbed by erosion on continents and melting of continental ice sheets. -The reduced weight causes continental masses to rise.