Endogenic Forces — Folding, Faulting, Earthquakes And Volcanism

Endogenic Forces — An Overview

Endogenic forces are the forces that are created inside the earth and are responsible for creation of some relief features along with some phenomenon like folding, faulting, earthquakes and volcanism. Thus these forces are also known as internal forces. These forces are an integral part of the overall earth movements . The forces or movements responsible for the formation of relief features and changes occurring in them are known as earth movements or Geomorphic Processes. These forces are divided into two broad categories.

• Endogenic forces which cause land upliftment, subsidence, folding, faulting, earthquakes, volcanism etc.
• Exoganic forces which cause destruction of relief features through their Weathering, Erosional and Depositional activities.

Endogenetic Forces (Movements)

The forces coming from within the earth and causing horizontal and vertical movements are known as Endogenetic forces. It is these movements which lead to land upliftment and subsidence, folding and faulting, earthquakes and volcanism, etc. Endogenic forces are responsible for giving birth to major relief features such as mountains, plateaus, plains , valleys , etc. These endogenic forces fall into two major categories, on the basis of intensity:

1. Sudden movements: Sudden movement results in sudden and rapid events such as earthquakes and volcanic eruptions. It must be noted that these events are the result of a long-period of preparation deep within the earth. Only their effects in the form of earthquakes and volcanic eruptions are experienced as sudden events. These are also termed as constructive movements as they produce certain relief features such as volcanic mountains and lava plateaus ( e.g. Deccan )

2. Orogenetic movements: These movements are caused by the endogenic forces working in a horizontal manner and they involve folding, bending, faulting , and thrusting. These endogenic forces are also known as tangential forces. They are of two types :

• Compressional movement (convergent movement): When Orogenetic or horizontal forces operate face to face. They cause folding of the rock strata on the earth.
• Tensional movement (Divergent Movement): When horizontal forces operate in opposite directions. They produce cracks, fractures and faults in the crustal parts of the earth. Read More