Updated By: LatestGKGS Desk
Isostasy: Airy and Holmes Theory, geographical views, physical reactions
What is Isostasy and how it affects Earth's surface?
The views of Arthur Holmes on isostasy, to a greater extent, are compatible with the views of Airy. Following Airy Holmes has also assumed that upstanding crustal parts are made of lighter materials and in order to balance them major portions of these higher columns are submerged in greater depth of lighter materials (of very low density).
According to Holmes, the higher columns are standing because of the fact that there is lighter material below them for greater depth whereas there is lighter material below the smaller columns up to the lesser depth.
Holmes and D.L. Holmes (1978) have tried to explain and illustrate the concept of isostasy through a diagram (fig. 6.9) which ‘shows characteristic examples of crustal columns, each of which has the same area and extends downward to the same depth below sea level, the same depth at which the weight of each column exerts approximately the same pressure on the underlying material, irrespective of its surface elevation.
They have taken the depth of 50 km for isostatic compensation in those areas which have not been disturbed by geological events for the fairly long duration. A. Holmes and D.L. Holmes have attempted to explain and illustrate the concept of equal weight along the ‘level of equal pressure’ through the examples of 4 columns of equal cross-section through characteristic parts of the continents and ocean floor.
