Geo Thinking

Facts of Interior of the Earth               The earth's radius is 6370 km. No one can reach the centre of the earth and make observation or collect samples of the materials. Under such conditions it is wonder to know how scientist tell us about the earth's interior and the type of materials that exist at such depths. Basically the sources of information about the interior of the earth are two types. These are- 1. Direct Sources, 2. Indirect Sources. The most easily available solid Earth material is surface Rock On The Rocks we get from mining areas. Gold mines in South Africa sdps 3-4 km. Going beyond this depth is not possible as it is very hot at such depths. Besides mining, scientists have taken up a number of projects to explore the conditions in the crystal portions. Scientist world over are working on two major projects such as deep ocean drilling project and integrated Ocean drilling project. The deepest drill at Kola in Arctic Ocean has so far reached at depth o

Plate tectonics  : The earth's crust is made up of several rigid and a solid plates. The term plate was first used by J. Tuzo Wilson, a Canadian geophysicist in 1965. Plate tectonic means the moment of plates. Classification of plates  : Plates can be classified into two groups, these are- 1. Major plates : a. Indian Plate, b. Pacific plate, c. American plate, d. African plate, e. Eurasian plate, f. Antarctica plate. 2. Minor plates : a, Arabian plate, b. Philippines plate, c. Cocos plate, d. Caribbean plate, e. Nazca plate, f. Scotia plate, g. Carolina plate, h. Juan de puca plate, I. Bismarck plate. Plate Margins : Plate margins or boundaries are most significant because all tectonic activity occur along the plate margins. Plate margins or boundaries are classified into three categories. These are- 1. Constructive or divergent plate boundary : divergent plate boundary in plate tectonic is a linear feature that exist between two plates that are moving away from

              A wide variety of landforms such as mountains, dissected plsteaus, flat plains, low lying Ocean basins, etc. exists on the earth surface. These landforms differ from each other in respect of their size, height, extent, etc., and yet all of them exist in a state of isostatic balance according to a definite law. There must be some unseen force behind creating such balance. It is known as isostasy. Isostasy :                     The word 'isostasy' has been derived from the Greek word 'iso-stasious' which means 'equal position'. In other words the gravitational adjustment of Earth's crust is isostasy, a state of balance. The term isostasy was first used by the famous American geophysicist C.E. Dutton According to him the doctrine of isostasy implies a position or condition of mechanical equilibrium under the control of of natural laws between the high mountain parts and low lying basins and oceanic parts over the rotating Earth. Var

DEFINATION:  The term geomorphology has been derived from three Greek words that is 'ge' 'Morphe' and 'logos' where Ge means earth, morphe  means form and logos means study. Thus geomorphology may be defined as the science or the study of various forms of Earth surface. It is the systematic and organised description and analysis of the landforms of the earth. The word landform has wide connotation and includes not merely the micro features of the land but also the major relief features such as continents, ocean basins, mountains, Plains etc. SCOPE AND NATURE: The subject matter of geomorphology may be organised on the basis 1. Dimension and scale of relief feature 2. Processes that shape the landforms, and 3. Approaches to the geomorphic study.  On the basis of dimension and scale,  features of the earth are classified into three categories- a. Relief features of the first order:  Relief features of the first order include Contin