What is Geomorphology?? What are the Characteristic of geomorphology ?
DEFINATION:
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 Continental platforms and ocean basins (including Continental margins).
b. Relief features of the second order:
Relief features of the second order are superimposed on the continents and oceans basins and include plains,plateaues and mountains on the continental surface, mid oceanic ridges oceanic plains, trenches on the ocean floor.
c. Relief features of the third order:
Relief features of the third order are listen features which mainly develop on the relief features of the second order. Valleys Canyons, waterfalls, beaches etc are some examples of relief features of the third order.
The subject matter of geomorphology may also be organised on the basis of geomorphic processes both endogenetic and exogenetic that shape the landforms and approaches to the study of landforms.
Approaches to geomorphological analysis are
1. Historical approach :
Historical approach of landform studies involves description of landform evolution through successive stages of geological time.
2. Quantitative and empirical approach:
Quantitative or empirical approach as alternative to historical approach is adopted to explain landform characteristics of such larger area where sufficient evidences for historical study are not available because of destruction of of relic forms due to Greater degree of dissection by subsequent geomorphological processes.
EXOGENETIC FORCE
The exogenetic forces or processes also called as denudational processes or destruction forces or processes are originated from the atmosphere. These forces are continuously engaged in the the destruction of the relief features created by the endogenetic forces through there weathering erosional and depositional activities. Exogenetic processes are, therefore, planation processes. Denudation includes both weathering and erosion where weathering being a static process includes the disintegration and decomposition of rocks in situ whereas erosion is dynamic process which includes both removal of materials and their transportation to different destinations. Weathering is basically of three types viz. (a) Physical or mechanical weathering, (b) Chemical weathering and (c) Biological weathering. Weathering is very important for the biospheric ecosystem because weathering of parent rocks results in the formation of soils which are very essential for the sustenance of the biotic lives in the biosphere. The Erosional processes include running water or river, groundwater, sea waves, glaciers, periglacial processes and wind. The Erosional processes erode the rocks, trsnsport the eroded materials and deposit them in suitable places and thus form several types of Erosional and depositional landforms of different magnitudes and dimensions.
