Salient features of world’s physical geography

Earth is splendid terrestrial haven. It is imperative to know physical geography through its display of environmental diversity. In scientific studies, it is established that Geography is a word that originated from two Greek roots. Geo-denotes to “Earth,” and graphy stands for “picture or writing.” Geography is the study of earth as the home of present day human being (Sagmit, 1998).The main objective of geography is the assessment, and explanation of Earth, its variability from place to place, the way places and features transform over time, and the processes responsible for these variations and changes. Geography is termed as the spatial science because it incorporates recognizing, analysing, and explaining the variations, similarities, or differences in phenomena situated on the surface of Earth. Geography is unique among the sciences by virtue of its characterization and central purpose. It describes the values and attitudes towards environment and sharpen intellectual and practice skill.

Earth’s structure is divided into three zones that include crust, Mantle and core. Crust is the solid outer layer of the Earth, and its depth is usually never more than 1 per cent of the Earth’s radius, or averaging 40–50 km, but this varies significantly around the sphere. These are two different types: oceanic and continental. Mantle is the region within the Earth’s interior that range from 25 to 70 km below the surface, to a depth of ~2,900 km. It is composed mainly of silicate rocks, rich in iron and magnesium. At the base of the mantle, temperatures may reach up to 5,000°C. These high temperatures may help to generate convection currents which drive plate tectonics. Core is the very centre of the Earth and is composed of iron and nickel. It consists of an outer core (semi-molten) and inner core (solid). The temperature at the very centre of the Earth (~6,300 km below surface) may reach 5,500°C.

Geography is inherently encompassing discipline. It brings together facts from other sciences such as physical biological and social. Physical geography is related to the physical science. Physical geography includes the processes and attributes that constitute Earth which incorporate human activities where they interface with the atmosphere. Different branches of Physical geography are climatology, Meteorology, Geomorphology and pedageography (Sagmit, 1998).Scientific studies have revealed that physical geographers are more interested in comprehending all aspects of Earth and can be considered generalists because they are qualified to scrutinize a natural environment in its entirety, and how it functions as a unit. In physical geography, researchers study about lithosphere, atmosphere, hydrosphere, and biosphere. Due to interaction of these elements, numerous changes occur on earth surface. Most physical geographers concentrate on advanced study in one or two specialties. For instance, meteorologists and climatologists believe how the interaction of atmospheric components influences weather and climate. Meteorologists focus their studies learning the atmospheric processes that affect daily weather, and they use current data to predict weather conditions. Climatologists are interested in the averages and extremes of long-term weather data, regional classification of climates, monitoring and understanding climatic change and climatic hazard, and the long term impact of atmospheric conditions on human actions and the surroundings.

The factors involved in landform development are as varied as the environments on Earth, and include gravity, running water, stresses in the Earth’s crust, flowing ice in glaciers, volcanic activity, and the erosion or deposition of Earth’s surface materials. Biogeographers scrutinize natural and human-modified environments and the ecological processes that influence their characteristics and distributions, including vegetation change over time. They also research and explain the ranges and patterns of vegetation and animal species, seeking to find out the environmental factors that limit or facilitate their distributions. Several soil scientists are geographers, who are concerned in mapping and analysing soil types, determining the aptness of soils for certain uses, such as agriculture, and working to conserve soil as a natural resource. Geographers are broadly concerned to study water bodies and their processes, movements, impact, quality, and other features. They may serve as hydrologists, oceanographers, or glaciologists. Many geographers involved with water studies also function as water resource managers, who work to ensure that lakes, watersheds, springs, and groundwater sources are suitable to meet human or environmental needs, provide an adequate water supply, and are as free of pollution as possible. Hydrology is merging science. It helps to understand the processes in which water plays an important role in nature through oceans, rivers and glaciers in sustaining life forms of earth surface.