Cause of earthquakes

Earthquakes are caused due to disequilibrium in any part of the crust of the earth. A number of caused have been assigned to cause disequilibrium in the earth's crust such as volcanic eruptions, faulting and folding, up warping and down warping, hydrostatic pressure of man-made water bodies like reservoirs and lakes, and late the plate movements. The occurrence of severe devastating earthquake of San Fransisco (U.S.A) in 1960 led H.F. Reid, one of the official investigators of San Fransisco Earthquake Disaster, to advance his important ELASTIC REBOUNB THEORY to explain the mode and causes of earthquake mainly caused by fractures and faults in the earth's crust and upper mantle. Recently, PLATE TECTONIC THEORY has been accepted as the most plausible explanation of earthquakes.

Natural hazards

Natural environmental hazards and disasters involve comparatively rare high-intensity processes and extreme events caused by both terrestrial and atmospheric processes. The study of natural hazards includes the consideration of identification of specific events, finding of their causative factors, assessment of their impacts on human and other biological communities, prediction of such events and finding their remedial measures. Natural hazards fall in two broad categories (1) planetary hazards and (2) extra-planetary hazards or extra-terrestrial natural hazards.

Aspect and approaches to environmental management

On an average environmental management involves (1) judicious and gainful utilization of natural resources for socio-economic development and (2) Maintenance of environmental quality by perusing ecological principle. Broader objectives of environmental management include (i) to restrict and regulate the exploitation and utilization of natural resources, mainly non-renewable natural resources; (ii) to regenerate degraded environment and to renew natural resources (iii) to control environmental degradation and pollution (iv) to reduce the impacts of extreme events and natural disaster (v) to make optimum utilization of natural resources by recycling and reusing waste materials produced from one activity to another economically and environmentally viable activity (vi) to review and revise the existing technologies of production in terms of their adverse effects on the environment (vii) to formulate laws and regulations for the implementation of environment protection and conservation programs to maintain the environment quality.