changing earth

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earth movements Earth movements are divided on the basis of the forces which causes them. The forces which act on the interior of the earth are called ENDOGENIC FORCES, And the forces which act on the surface (exterior) are called EXOGENIC FORCES. Endogenic forces Earthquakes Volcano's landslides Exogenic forces River Wind Sea waves Glaciers

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A seismograph records the pattern of waves on a revolving drum of paper. These wavy lines show the strength of the various seismic waves and the times at which they occur. The tracing is called a seismogram. The study of earthquakes is called seismology The seismograph is basically a heavy pendulum with a stylus, or needle, suspended above or in front of a revolving drum. During an earthquake the pendulum and needle remain stable while the drum on the base moves, recording the wave patterns. Seismographs of exactly the same character are deployed at stations around the world to record signals from earthquakes and underground nuclear explosions. The World Wide Standard Seismograph Network incorporates some 125 stations. Measuring Earthquake

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The strength of an earthquake may be measured either by the amount of damage done or by instrument readings. The Modified Mercalli Intensity Scale is commonly used by seismologists to determine the amount of destruction caused by an earthquake, it defines 12 levels of earthquake strength The Richter Magnitude Scale grades earthquakes on 1 to 10 scale. It is based upon the amount of energy released by the rock movements rather than upon surface damage. Measuring Earthquakes Waves

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Of the many attempts to find clues for predicting the location, time, and strength of future earthquakes, the best results seem to be associated with seismicity studies using earthquake observatories. Chinese researchers, however, have achieved some success using, in part, signs of animal restlessness for forewarning. Other methods are based on detecting gaps in the seismic record of a region. Segments along a fault where displacement has not taken place for a long time are more likely to release built-up stresses.

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EARTHQUAKE PREPARDNESS Individuals should learn to protect themselves during An earthquake……. 1. Do not panic, stay calm. 2. If you are indoors, don't rush outside. Move under doorways, tables or beds. 3. Keep away from windows, mirrors and things that could fall. 4. If you are outdoors, move to a open space, away from buildings,trees,electrical wires and poles. 5. In your home, keep heavy objects away from bed and arrange them in a manner that they don’t obstruct passages. 6. Shut off gas and electricity, for this may lead to fire. 7. Have earthquake preparedness drills.

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Erosion, removal of sediment, rock, and soil from the landscape, resulting in the formation of new landforms and the lowering of the land surface, This process of erosion and deposition create different landforms on the surface of the earth. Weathering, breakdown of rocks by physical and chemical processes at the surface of the Earth’s crust. It is the initial stage in the denudation (lowering of the land surface) of landscape, which produces debris known as regolith. This can subsequently be transported away by such agents of erosion as running water, ice, the wind, or the sea, and eventually deposited.

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angel falls(venezuela)

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niagara falls(north america)

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victoria falls(africa)

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Sea waves continuously strike at the rocks, over time they become larger and wider this hollow like structures formed in the rocks are called SEA CAVES

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As the caves become bigger and bigger due to continuous erosion only the roof of the caves remain thus forming SEA ARCHES.

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Further erosion breaks the roof and only the walls are left, these wall like features are called STACKS

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The steep rocky coast rising almost vertically above sea water is called SEA CLIFF.

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Sea waves deposits sediments along the shores forming sea beaches

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Glacier,  moving mass of ice formed in high mountains or in high latitudes where the rate of snowfall is greater than the melting rate of snow. Glaciers can be divided into four well-defined types—alpine, piedmont, ice cap, and continental—according to the topography and climate of the region in which the glacier was formed.

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While the glaciers travels downwards it carve out deep hollows, and as the ice melts they get filled up with water and becomes beautiful lakes.

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The material carried by the glacier such as rocks, sand and silt get deposited on the sides of the glaciers, these deposits are then called as glacial moraines.

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mertz glacier(antartica)

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When the wind blows, it lifts and transports sand from one place to another, and when the wind stops blowing the sand falls and gets deposited in low hill like structures --- called SAND DUNES

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When materials finer than sand are carried by the wind and finally dropped to the ground, the deposit that results is known as loess. Thick layers of loess are found in Europe and the Americas, and loess deposits of Asia reach a thickness of several hundred meters. They are the basis for some of the richest agricultural soils of the world.