The Definitions - Article Example

Definitions Full Definitions Rain Shadow High mountains present resistance to rain clouds and prevent their movement by standing like a wall. Due to this phenomenon, the area on the other side of the mountain slope is deprived of rain. It is called rain shadow and the area suffers from the effects of dry air. Desertification Desertification involves conversion of fertile land into dry and barren area. This may be caused by lack of agriculture or a byproduct of drought. Deforestation is also a major cause and the effect gains magnitude with changing climatic conditions. The area gradually turns into a desert if vegetation is not sustained. The area can be revived by supply of water either by natural of artificial means. Dune A dune is a small mountain of sand. It can be created by the wind and its shape changes along with the direction and speed of the wind. Typically the surface facing the wind has a gradual slope. They are found mainly along coastlines, but are also present in dry areas inland. Inselberg An isolated hill present in a plain area. It is a result of resistance against weathering. The surrounding area, however, is affected by weathering and therefore the surface lowers gradually over time. An inselberg is a distinguished feature in an area and usually forms a plateau. Loess These are deposits of sand and clay joint together by wind over time (Wicander & Monroe, 2009, p.389). They usually present a vertical face towards the wind. Because of their composition they are weak structures and may erode easily. The mixture may also contain crystals found in sand. These accumulate over time and the surface can become porous. Desert Deserts are dry regions with extremely less supply of water. Water is lost by evaporation and the area usually suffers from low humidity levels. To distinguish deserts from dry regions a scale has been set. The area is termed desert if it receives less than 250 millimeters of annual rainfall (Ward, 2009, p.4). Monsoon With simultaneous heating of the land and the sea the water evaporates from the sea and this humid air is transported over land through a cycle. The warm air over land raises and develops a low pressure area. This is covered by the humid air or rain coming from the sea. The major characteristic of the Monsoon is the change in humidity level or the precipitation. Coriolis Effect An object flying in the atmosphere is affected by the Earth’s rotational movement. When an object is in the air the Earth changes its position relative to that particular object. Similarly due to this effect an object travelling in a straight line relative to the Earth will be moving in a curved path relative to any particular surface on the Earth. The effect implies specially to air travel and even long range missiles. Intertropical Convergence Zone The winds from the Northern and Southern hemispheres converge at the equator. Furthermore, the equator receives intense energy from the sun. The heated air rises vertically and is surrounded by the winds from the two hemispheres. As a result the equator usually has a circle of thin clouds formed by the three forces. Barrier Island An island extended in front of main coast acting as a barrier against sea waves. They may also be present in shape of chains of smaller islands. Their configuration depends on wave energies and variation in sea levels. They have inlets on both sides that leaves water passage to the main coast. Estuary An estuary is a combination of a coastal area along with rivers and streams making up fine inlets for the sea water. Fresh water from the rivers and streams is mixed with the sea water. The limits of an estuary are defined by presence of fresh water in that particular area. Longshore Current When sea current comes in contact with the coastline some of the current is rebounded. This current is usually at an oblique angle and depends on the direction of wind. This creates a current along the coastline which flows parallel to the shore. Neap Tide Tides depend on the position of the Sun and the Moon. During the first and third quarters of the Moon, the tides are at an average level. These tides are called Neap Tides. They are formed as a result of right angles between the Moon and the Sun which cancels some of the gravitational forces from both these bodies. Spit A portion of land may protrude outwards from the coastline. This may be a result of Longshore Currents. These protrusions are called spits. They can be found especially at corners of coastline. They are sometimes weak and made up of sand therefore; they may change direction over time. Spring Tide During the first and last quarter of the Moon; the Sun and the Moon are in same direction relative to the position of the Earth. This causes maximum gravitational pull from the two bodies and therefore, high tides. The effect is especially greater when the Moon is in first days of the first quarter or the last days of the fourth quarter. At this time the maximum magnitude of tides are known as Spring Tides. Tombolo Some of the islands are joined with the main land through a narrow strip of land or simply spits. This land has characteristics of spits and is usually sandy. They are not well formed but serve as a land connection between an island and the mainland. Emergent Coast The part of coast which is submerged in sea when comes out and exposed is called Emergent Coast. This may be due to number of reasons; however, fall in sea level is the most common. Alternatively, the coastline can rise due to tectonic activity resulting in submerged area being exposed. Embayment Embayment is simply a formation of a bay, but at a smaller scale. The sea water is enclosed or surrounded by land leaving one inlet. The term is typically used at a local level formation of bay along the coastline. Furthermore, the width of the inlet may be wider as compared to narrow features of a typical bay. Isostatic Rebound Glaciers cover wide land and exert huge downward force. The force is greater in glaciated areas, but when they retreat; their weight decreases on the land. With this release in pressure, the land rebounds or expands to its original position. This phenomenon is called Isostatic Rebound. Oil Trap The oil is usually found in natural containers. These containers trap the oil and prevent it from seeping. The surface is nonporous and prevents any escape whether vertical or lateral flow. The trap therefore forms a reservoir which naturally contains oil and makes it readily available for extraction. Ore An ore is a rock which contains minerals or even valuable metals in raw form. They may contain a mixture of minerals or metals and it is mined for extraction. The ore is the basic carrier of metals and minerals and these are extracted by industrial process separating the rock and the valuable content. Placer Deposit Heavier metals or minerals settle down through effect of gravity and they withstand forces of weathering due to their weight. These particles in a stream form a deposit and this deposit is filtered by the motion of the stream. Lighter particles are washed away by the force of the flow. Valuable minerals like gold or platinum are heavier and they form deposits at a lower bed of a stream. These can be called Placer Deposits. Non-Renewable Source These are natural resources which cannot sustain the consumption rate and are limited. They are consumed at a rate greater than they can be reproduced. They are therefore, limited and bound to finish at some stage. Fossil fuels are an example which is consumed at an astonishing rate and they are bound to be depleted in the future. Secondary Enrichment Mineral ores are weathered over time. Water is one of the major factors in weathering. The ores lose some of its valuable metals to the process. These minerals are carried with water in a solution state and are transferred to lower surfaces after seepage. The deposits settle down and mix with deposits in that particular surface layer, making those rich in valuable mineral content. Geothermal Energy It is the energy stored in the Earth. This energy mainly comes from the core of our planet. Energy is transferred to the surface from the core by conduction. This energy can be extracted and is a valuable energy harvesting source. Cap Rock These are surfaces made from hard rock which lay over a layer of soft surface. They are extremely rigid and resistant to weathering. The surface layer is nonporous and prevents damages from weathering to the lower surface. Diamond Pipes Diamonds are usually found in a strip like deposits. These formations are known as Diamond Pipes. They extend in a downward direction into the Earth. Carbon forms diamonds under pressure within these strips. They extend deep into the Earth and therefore, exert extreme pressure to its contents. Overthrust Belt Adjacent surfaces on different tectonic plates can come in contact with each other after movement these plates. The surfaces exert pressure against each other and in some cases the contents especially rocks are compressed and emerge. The process forms very distinguished belts and they are known as Overthrust Belts. Gypsum Gypsum is a salt rock which is water soluble to some extent. It changes its solubility with temperature. It is mostly present in crystallized form and deposits are found in sedimentary surfaces. It is a soft mineral and is easily broken; however, its crystals are not like sand since they dissolve in water over time. References Ward, D. (2009). The Biology of Deserts: Biology of Habitats. Oxford: Oxford University Press. Wicander, R., & Monroe, J. (2009). The Changing Earth: Exploring Geology and Evolution (5th ed.). Belmont, CA: Brooks/Cole. Read More