Fundamentals of Geography Essay

In geology, a stimulate is a of course occurring solid aggregate of star or more minerals or mineraloids. For utilization, the common rock, granite, is a combination of the quartz, felspar and biotite minerals. The earths outer solid layer, the lithosphere, is made of rock. Rocks allow been used by mankind by means ofout history. From the St single Age rocks have been used for tools. The minerals and metals we find in rocks have been essential to human civilization. 1 iii major groups of rocks ar defined flaming, sedimentary, and metamorphic.The scientific study of rocks is called petrology, which is an essential component of geology. At a gamey level, rocks argon composed of grains of minerals, which, in turn, atomic number 18 homogeneous solids formed from a chemical compound that is set up in an orderly manner. The aggregate minerals forming the rock be held together by chemical bonds. The types and abundance of minerals in a rock are determined by the manner in whic h the rock was formed. Many rocks bear silica (SiO2) a compound of silicon and oxygen that forms 74. 3% of the Earths crust.This material forms crystals with former(a) compounds in the rock. The proportion of silica in rocks and minerals is a major factor in determining their lift and properties. 2 Rocks are geologically classified according to characteristics such as mineral and chemical piece of music, permeability, the texture of the element particles, and particle size. These physical properties are the end resolvent of the processes that formed the rocks. 3 Over the course of time, rocks rat transform from one type into another, as described by the geological model called the rock cycle.These events produce lead general classes of rockigneous, sedimentary, and metamorphic. The ternary classes of rocks are subdivided into many groups. However, there are no hard and debased boundaries between allied rocks. By increase or settle in the proportions of their constituent mi nerals they pass by e real gradation into one another, the distinctive structures also of one kind of rock may oftentimes be traced gradually merging into those of another. Hence the definitions adopted in establishing rock nomenclature merely turn back to more or less arbitrary selected points in a continuously graduated series. 4 impassioned Igneous rock (derived from the Latin word igneus meaning of fire, from ignis meaning fire) forms through the chilling and solidification of magma or lava. This magma house be derived from partial melts of pre-existing rocks in all a planets mantle or crust. Typically, the melting of rocks is caused by one or more of three processes an increase in temperature, a decrease in rack, or a change in composition. Igneous rocks are divided into two chief(prenominal) categories plutonic rock and volcanic. Plutonic or intrusive rocks result when magma cools and crystallizesslowly within the Earths crust.A common caseful of this type is granite. Volcanic or extrusive rocks result from magma reaching the surface either aslava or fragmental ejecta, forming minerals such as pumice or basalt. 3 The chemical abundance and the rate of cooling of magma typically forms a sequence known as Bowens reaction series, after the Canadian petrologist Norman L. Bowen. Most major igneous rocks are found along this scale. 2 About 64. 7% of the Earths crust by volume consists of igneous rocks making it the most plentiful category. Of these, 66% are basalts and gabbros, 16% are granite, and 17% granodiorites and diorites.Only 0. 6% are syenites and 0. 3% peridotites and dunites. The oceanic crust is 99% basalt, which is an igneous rock of mafic composition. Granites and sympathetic rocks, known as meta-granitoids, form much of the continental crust. 5 Over 700 types of igneous rocks have been described, most of them having formed beneath the surface of Earths crust. These have diverse properties, depending on their composition and how they wer e formed. Sedimentary Sedimentary rocks are formed by sedimentation of particles at or near the Earths surface and within bodies of water.This process causes clasticsediments or organic particles (detritus) to settle and accumulate, or for minerals to chemically precipitous (evaporite) from a solution. The particulate matter and so undergoes compaction and cementation during diagenesis. Before macrocosm deposited, sediment was formed by weathering and erosion in a source area, and then transported to the place of deposition by water,wind, ice, mass presence or glaciers which are called agents of denudation. Mud rocks comprise 65% (mudstone, shale and siltstone) sandstones 20 to 25% and carbonate rocks 10 o 15% (limestone and dolostone). 3 About 7. 9% of the crust by volume is composed of sedimentary rocks, with 82% of those being shales, while the remainder consist of limestone (6%), sandstone and arkoses (12%). 5 Metamorphic Metamorphic rocks are formed by subjecting any rock ty pesedimentary rock, igneous rock or another older metamorphic rockto diametrictemperature and pressure conditions than those in which the original rock was formed. This process is called metamorphism meaning to change in form. The result is a profound change in physical properties and chemistry of the stone.The original rock, known as the protolith, transforms into other mineral types or else into other forms of the corresponding minerals, such as by recrystallization. 3 The temperatures and pressures required for this process are ever so naughtyer than those found at the Earths surface temperatures greater than 150 to 200 C and pressures of 1500 bars. 6 Metamorphic rocks compose 27. 4% of the crust by volume. 5 The three major classes of metamorphic rock are based upon the formation mechanism. An intrusion of magma that heats the surrounding rock causes contact metamorphisma temperature-dominated transformation.Pressure metamorphism occurs when sediments are bury deep under th e ground pressure is dominant and temperature plays a smaller role. This is termed burial metamorphism, and it can result in rocks such as jade. Where both heat and pressure play a role, the mechanism is termed percentageal metamorphism. This is typically found in mountain-building regions. 2 Depending on the structure, metamorphic rocks are divided into two general categories. Those that accept a texture are referred to as foliated the remainder are termed non-foliated. The name of the rock is then determined based on the types of minerals present.Schists are foliated rocks that are primarily composed of lamellar minerals such as micas. A gneiss has visible bands of differing lightness, with a common example being the granite gneiss. Other varieties of foliated rock include slates, phyllites, and mylonite. Familiar examples of non-foliated metamorphic rocks include marble,soapstone, and serpentine. This branch contains quartzitea metamorphosed form of sandstoneand hornfels. 2 In geography stages are one of the most important tools researchers, cartographers, students and others can use to examine the entire Earth or a excessised part of it.Simply defined occasions are pictures of the Earths surface. They can be general lineament and show landforms, political boundaries, water, the locations of cities, or in the case of thematic parts, show different but very peculiar(prenominal) topics such as the sightly rainfall distribution for an area or the distribution of a certain disease throughout a county. Today with the increased use of GIS, also known as Geographic Information Systems, thematic maps are growing in importance. There are even so applications for different types of general reference maps when the different types are understood correctly.These maps do not tho show a citys location for example instead the different map types can show a plethora of information about places around the world. The following is a list of each major map type use d by geographers and a description of what they are and an example of each kind. Political routine A political map does not show any topographic features. It instead focuses solely on the pronounce and national boundaries of a place. They also include the locations of cities both large and small, depending on the detail of the map. A common type of political map would be one demonstrate the 50 U.S. states and their borders along with the join States north and south international borders (map of the United States). Physical Map A physical map is one that shows the physical landscape features of a place. They generally show things like mountains, rivers and lakes and water is always shown with blue. Mountains and extremum changes are usually shown with different colors and shades to show relief. Normally on physical maps green shows dishonor elevations while browns show high elevations. An example of a physical map is one presentation the state of Hawaii (map of Hawaii).Low elevation coastal regions are shown in dark green, while the higher elevations modulation from orange to dark brown. Rivers are shown in blue. Topographic Map A topographic map is similar to a physical map in that it shows different physical landscape features. They are different however because they use contour lines instead of colors to show changes in the landscape. Contour lines on topographic maps are normally spaced at regular intervals to show elevation changes (e. g. each line represents a one C foot (30 m) elevation change) and when lines are close together the terrain is steep.For example a topographic map showing the Big Island of Hawaii would have contour lines that are close together near the steep, high elevation mountains of Mauna Loa and Kilauea (map of the Big Island). By contrast, the low elevation, flat coastal areas show contour lines that are spread apart. clime Map A humour map shows information about the climate of an area. They can show things like the specific climatic zones of an area based on the temperature, the amount of snow an area receives or average number of cloudy old age. These maps normally use colors to show different climatic areas.A climate map for Australia for example uses colors to show differences between the temperate area of Victoria and desert region in the center of the continent. Economic or Resource Map An economic or resource map shows the specific type of economic natural action or natural resources present in an area through the use of different symbols or colors depending on what is being shown on the map. For example an economic activity map for Brazil can use colors to show different agricultural products of given areas, letter for natural resources and symbols for different industries (image showing a map of Brazil). Road Map A road map is one of the most widely used map types.These maps show major and minor highways and roadstead (depending on detail) as well as things like airports, city locat ions and points of interest like parks, campgrounds and monuments. Major highways on a road map are generally red and larger than other roads, while minor roads are a lighter color and a narrower line. A road map of San Francisco, California for example would show the major highways as a wide red line and other large roads as a lighter red with minor streets as gray (map of San Francisco). Thematic Map A thematic map is a map that focuses on a particular theme or special topic and they are different from the six aforementioned general reference maps because they do not just show natural features like rivers, cities, political subdivisions, elevation and highways. If these items are on a thematic map, they are background information and are used as reference points to enhance the maps theme. An example of a thematic map would be one showing the population change of Canada in specific locations from 1996 to 2001.The map shows the theme it is attempting to get across to its audience an d uses a political map (e. g. one showing the provincial and territorial borders of Canada) to give it more of a reference. What Is the Difference Between put up and Climate? Its a sweltering midsummer day. It must be planetary warming, mutters someone. But is it the Earths ever- changing climate that has made the day so warm? Or, is it just the weather that is so unbearable? Weather is the mix of events that happen each day in our atmosphere including temperature, rainfall and humidity. Weather is not the same everywhere.Perhaps it is hot, dry and sunny today where you live, but in other parts of the world it is cloudy, fall or even snowing. Everyday, weather events are recorded and predicted by meteorologists worldwide. Climate in your place on the globe controls the weather where you live. Climate is the average weather pattern in a place oer many years. So, the climate of Antarctica is quite different than the climate of a equatorial island. Hot summer days are quite typical of climates in many regions of the world, even without the effects of global warming. Climates are changing because our Earth is warming, according to the research of scientists.Does this contribute to a warm summer day? It may, however global climate change is actually much more complicated than that because a change in the temperature can cause changes in other weather elements such as clouds or precipitation. Atmospheric circulation is the large-scale deed of air, and the means (together with the smaller ocean circulation) by whichthermal energy is distributed on the surface of the Earth. The large-scale structure of the atmospherical circulation varies from year to year, but the basic climatological structure remains fairly constant.Individual weather systems mid-latitude depressions, or tropical convective mobile phones occur randomly, and it is accepted that weather cannot be predicted beyond a fairly short point of accumulation perhaps a month in theory, or (currently) about ten days in cause (see Chaos theory and Butterfly effect). Nonetheless, as the climate is the average of these systems and patterns where and when they tend to occur once more and again it is stable over longer periods of time. As a rule, the cells of Earths atmosphere shift polewards in warmer climates (e. g. nterglacials compared to glacials), but remain largely constant even due to continental drift they are, fundamentally, a property of the Earths size, rotation rate, heating and atmospheric depth, all of which change little. Tectonic hullabaloo can significantly alter major elements of it, however for example the jet stream -, and plate plate tectonic theory shift ocean currents. In the extremely hot climates of the Mesozoic, indications of a third desert belt at the Equator has been found it was perhaps caused by convection. But even then, the overall latitudinal pattern of Earths climate was not much different from the one today.The wind belts girdling the planet are organised into three cells the Hadley cell, the Ferrel cell, and the Polar cell. Contrary to the impression given in the simplified diagram, the vast bulk of the vertical bowel movement occurs in the Hadley cell the explanations of the other two cells are complex. Note that there is one discrete Hadley cell that may split, shift and merge in a complicated process over timecitation needed. Low and high pressures on earths surface are balanced by opposite relative pressures in the upper troposphere.