Geological science : subjects and methods


Experimental science has had great development during two resent centuries and it brought many results which can be seen all of them around us and use them every day. We are used to these results as we can not feel them anymore. Look at your around, how many artificial tools can you find that are result of this sciences?


Geological science : subjects and methods Experimental science has had great development during two resent centuries and it brought many results which can be seen all of them around us and use them every day.   We are used  to these results as we can not feel them anymore. Look at your around, how many artificial tools can you find that are result of this sciences? In old times, a scientist knew almost all of sciences of his era, but nowadays due to spread of domain of scientific findings, it is not possible that one person can enter to all of science fields. As a result of that various fields has been created in science and the scientists study in one or several scientific fields in terms of his interests. In experimental science there are various fields too. Due to subject of study of all of them is nature, these fields have near relations to each other. Method  If we regard experimental science result of a work which has been done by scientists we should see what these people do. The scientists are following of nature secrets, but they think more about “what” or “how” rather than “why”, So the science has two dimension: 1-      Set of produced sciences 2-      The method which is used for gaining of those sciences It is interesting that these obtained sciences are not absolute history of science is full of example about rejection of old thoughts and replacing them by new ideas. So we can say that sometimes way of getting to realities has more importance than realities by itself. After many experiments errors and during time is created for solution of scientific problems as a interesting and use full methods that main stages are found as follow: 1) observation (gathering data from sensor lambs ) -gathering of sciences was begun since human pay attention precisely  to its environment .the building which you can finds image in next page, was made over 3500 years ago in England island . For a long time no one knew its reason but in recent years it becomes oblivions that its builders were astronomists who studied Precisely movement of moon , sun and stars by help of this building .the studies which were carried out whit computer recently, indicated that this Observatory was been helped to  its builder to learn about beginning of seasons and probably time of eclipse. In spite of all scientist used of such suitable observatory , they probably didn’t know that the earth moves in similar to moon , sun and stars .they believed sun rises really in the sky and rotate around the earth. but it was that the sun  rises in specified day between two stones from beginning of summer each year, then it in kinds a bit more than last day southward and then it was inclined northwards a little in next summer and in beginning of next summer it reached to first place of primary stone. The buildings which primitive people have built is a evidence for this claim that they regard to their observations. 2)measurment (determination of quantities and various vary able of phenomena and objects) Its necessary to experimental after observation which need to measurement in geology works just likes many of other fields of experimental science. Basically investigation an come up experiment after question which cannot been answer only by observation .more presided iteration and using of suitable  tools and scales is what it is important . 3) explaining   (Locating of result altogether in order to gaining patterns and relations) When we find relations between results by means of existed evidences and available information and reasons of process Serving is very important in geology science , because we can find out to past only by this method or we can inform from type of sun very slow process (erosion and etc,….).now take a look to shape of sand dunes in next page. When you say which photo is taken before another one , with a mention of several reasons ,you you can explain the scene. Background information is necessary. 4) Making Hypothesis making hypothetic is a struggle in order to fining explainishes for observation or gattered data and in other word,representation of a solotion for the problem  for example sand douns which is gatter in page 6 and or reperisentaion  of solotion for the problem. You may get to or three answer.of course only one answer is true among them but you can be soure of correct answer when primeri information is existed about the problem.other wise you  mention  wrong and imposible  hypothetic basically a logic and scientific hypothetic has two characteristics : 1)concidence to present condition and evedenses 2)susceptility to experiment But there is a wrong whit it that sometimes our hypothetic are not susceptible to experiments .so we should choose another way 5) Hypothesis testing Hypothesis which are represented about a problem do not need usually to the experience .each experiment is drowning of a position which during  that some informations are produced respect to acseptence or regectining of the hypoosetist . if metod of using variables and type of answers which it is expected that aren’t spacifaid crearly ,most of afears related to drowning and gatterinfg data is down and what is remained, is characterizing in the conditions which the works  should be done in that condition 6) Modeling Most of  scientist know using of the model useful for indicating their Hypothesizes in getting to more precise deduces. usually scientist use two types of models which can be named realistic models or visually models. Take a look at two models as follow. what is different between them? which one is more realistic? What cases are useful for modeling? In case of objects are very fine such as atom and we can not see them, how can be be sure about being correct of the model?  You have observe many models of humans and organisms (dolls), air plain, automobile, house and etc. these types of models show a real object in small size. So small objects can be shown  in large scale too. In the scale, important tip is considering of constable ratios between sizes of real steak object and the model. Old Greece philosophers used atom word form smallest particle which can not be divided any more in the substance. In sixteenth century, it was suggested that all of the solid substances contains small spheres which are joined to each other whit a hook. Thirds model explain about manner of solid objects. Anyone who has not observed the atom so far, but all of the characteristic are observed in modern models at the atom electromagnetic forces are replaced to olds hooks but its not obvious if better models will be represented in future. Value of atom model is very high because it is susceptible to change and review. Realistic change faster or slower than models. changing in the models, is representative of change in our knowledge about mention object and this  knowledge is existed from testing of the model. In reality testing of the model is best way to reach to the realities. This point is very important and interesting about the science: 1)the science is innovation of human, s thought and has source in curiousness of logic and imaginations. 2)in spite of knowing much about the world around us now days, there is very un none maters. The science is an infinite road. 7) To report One of important activities in scientific studies is reporting. Scientists have been known necessary reporting after experiment and investigation from far pasts. You can try to provide  the reports of done works. Why is the reporting important? What parts should a report have? Who is geologist? Geologist is who is trained for study of the earth and especially in its outer part  an dworkes . surveying of stones and minerals and others materials of the earth and active prosese in the earth is one of duties of geologists. Most of geologist at the university obtain in enough information in field of  sciences and mathematics. And will be profitiont in geology. Some of the geologist are specialist  in field oif stuy and discovering of the minerals and needed materials such as petrolium, gas, minerals and water. Geology engeeners work in studies of before performance of big construction such as dams, bridjes , roads and etc… with civil engineers. Studies topic for many of geologist is vokano, earthquich,orogany, erosion sedimantions and summery of whole prosses which are susceptible to change of the earth surface permanently. Providing of geology maps which are foundation of many big activates such as mining, petroleum exploration, finding the water, making dams, road constructions which geologist are responsible for them.  Although a geologist obtain some of necessary information in lab but he works mainly with nature. Hence, geologist should pick geology hammer with him and go to field. And passes thought river valleys to summit of the mountains and seeks out minerals, stones and fossils and struggle to survey structures geological phenomena. He should has necessary powerful eyesight and ability of analyze  complicated structures of  the earth. Geology studies in our country which is rich of mineral materials and fuul of gas and oil and olso is comfronted to problems such as water shortage, and destroyer natural events such as earth quich and flood, has specific days geologists works in organs and different parts of our country, ministry of industry and mines, Oil Ministry, department of energy, atomic energy and many of research institutes which are doing and they have a main role in economy and development of the country. Look at to future    You should conclude there are three substantial stages for training:  1-      Study; In order to gather information about the desired issue 2-      Thought; to do more activities and innovation of new methods in making hypotheses and salvation of problems. 3-      Act; To test their hypothesis and Conclusion If you apply these three steps, you will see that all data has led to new questions and new hypotheses are presented and the questions, observations, measurements, and the higher demand measurements. Despite all the modern facilities, we still see methods in science is limited. Not many places like the deep sea, the land and remote areas have not been compiled. On the other hand, with a more precise equipment and tools, experiments are more complex and time information that they obtained, but with more product information larger, more questions too. Importance and usage of geology science Section 1 Water cycle In the mid-seventeenth century, scientists were able to get water to the earth to accurately measure and compare the amount with the amount of water that flows in rivers to take action. These measurements indicated that perhaps five times more land than what flows in rivers, the water receives. If this issue was more complex ((remaining water goes to where?)) Water is constantly in motion and the earth and from earth, air goes into the air. The motion period, the water cycle is. Every year about 500 thousand cubic kilometers of water evaporates and the air that goes in about 86 percent of oceanic surface. The rest of the soil, lakes and rivers gets up in the air. Save over 97 percent of Earth’s oceanic water and remaining 3 percent, the lot is stored polles as ice. Amount of water compared with water under the earth surface, is very much more in this case the water in the atmosphere There is very little compared to others because of low air capacity to store water, reduce water vapor in the atmosphere is. - Water, earth, air condition sets. If there was no water, air temperature during the day and at night more than 100 to less than 100 °C - are reached. If the temperature difference between the different chapters in different parts of polar and tropical temperature was much higher. Part of the water absorb solar energy and when the weather is cold, the stored energy is released slowly. This action, along with the general flow of air in the butter to the mixing of air transportation, climate modification caused the earth to be general. - Through water ((erosion)), ((carry)) and ((sedimentation)) most changes in the Earth’s surface to provide there. Waters to help other natural factors such as wind, constantly they erode the ground rocks and they are settled to earth basins. These sediments results in sedimentary rocks as they exist. - hydrosphere from drinking and agriculture water supply aspect, transportation energy transport, providing food and minerals, are important in human life.  Section 2- air The most vital substance that we have always dealt with it, is air. Everyone usually three meals a day eats and drinks water, but he needs constant air. Endure thirst and hunger for a day, most of us can be easy and even survived several days without food, but no one can be more than a few minutes live without air. Air composition In fact, a series of air gases, water vapor and dust particles is. Must say that the current composition of the air is different in different segments of our goal of combining air, the air is part of the deal with daily. Composition of ordinary air can be two types of gases, vapors and suspended solids was divided. Gases and vapors The most important gases in air vapors in plan 1-2 is inserted. Although the highest percentage of nitrogen components makes up the air, because of gas actually is relatively passive role in human life, no? Of man, the most important gas is oxygen in the air that if the percentage is lower than the limit, may lead to immediate death. Oxygen of the geological processes is important because oxidation is the main factor. Steam has an important role in adjusting the air, but its value is variable. It should be noted however that the composition of air in different parts of Earth’s surface and especially in industrial areas is variable. In this area there some gases, especially carbon monoxide in the air, has an important role. The gas, which unfortunately, its rate of industrial cities like Tehran is growing at very low concentrations is also toxic and may cause death of people.   Air layers Effective thickness of the air based on various factors such as chemical composition, temperature and electromagnetic properties are divided. 1-      Chemical composition  Homosphere  - Composition of this layer of air, as we have already studied. Thickness 80 to 100 (average 90) km  Heterosphere - - Average height of 90 km to the next, and gas composition will change the air, the different layers are separated. 2-      Temperature changes (classification of air layers) Based on air temperature, four layers of troposphere, stratosphere, mesosphere, is divided into and termosphere. The four layers by three levels, called the tropopause, and mezopause and stratopause are separated. Troposphere - the layer of air, from ground level to height of 18-8 km continues and is the heaviest air cortex. Air temperature in the cortex decreases with increasing altitude. Clouds in this layer is usually are concentrated. This layer is limited to the tropopause level. Stratosphere - the layer is placed on troposphere average height and up to 52 km, and extend to the surface stratopause is limited. The middle layer, called cortical ozonosphere. There is containing ozone. Since the upper classes and therefore did record warmer stratosphere, ozone is therefore segments of the air. Since the segments of the upper stratosphere and thus are warmer, so part of segments of the air, stable and have good classification and therefore are called stratosphere. Mesosphere - the layer of 52 to 80 km altitude and because the expansion process is not done creating heat. The temperature decreases with increasing altitude and in the upper layer, i.e the level mezopause to - 90 ° C reached. Thermosphere - the upper air layer forms due to absorption of short wavelength ultraviolet radiation, temperature increases with height, increases in segments of the upper reaches to 1000 degrees centigrade. Ozone layer In height between 20 and 50 km (ie in the stratosphere) layer of ozone gas is not available and not that visible. However, the existence of life depends upon it entirely. Passed between us like the ozone layer dangerous solar ultraviolet radiation has been the skin is severely burned and in case of continuous and intense radiation, may induce skin cancer. Ultraviolet rays are harmful to plants and animals and also affects their health. In 1986, scientists had hit parts of the stratosphere where the ozone did not exist at all. One of these regions was above Antarctica. Smaller area in the high Arctic were found. From that year onwards, the holes in certain seasons appear and during the next season through the process. The main concern of course is that in addition to said holes, set in the ozone layer around the earth is getting low. We correctly cause the disappearance of atmospheric ozone are not aware, but scientists assume that they polluted atmospheric instruments, including the reasons are phenomena. hlorofluorocarbon (CFC) gas that, in the refrigerator and some sprays, etc. are used. This gas, also made the devices and use them, be entered atmosphere. Molecules CFC, when dealing with ozone molecules, they break them. This product is also coming into existence of oxygen. 3-      Electromagnetic characteristics Radio waves in different layers of air are constantly reflecting and thus remit release. Different layers of air, they reflect different waves and in addition, the features are based on them, the two layers of air, called the ionosphere and magnetosphere are divided. Ionosphere - part of the air at an altitude of 400 km is 80 and containing particles with electrical charge is called the ionosphere call. Of course, part of the thick air in which ions are formed, more and reaches as high as 1000 km, but actually focus on the portion of ions that was said and why they say this part of the ionosphere. Its ionosphere is composed of different segments of the radio properties are different with every one of them is able to reflect certain wave-length makes. Magnetosphere- land like a powerful magnet around a magnetic field are created. Radius of action of this field, Korean Air is limited to very short distance away, too, is expanding. The force of magnetic field lines make magnetosphere. magnetosphere r earth against dangerous charged particles from other parts of the Earth’s atmosphere protects come. Air temperature Sun Air is a major source of heat. Of course, the earth as a heat source of thermal energy released their will, but its role against the role of the Sun is negligible. Sunlight reaches the Earth’s atmosphere, but can not air all the thermal energy will attract the sun, but more energy from the sun passes through the air and reaches the ground and after some reflection it is because warm air . Factors affecting temperature changes Air temperature, permanently changing factors such as altitude, latitude and rotation rate on the effective temperature. 1 - height- Overall air layers troposphere means that we work with everyday life, with increasing temperature the height of the surface, decreases because: As we saw just a little part of solar energy directly air is absorbed by the earth and reaches more that this part of solar energy, or release into the air reflection is on. Therefore the earth as a mediator for heat exchange acts and natural that much farther from the ground become more temperature decrease. On the other hand with increasing altitude, concentration of gases in the air, particularly water vapor, will be less. Therefore, direct absorption solar thermal energy is reduced by air. One of the other factors in reducing the temperature in the highlands, which means that air expands when the air is moving around the top, is expanding its and temperature decrease. 2-latitude- In the summer, traveling to coastal areas north of the country is very pleasant. But this season is popular beaches south of country less because it places the heat is overwhelming. Due to the height of the southern and northern shores of our country is practically one must factor other than altitude, the temperature difference is caused. Probably know that air is always cold polar regions and regional air equator always warm. Due to temperature differences in different latitudes, how is the sun. At low latitudes and equator regions, sun almost vertical mode turns around. But whatever the latitudes and low latitudes regions, the sun shines almost vertical mode. But whatever the width of some geographical areas of low latitudes, the sun shines almost to the vertical mode. But much to higher latitudes closer we are, the angle of radiation is less. In other words, a certain amount of solar energy in the equator region, a square meter of land surface are reflected and it heats well, whereas in higher latitudes we are close, the angle of radiation is less. To In other words, a certain amount of solar energy in the equator region, a square meter of land surface are reflected and it heats well if at high latitudes, the same amount of energy reflected and several square is clear that the unit area reaches a lower energy. At large, the difference is remarkable. For example temperature of Air Sweden in northern Europe are always colder than the air in Saudi Arabia which is located in low latitude. Earth’s rotation - with the sunrise energy reaches the earth and the earth will begin to thaw. Will take some time to thermal radiation and the earth begins this phenomenon continues all day. Daily temperature in a sunny day at 14 reaches its maximum and then, low light intensity after sunset and will stop. But because of warm earth, until sometime after the sunset, heat radiation continues. During the night, the air temperature decreases again and then to decrease slightly from the sunrise continues. It should be noted that the presence of cloud, wind and rainfall may be time to change the maximum minimum temperatures. Greenhouse Effect Air inside the greenhouse, ((tail)) and has a sultry mode. That is why a greenhouse with glass-covered roof and the warm air rises, it will encounter and could not be removed. Thus preserving the environment is warming. Like such a phenomenon, also occurring in the air. Short waves that are released from the sun, air easily passes through layers of earth and is absorbed, but after warming the earth, thermal energy as their only long-wavelength waves will be released. There are water vapor and carbon dioxide in the air, largely to prevent the long wave pass issued by the land and therefore, the air temperature during the night or winter does not drop much. In fact, water vapor the air as carbon dioxide Glass Ceiling greenhouses act and therefore, this effect is called the greenhouse phenomenon. Temperature inversion Those who live in Tehran, know that some days, and especially in winter, the media, they announced that due to the inversion, the city will increase air pollution. You know what is this phenomenon? Normally, increasing the height of the surface, troposphere temperature decreases and warmer air near ground level and therefore lighter than the upper segments of the upside and this cause is air displacement. But sometimes the situation is vice versa, ie segments adjacent ground level, with increasing altitude, temperature also increases. In such cases, due to cold weather than being more and heavy and displacement of air upside down and no air comes in Static. Such a situation is called inversion. This situation is usually quiet and no clouds in the winter nights occur. At night, long wave radiation from the ground, which is a little more than a day is received. Therefore, surface temperature decreases rapidly and therefore the cortex adjacent colder air is (of course with the Earth re and warm sunrise, this group of cold air and hot fixes mode inversion is caused.) Inversion of air pollution in cities like Tehran is very important. Because in this case being due to static air, smoke and other gases resulting from automobile and machinery used in the air remains stagnant and could not be dispersed. Warming the earth During the past century, Earth’s average temperature equal to 0.5 ° C have been raising. Although you may think this amount is negligible, but the same amount of time shows that the Earth is warming. A cause of warming the air, coal. Burning of these materials, carbon dioxide is produced and goes into the air. The incidence of gas greenhouse effect has a direct involvement. Another reason, logging host. Around the world, preparing the ground for some reason such as agriculture, mining, oil wells, pastoralist, and urbanization roads, the forests are being through. Barometric pressure By definition, consists of air pressure that the air force at any point, the unit will enter the level, e.g at the seaside, on every square centimeter of surface, equivalent to approximately one kilogram of force with force 9.8 Newton Effect will. What is air pressure? Operating air pressure caused by molecules of air strikes on any surface that is located adjacent to the air. (So many blows per unit area, which eats more, the same time is greater than air pressure). For example, if a closed container in the heat, we increase due to temperature, its molecules move more quickly, and although the number of air molecules within remains constant, but increases rapidly due to the molecules, the number of blows turns to the wall is higher and therefore air pressure inside the container increases. Air pressure in each region during the day and year are remarkable changes. Overall we can say that the level of continents, and in winter nights, air pressure is higher and summer days. Basically in a open environment, pressure, cold air, warm air has more pressure. That is why the heat , air molecules are far apart and the molecular density decreases, which results in less number of particles being less than the number of blows and the air pressure is reduced. It should be noted that local conditions may alter this situation. Wind Wind is moving air, say. Because wind, air pressure differences in adjacent colon and this in turn, due to temperature difference occurs air in two parts. In the open air, cold air is everywhere, is heavier and has more pressure to the parts when the weather is hot, will be going. To help agencies and vane anemometer and wind direction can be identified. General winds Korean Air heat solar energy under the influence, is constantly in motion. Air tropical regions that have less latitude, more high-latitude areas with air is heated. Due to warm air being lighter than cold air is thought that should warm air toward the equator region go up in the cold polar mode it takes Jab. If the earth does not rotate around its axis, such an event occurring and the permanent flow of air between the poles and the equator was there. But the Earth’s rotation, a simple move that will affect saying. Earth’s rotation causes the airflow simply consisted of two polar high pressure center not tropical. But at the equator to pole distance, high-pressure center and several km consecutive pressure is produced, and due to ground motion situational fixed set of two winds occur. In fact, due to rotation of the earth, warm area of the equator is not able to climb the heights along a straight line to move toward the poles, but gradually, toward the East will be diverted and then cooling the Earth’s surface move towards the fall and that around 60 degrees latitude the other a low-pressure center is produced. Despite the successive high-pressure belts and wind caused some low-pressure winds proved to be the most famous winds of the Northern Hemisphere with special order from the northeast to the southwest and southeast of the southern hemisphere toward the northwest blast. The winds move the ships sail past have had a role. Therefore they trade winds or winds Elysee say. Monsoon - in addition to the permanent winds are virtually continuously blast, some winds are stable over the years. For example, the summer season due to warming the air above the continents, regions low pressure is created, while the ocean surface, which is the temperature, pressure centers is produced and the series of relatively strong winds caused the oceans to the continents are. In winter, the situation is contrary and continental temperatures, ie less than ocean temperature, and thus to The winds will be from the continent to the ocean. Sea breeze and land breeze - if you go on vacation to the beach, you probably press the breeze from the sea to dry land or sea to have a sense of blows. Land than sea, are the earlier warm temperatures and earlier to lose. During the day, due to solar radiation, drought is heated rapidly, while the sea air is colder than the land and at sea level so high pressure center and drought in low-pressure center is created that results, the breeze blowing from the sea is dry. Night Earth cooled quickly, while still warming the sea has not lost his. So instead of low pressure and high pressure centers will change and the breeze from blowing dry the sea level. Water vapor in the air In almost all parts of the earth, the air is always some water vapor along with air and can say that there is virtually dry. But the amount of water vapor in the air at different points, different. To express the status of water vapor in the air is different at different points. To express the status of water vapor in the air than two terms of absolute humidity, relative humidity and use. Absolute humidity - mass of water vapor in unit volume of air, moisture is called absolute. It should be noted that absorption capacity is limited and water vapor the air at any temperature, a certain amount of air is able to absorb water vapor does. For example, the amount of moisture required to saturate the air at several different temperatures, listed in Figure 14-2 is. Numbers indicate this fact very well have what temperature is higher, the vapor absorption is also higher. Why in the winter on the internal part of the room drops tiny glass of water sits? Relative Humidity - Absolute humidity of air is not enough to express air quality, because sometimes the moisture in the air it is 5 grams per cubic meter, we breathe easily, while the temperature may be higher, with 8 grams of water in cubic meters, feeling We land. Air quality to express terms of comparing it with saturation, relative humidity term is used. Measuring of relative humidity