Earth and Space Science - Report Example

Earth and space science al Affiliation) Question one Rock cycle is the of how the sedimentary, metamorphic and igneous rocks undergo dynamic transition over a given geological time. The rock cycle transition happens over a long time as earlier stated above and these changes are influenced by different tectonic factors (Harra 2004). Below is how the different rocks are formed; Igneous transition Rocks pushed into the earth surface melt into magma which is hot molten rocks and they stay molten in state but if there are changes in the temperature the molten may solidify and that’s when they become igneous and then named intrusive rocks while those that find their way up to the earth surface they are called extrusive rocks. Intrusive rocks have a more coarse texture compared to the extrusive rocks that are fine textured. They are formed through cooling and crystallization of the magma. Metamorphic transition This is the transition caused by the exposure to high temperatures and pressure on large bodies of rocks over wide areas. Metamorphism is the process of transforming rocks into metamorphic. Recrystallization of the rocks due to exposure to extreme heat temperatures also alters the rock through introduction of chemicals into the rock. Sedimentary transition Sedimentary rocks are formed through erosion and weathering of the unstable rocks exposed to the atmosphere. Sedimentary rocks are a collection of small fragments of products of same origin which are buried into the ground. It can also be formed from minerals bearing solutions that have been deposited at one large area. The transition results in two types of sedimentary rocks clastic and non-clastic. Clastic are formed from collection from other elements that have been deposited in layers. Non-clastic rocks are formed from the water precipitates or chemical precipitates. Collision convergent boundaries These are actively deforming regions in which two or more tectonic plates move towards each other causing them to collide and causing mountains. High pressures, melting of the plate and also friction between the plates causes the collision. For boundary to form clearly there must be a weak continental crust and a more dense oceanic plate and they must move towards each other and collide. Volatiles have been seen to be present during the collision boundary and with this they cause volcanic mountains. continental-oceanic convergence Significance of radioactivity research made by Liese Mietne Liese Mietne was born in a Jewish family; she schooled normally and was the first woman with a doctorate degree in university of Vienna. Mietne together with Frisch coined that nucleus of the atom could be split to many smaller parts and that there were no naturally occurring and stable elements existed after Uranium. She discovered that the uranium ore was more radioactive than the atom itself. She together with Hahn discovered protactinium isotope that later other researches would use to explore it. She also discovered polonium which helped other researchers to understand fussioning. Together with other researchers she discovered Radium which was closely related to barium. Liese Mietne came up with the word radioactivity to explain the invisibles rays emitted during reaction of the uranium. This word helped other researchers to understand the emission of heat from the reaction that occurred. Liese Mietne was involved in Manhattan project in that earlier she had succeeded in knowing the exact weight of the uranium isotope and this helped in the making of the first two atomic bombs. Nuclear waste disposal Nuclear waste is very dangerous if not handled appropriately; hence those elements with radioactivity are disposed according to the already set rules and regulations. The first step to disposing of the wastes is by grouping them according to their toxicity (Harra 2004). By this we have two groups; Low-level wastes This composes of tools or filter that contains less amounts of short lived radioactivity and they do not require protective gear when handling them. They usually contain only a small percentage of the radioactivity and the large part is just the volume of the element. They are usually disposed of through incineration to reduce their volume and then the residue gotten is buried deep in compost landfills. Another way of disposing off low level wastes is through dilute and disperse method. Low level wastes are first diluted to accepted levels of the uranium and they are followed by dispersion of the end material through coating the waste with the natural soil and the disposed off in a shallow land fill. High level wastes These are wastes gotten from the burning of uranium and other highly radioactive elements. These used fuels are stored in sites that are least accessed by other people and mostly are buried deep into the earth surface. Before burring them they are usually coated to avoid leaking of the radioactive material into the earths surface and causing absorption into the water that can later be used to drink and cause sickness to the human beings. Liquid wastes are solidified before disposal. Aluminium coating is used to coat them after the clay has been dried on them and then they are now buried deep down either in cylinders or large round objects. Some are dipped in water to decrease the high temperatures they emit during their reaction. Contain and isolate is a commonly used method of dealing with high level waste in that the wastes fuel is packed in containers and these containers are contained in underground storage for them to lose their reactivity and also waiting for them to be used in other reactors. Canadian alternative is used where the waste is covered with clay and then coated with lead casings then lowered to the ground. Drilled channel Buried waste To come up with a disposal site great research should be done in the area to be used. Detailed background information about the area should be gotten first from the relevant authorities involved. The type of rocks available in the area should be accounted for too. The steps include; The site should be far from public access or away from where other public can access. The rocks should be technically stable in that there should be no history of ground movement or evidence of improper lying of the rocks. The rocks should have few cracks or fissures this is to avoid instability of the ground or sipping of other minerals in the area. The rocks themselves should be able to lose heat at a faster rate this helps the fuels stored there to cool down, it also helps the uranium producing heat to cool and avoid explosion. Geological setting Uranium roll front mineralization Uranium ore is recoverable concentrations of uranium fragments collected inside the earth’s crust. Uranium ore is formed through porosity and reduction- oxidation potential. They are easily transported by ground water after being dissolved. Most of the uranium ore is formed from the sedimentary rocks in the ground and due to its incompatibility aspect; it is highly deposited at one area hence forming a big ore. Uranium containing rocks can leach and lead to deposition uranium deposits below. Granite vein mineralization A vein is a great mass of rock occupying a channel or a slit. They are found in discontinuous irregular fissures. The granite vein is usually full of the blocks of the rocks and it is very difficult to distinguish the start from the end of the fringe. Granite veins, although have well defined sharp margins compared to the other mineral veins. Granite vein is also more coarse than the nearly lying rocks and the older the vein the coarse the rocks and this means the rocks did not cool properly. Granite vein mineralization and uranium roll front mineralization interrelate because the uranium is formed before the granite ore veins. Then when the magma has been depleted the flow slowly outside through the already formed uranium ore and it passes through the crevices and cooling hence the granite vein are formed. Ionizing radiations Radiation is the release of energy by different certain elements in the environment. Ionizing radiations are the type of radiations that convey large enough energy to release electrons from the different atoms and molecules and in so doing they ionize them. Ionizing radiations are found in 3 different types namely; alpha radiations (α), beta radiations (β), gamma radiations (ϒ) and neutrons (n). Alpha Radiations (α) These types of radiations consist of a fast moving helium nucleus bounded to two neutrons and two protons (Harra 2004). They are generally weak compared to the other type of radiation and they can be stopped using a piece of paper. They are short range cannot penetrate human skin due to it the fact that it is charged and has a larger mass. Alpha radiations are only harmful when inhaled or swallowed or when absorbed through open wounds. These radiations are gotten from the decay of some heavy metals in the universe. Beta Radiations (β) They consist of neutrons that are of small masses and with variable energy, they also consist of high speed, high energy particles (Harra 2004). These rays are halted by aluminium casings. Clothes can also provide some degree of protection against those radiations. They are either negatively or positively charged. Gamma Radiations (ϒ) and X radiation These radiations consist of highly energetic photons that are absorbed and penetrate high dense materials. They penetrate the human skin readily. Gamma radiations are gotten from the ejection of energy from the atom nucleus left behind after decay of the other radiations (Harra 2004). The difference between a dosimeter and scintillometer/ spectrometer A dosimeter is a device used to detect the amount of exposure one has been exposed to at a given time during the working hours (Harra 2004). There are crystals in a dosimeter that glow at the moment they are exposed to the radiation rays. The light produced is then later measured to identify the rate the worker has been exposed to. The advantage of this method of measuring is that they are able to store information long after the exposure has occurred. A scintillometer is also used to detect the light one is exposed to and also emits light to show contact with the rays, but for the reaction to take place there must be a struck. Their difference from the dosimeters is that this scintillometer cannot take pictures of the reaction. This type of radiation monitoring measures only high exposures, but until they are configured will they measure low exposures. Scintillometers cannot be affected by the environmental factor, whereas the dosimeters can be affected. Dosimeters can distinguish the different radiations by their energy levels whereas the spectrometry can only measure the actual number of the colliding atoms. We need these two types of radiation monitoring because when they work together they help one to exactly know the type of radiation a worker is exposed to and to which amount the worker is exposed to. They also help to measure a wide range of radiations from lower grades to the high grades (Harra 2004). Reference Harra, L. (2004). Space Science. London: Imperial College Press;. Read More