Seafloor Sediments: Type and Distribution
Seafloor sediments can be categorized into about five groups depending on the place of origin.
Terrigenous sediments are as a result of deposition of material weathered and eroded from rocks on land. They are basically found just close to their source and reduced in concentration as you move away. Authogenic sediments are produced as a result of chemical reactions of different substances in water. They are also called hydrogenic sediments. Biogenic sediments are formed from mineral deposits like teeth of shell that are produced by living things (Lutgens, 2008, p.
45). Evaporites, phosphorites and ferromanganesse are the common examples. Volcanogenic are sediments that are formed from deposition of materials from volcanic activities. Distribution of depth depends of pressure and temperature of ocean water at that moment and also supply of the soluble substances in water.
Distribution factors affect the location, depth and hence quantity of sediments across the world. These factors are mainly erosion and transport means. When the sediments are transported by water or wind, the size of the rock particles determines the distribution. When particles are very small, they can be transported to far locations (Lutgens, 2008, p. 45). However, for larger and heavier particles, deposition occurs very soon and they get settle near the sources.
Techniques And Efforts for Stabilizing Shorelines
Several techniques have been employed to try and stabilize shorelines across the world today. The techniques are basically either considered permanent or temporary based on the length of period the technique is expected to last. Hard stabilization is used to describe all the structures that are constructed along the coast to limit erosion. There are three main types of this and are also the permanent types: groins, breakwaters and seawalls (Lutgens, 2008, p.
78). A groin is a wall constructed at right angle to the beach so that it can be used to hold sand moving parallel to the beach, breakwaters are walls designed to shield watercraft from the impact of huge breaking waves by having a quiet water zone at the beach. These techniques are very effective in regulating erosion along there coast. An alternative to the hard stabilization are the temporary measure which are not efficient.
For instance beach relocation and replacing of sand. The main disadvantage is that the solution is not long lasting and it’s very costly. As for relocation, the high risk buildings are usually relocated to other areas so that nature can be allowed to reclaim the seashore (Lutgens, 2008, p. 78). However, this is usually faced with problems of resistance where some people are not ready to give up their properties on the coast. Development done at the coast does not automatically lead to soil erosion along the shorelines will be eroded. Activities like coast diving may cause erosion and pollution of beaches but activities like construction dams, roads and other cost structures slow transportation of debris or sand to the coast (Lutgens, 2008, p. 79).
The difference between a void in Ozone and Global warming
The ozone (O3) is a type of a gas that protects the earth or the harmful rays of the sun like the ultraviolet rays. This way, the ozone layer is able to protect the living things on earth from the damage that ultraviolet rays could have caused. The ozone void or hole is the opening in the ozone as a result of its depletion allowing dangerous radiation to reach the earth (Lutgens, 2008, p.
102). The ozone is destroyed by gases called Chloro-fluoro-carbons (CFCs). In normal domestic and industrials tasks, these gases are constantly released to the environment from aerosols, coolants and air conditions.
On the other hand, global warming is the slight increase in temperature cause by different set of gases called hydrocarbons and nitrous gases including carbon dioxide and methane, these gases cause the green effect in the atmosphere and make the planet warmer as these gases trap more heat. These gases do not cause depletion of ozone (Lutgens, 2008, p. 102). The ozone hole is not a causative factor of global warming because the ultraviolet rays only represent a very small percentage, less than 1% of the whole suns radiation. Both phenomena have dire consequences of living things. Global warming affects climatic changes leading to unpredictable weather that affects agricultural production. There are extreme cases of climate like tsunami and so own (Lutgens, 2008, p.
104). The ozone hole on the other hand allows exposure to the UVs. These radiations have devastating impact on health like cancer of the skin, cataracts, sunburns and even immune system problems. In the north polar and south polar areas, the marine life is threatened hence this can have a bad impact on worlds food chain (Lutgens, 2008, p. 106).
Vertical Movement of Air And Precipitation
Clouds are water droplets condensed in the atmosphere because of lower temperature with increases in altitude. This is the reason why vertical movement is so critical for the formation of the clouds.
This movement is achieved by combination of factors including temperature, topography, conventional currents and frontal lift. Convention current work when the earth is heated by sun’s rays and warm air begins to rise and then it cools as the height increases. On the other hand, clouds can form when air is forced to rise along a topography profile like a mountain or forest and this process is referred to as orographic lifting (Lutgens, 2008, p.
121). When the clouds are cooled enough to form larger water droplets it usually comes down as raindrops. The adiabatic temperature changes are also crucial for cloud formation. When a mass of air with a definite weight occupies a definite space with no change in heat then a change in volume will result in change in energy. This kind of change is called adiabatic and it’s important here because, when air is rising, it passes regions of lower pressure and then it increases in volume therefore also decreasing internal energy. A unit fall in internal energy translates to drop in temperature. If the process continues for sometime as air rises, it will reach dew point when condensation will take place (Lutgens, 2008, p.
121). This is how and when rain is formed. This movement is achieved by combination of factors including temperature, topography, conventional currents and frontal lift. Convention current work when the earth is heated by sun’s rays and warm air begins to rise and then it cools as the height increases. On the other hand, clouds can form when air is forced to rise along a topography profile like a mountain or forest and this process is referred to as orographic lifting. When the clouds are cooled enough to form larger water droplets it usually comes down as raindrops (Lutgens, 2008, p. 126).
The adiabatic temperature changes are also crucial for cloud formation. When a mass of air with a definite weight occupies a definite space with no change in heat then a change in volume will result in change in energy. This kind of change is called adiabatic and it’s important here because, when air is rising, it passes regions of lower pressure and then it increases in volume therefore also decreasing internal energy. A unit fall in internal energy translates to a drop in temperature. If the process continues for sometime as air rises, it will reach dew point when condensation will take place.
This is how and when rain is formed (Lutgens, 2008, p. 129).
Coastal and Mountainous Regions are Often Much More Windy
Wind is movement of air currents in the atmosphere. Wind is not a unique phenomenon to the earth and it simply happens when air gets heated and then rises and cooler air replaces it in a rush. Winds are classified in different categories depending on the causes, the geographical location they pass and the impact they cause (Lutgens, 2008, p. 143). Coats and mountainous areas are often windy because the mechanisms causing movement or air are common in these areas. The heating of the earth at the coastal often results in a warming of the sea is a somewhat slower manner that the ground as a result of the factors of heat specific capacity.
When air above land is heated, it becomes lighter and rises, causing a pressure gradient, cooler air rushes from the sea to replace it (Lutgens, 2008, p. 146). The process repeats severally making coastal areas very windy. In mountainous areas, there is combined effect of differential heating and topography.
The heating of the mountains often occurs when the sun emerges, and with time, the slopes are heated as well. However, there is a shielding effect on the valleys. Consequently, temperature inequalities are experienced and on the slopes, the rising warmer air is quickly replaced by the cooler air, and the vice versa is also true during the afternoons (Lutgens, 2008, p. 148). There is hence current called valley and mountain breeze.
Atmospheric Pressure Is The Best Indicator of weather change
Basically when there is change in weather or climate, the atmospheric pressure is directly affected even with the slightest change. This therefore means that atmospheric pressure is the most pertinent element of weather prediction (Lutgens, 2008, p. 165).
It’s and established fact that high pressure air tends to flow towards low pressure zones in currents that are similar to wind speed and even direction, temperature variation and the different types of precipitation; the rate at which pressure changes will therefore be the most accurate indicator of the change in weather, especially for storms. Air pressure and air movement are the main causes of weather characteristics ranging from winds, precipitation, and temperature changes and therefore long time climatic condition of the place (Lutgens, 2008, p. 165). In order to detect a change in weather, the atmospheric pressure variation will accurately show the change.
This is the process that a star experiences sequential fundamental changes during the period of its life. Based on the size, the star lifetime can last few million to several trillion years. The changes are very slow and gradual and cannot be observed easily taking several centuries. Several stars at different stages of life can be studied to enhance comprehension of the progress (Lutgens, 2008, p.
175). Stages of stellar evolution begin with protostar. This is the early stage where the star contracts from interstellar gas (basically hydrogen, helium and some heavy elements). This stage last several millions of years and temperature increases from gravitational energy hence evoking thermonuclear reactions which produces heat and light. Mature stage is the phase when the star is fully formed and shines steadily as hydrogen is reacted to form helium. The light produced is determine by the chemical makeup, the temperature and its size.
Last stage is old stars and its death. This is when the helium gas in the star has increased. Nuclear reactions are more and more hydrogen is lost (Lutgens, 2008, p. 176). In order to accommodate the reaction material, the outer envelope increases to hold the energy being produced.
As helium core is surrounded by cooling gas, the star becomes red mass which then contracts the core. Burning starts and the process is revered. The star begins to shrink and looses luminosity.
Atmospheres of Jovian and terrestrial planets
Planets are usually classified into categories based on their physical characteristics. The inner planets which are close to the sun are mercury, Venus, earth and mars. These planets are also called terrestrial planets.
They are smaller and solid (Lutgens, 2008, p. 195). The outer planets are Jupiter Saturn, Uranus and Neptune which are not as solid as inner planets; they are also called Jovian planets. . The differences of their atmospheres are critical.
Terrestrial planets have thick atmospheres that are able to cause varied weather conditions. They have tectonic caused features like volcanic features and rift valley. Jovian planets do not have such features. The surfaces of Jovian planets are covered by heavy gases including mostly helium and hydrogen. The bluish appearance of these planets is due to the helium gas (Lutgens, 2008, p. 195). Terrestrial planets on the other hand are covered by nitrogen gases and carbon dioxide.
The similarity between the different classes of planets it’s that their atmospheres are both made up of gases.
Lutgens, T. T.
(2008). Foundations of Earth Science. Upper Saddle River, New Jersey: Pearson Prentice Hall