Earth Science: The Ocean and Atmosphere - Assignment Example

Earth Science - The Ocean - (Ch. 14 Discuss the topographic features of the ocean floor. The topographic features of the ocean floor is composed of four principal depth zones known as the continental shelf, oceanic ridge, abyssal plain, and the oceanic trench. (McConnell, 2001a) The continental shelf, the first depth level of approximately 0 – 150 meters adjacent to the continental masses of the land slopes gently towards the ocean from the coastline close to the passive margin. The shelf’s width usually increases as the sea level rises. In case the sea level falls below the normal level, the width of the shelf eventually decreases. Between the continental shelf and the second depth level known as the abyssal plain is the continental slope and rise. The continental slope is found where the gradient of the ocean floor increases from the adjoining shelf. When a submarine canyon passes through the continental slope, the sediment that comes from the continental shelf falls into the continental rise. The repeated effects of the submarine canyon concerning the transfer of sediments from the continental shelf to the continental rise causes the gradient of the slope that is connected to the abyssal plain to decrease. The third level of the ocean floor known as the oceanic ridge system is the longest mountain range system and is connected with the plate tectonics. There are a total of eight major tectonic plates located in North American, South America, Pacific, Nazca, Eurasian, African, Antarctic, and Indian-Australian. (McConnell, 2001b) Specifically the movement of these plates could result to the opening and closure of the oceans which results to the disassembly of the continents and earthquakes. The last depth level is the oceanic trenches that are commonly found along the active margins that are bound between the two plates. Most of the trenches that are adjacent to the land areas are commonly found in the Pacific Ocean and are most of the time asymmetric and has a steep side that heads toward the adjacent land mass with a hadal plain that forms at the floor of the trench. (UPRM, n.d.) 2. Discuss biogenous, hydrogenous, and terrigenous sea floor sediments. List examples of each type. Biogenous – are sea floor sediments that are derived from marine organisms that dies and settles on the sea floor. Ex: Calcium-carbonate (CaCO3) that comes from plant planktons known as coccolithophores; and animal plankton known as foraminifera. (Washington, n.d.) Hydrogenous – are sea floor sediments that are derived chemically out of the seawater. Ex: polymetal sulfide wherein the ions are dissolved from the ocean crust when mixed with hot water and allowed to precipitate when in contact with cold water. (Washington, n.d.) Terrigenous or Lithogenous – are sea floor sediments that are derived from broken bits of rock. Ex: turbidites, volcanic ash, and red clays and/or brown mud. (Washington, n.d.) 3. Discuss the major oceanic current system. Which factors seem to be involved in producing them? There are two types of oceanic currents namely the surface currents (surface circulation) which is roughly 10% of the ocean water and the deep water currents (thermohaline circulation) which is composed of up to 90% of the ocean water. (USC, n.d.) The deep water circulation is usually caused by the driving forces of density (salinity and temperature of the water) and gravity. The two types of forces that move the ocean current are the primary and secondary forces. The primary forces include solar heating, winds, gravity, and coriolis whereas the secondary forces are primarily influenced by the flow of current. 4. What is the average salinity of the ocean? Where do the elements in sea salt come from? Describe the processes that affect seawater salinity. For each process, indicate whether water is added or removed and if it decreases or increases salinity. The average salinity of the ocean is between 33 – 37 parts per thousands / practical salinity units (ppt or psu) or 35 ppt. Around 90% of the sea salt comes from sodium chloride or ordinary table salt while the rest is composed of magnesium, sulfur, calcium, and potassium. (UCAR, 2002) Most of these elements come from the gases that have been emitted form the volcanoes. Precipitation and evaporation has an effect to the salinity of the ocean water. When the ocean water evaporates, the salt content of the ocean water becomes more concentrated. The effect is the other way around when the ocean water precipitates. - The Atmosphere - (Ch. 16) 1. Compare and contrast the concepts of weather and climate. In which ways are they similar? In which ways are they different? Briefly describe how climates are classified. Weather is usually used to describe the minute-to-minute or day-to-day changes in the precipitation, barometric pressure, temperature, and wind condition within a specific geographical location. For example, yesterday was a sunny day. On the other hand, climate refers to the average condition of the atmosphere or weather within a long-term period such as yearly basis. For example, winter, spring, summer, and fall. (U.S. EPA, 2006a) The only thing that is similar between weather and climate is that both concerns the changes in precipitation, barometric pressure, temperature, and wind condition within a specific geographical location. 2. Name and describe the forms and heights of clouds. The two forms of basic types of clouds are cumulus and stratus. The cumulus clouds are formed within the rising air currents showing the unstable air condition. On the other hand, the stratus clouds are formed in a horizontal layers when the moist air is cooled below the saturation point. Depending on the height, clouds are classified as high clouds, middle clouds, low clouds, and clouds of vertical development. Under the high clouds include the cirrus (CI), cirrocumulus (Cc), and the cirrostratus (Cs). The cirrus is usually very high, thin and wavy spray of white clouds that are made up of slender and delicate curling wisps or fibers. Cirrocumulus are thin clouds that looks like cotton or flake-like. Cirrostratus are very thin high sheet clouds wherein the sun or moon is visible and produces a halo-like projection. Examples of middle clouds are altocumulus (Ac), altocumulus castellanus (Acc), and Altostratus (As). Altocumulus are layer or series of patches of clouds that forms into a group or lines. Altocumulus castellanus normally appears like turreted whereas the altostratus represents like a thick veil of grey clouds that could almost cover the whole sky. The low clouds include the stratus (St), stratocumulus (Sc), and the nimbostratus (Ns). Stratus clouds are layer of clouds that looks like a fog that is not resting on the ground. Stratocumulus are layer or series of patches of rounded masses or rolls of cloud. Lastly, the nimbostratus are low layers of dark grey clouds. (Carnegie, 2007) 3. Discuss maritime tropical (mT) , maritime polar (mP), continental tropical (cT), and continental polar (cP) air masses. Where do they originate? What type of weather do they usually indicate? Maritime tropical are masses of air that can be found in warm tropical waters of Mexico. The tropical air masses flow towards the north during winter season. (University of Illinois, n.d.) A sunny day is usually expected with this type of air mass. Maritime polar are air masses that comes over the cold ocean currents or the significantly high latitude of the ocean waters. The different with this type of air mass is that it could produce fog, drizzle, cloudy weather, and a long lasting light and/or moderate rain. (Haby, n.d.) Sometimes this type of air mass represents the possibility of snow. The continental tropical is a mass of air that are characterized by a low dewpoints and a range of warm to a hot afternoon temperature. (Haby, n.d.) This causes a very hot temperature during the day and a little cool at night during summer season. Continental polar are air masses that comes from the cold arctic that originated from the snow that covers the regions of northern Canada. (University of Illinois, n.d.) The possibility of snowing is very high with the present of this type of air mass. 4. Discuss the greenhouse effect. Compare and contrast the greenhouse effect on Venus, Earth, and Mars. A balanced greenhouse effect on Earth is necessary for humans to live. However when the temperature increases uncontrollably, humans and other living creatures could die. (U.S. EPA, 2006b) Mars can become a future habitat for human beings when a synthetic greenhouse gases is injected into its atmosphere. (Britt, 2005) On the other hand, it is impossible to create a greenhouse effect on Venus because of its high surface temperature. The different atmospheric composition in Venus is made up of 96.5% carbon dioxide and zero water. Since water is essential for human beings to live in combination with a significantly lower carbon dioxide content in the atmosphere, it is impossible to live in Venus. (Venus, n.d.) *** End *** References: Britt, R.R. (2005) ‘The Greenhouse Effect’ < http://www.space.com/ > Carnegie, C. (2007) ‘Flight Environmental Clouds’ < http://www.allstar.fiu.edu/ > Haby, J. (n.d.) ‘Maritime Polar Air Mass’ < http://www.theweatherprediction.com/ > McConnell, D. (2001a) ‘Depth of the Ocean Floor’ Oceans and Coastlines. < http://www.mhhe.com/ > McConnell, D. (2001b) ‘Plate Tectonics’ Oceans and Coastlines. < http://www.mhhe.com/ > UCAR (2002) ‘Salinity – Dissolved Salts, Measuring Salinity’ University Corporation for Atmospheric Research. June 2, 2002. < http://www.windows.ucar.edu/ > University of Illinois (n.d.) ‘Maritime Tropical Air Masses’ < http://ww2010.atmos.uiuc.edu/ > UPRM (n.d.) ‘Seafloor Features’ < http://geology.uprm.edu/ > U.S. EPA (2006a) ‘Climate and Weather’ < http://epa.gov/ > U.S. EPA (2006b) ‘Greenhouse Effect’ < http://epa.gov/ > USC (n.d.) ‘Ocean Currents and Climate’ < http://earth.usc.edu/ > Venus (n.d.) ‘The Greenhouse Effect: Why the Surface is So Hot’ < http://ircamera.as.arizona.edu/ > Washington (n.d.) ‘Sediments’ < http://www.ocean.washington.edu/ > Read More