Earth Science |
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| Course Code | BEN204 |
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| Fee Code | S3 |
| Number of Assignments | 9 |
| Duration (approx) | 100 hours |
COURSE STRUCTURE
There are 9 lessons as follows:
- Structure and Forces
- Rocks and Minerals
- Surface Changes
- The Oceans
- Air and Weather – Meteorology intro, etc.
- The Greenhouse Effect
- Global Weather Patterns
- Geological Time
- Modern Environmental Issues
Each lesson culminates in an assignment which is submitted to the school, marked by the school's tutors and returned to you with any relevant suggestions, comments, and if necessary, extra reading.
AIMS
On successful completion of the course you should be able to do the following:
- Describe the major structural elements of Earth and the major internal forces which affect them.
- Classify rocks and minerals according to their characteristics and formation.
- Explain external processes that that cause topographic and soil changes on the earth’s surface.
- Describe the oceans of the earth and their role in global processes.
- Describe the earth’s atmosphere and the forces which create weather.
- Describe some well known effects of particular atmospheric conditions like the Greenhouse effect.
- Identify global weather patterns and their relationship to different climates.
- Describe the way in which the earth’s surface has changed over time.
- Identify environmental issues which are of current significance.
WHAT THE COURSE COVERS
Here are just some of the things you may be doing:
- Research how a mountain/mountain range in or near your region was formed.
- Explain plate tectonics.
- Collect and classify rock samples as either sedimentary rock, igneous rock, or metamorphic rock.
- Describe four ways that weathering breaks down rocks to help form soil.
- Explain how the speed of a stream affects the shape of the landscape.
- Name the three main layers of the ocean, describe the characteristics and ocean life in each.
- Keep a record of atmospheric and weather changes in your environment.
- Explain the highs and lows associated with air pressure, and how they affect weather.
- Create a questionnaire to determine understanding of the Greenhouse Effect or the Ozone layer.
- Explain why your region has its overall climate.
- Research what life forms (plant and animal) inhabited your region before the formation of humans.
- Identify the rules and laws used to date fossils.
- Research an environmental problem in your area, and discuss possible solutions.
Extract from Course Notes:
FORCES CAUSING SURFACE CHANGES
Weathering
Weathering is the term used to describe the processes by which rock is disintegrated and decomposed on or near the earth’s surface, due to external forces such as wind, water and temperature. Weathering is the response of earth matter to environmental changes which disturb the equilibrium or balance, which can only be regained by the breakup of rock into smaller pieces, and/or removal of rock material from one place to another. Because of these changes, rock is fragmented by various forces, decomposed by chemical action, or both.
Mechanical weathering
This occurs when physical forces break the rock into smaller and smaller piece3s without changing its mineral compositions. The broken rock material now has more surface material on which chemicals in the environment can act. Therefore, mechanical weathering speeds up the processes of chemical weathering.
Some mechanical weathering processes are:
Frost wedging – where alternate freezing and thawing of water between rock particles causes them to shift, or break apart. It is most common in mountain regions where it creates large piles of fallen rock material called talus slopes;
Unloading – when concentric slabs of igneous rock break loose from large bodies of igneous rock. This sheeting action occurs after erosion of surface soil and plants has removed the pressure from igneous rock (eg. Granite), and outer layers of rock expand more quickly than underlying rock. as erosion;
Thermal expansion – occurs especially in areas where daily variation is great, and temperature changes weaken the rock, causing it to shatter. This is most likely to occur after rock has been previously weakened by chemical action.
Organic activity – occurs, for example, when growing plant roots wedge rocks apart, or burrowing animals move material to the surface where weathering can cause it to disintegrate.
Chemical weathering
Processes that alter the internal structure of minerals by removing or adding minerals result in chemical changes that disintegrate the rock. This can be done by:
- Solution – the dissolving of certain materials (such as very soluble halite or table salt) in water. Acids in the water will increase the solubility (ability to form a solution) of many minerals. Therefore, if acids such as carbonic acid are present in rain, the rate of chemical weathering is greatly increased.
- Oxidation – the process of rusting when oxygen combines with iron the form iron oxide. Mining can hasten this process, and as mine acid breaks up rock, acidic sediments make their way to water systems, killing fish and polluting the water.
Mass wasting
This process refers to the downslope movement of rock and soil under the influence of gravity. As rock is broken apart and weakened by weathering, the weight of unstable masses of rock or soil can cause them to roll or fall downslope in avalanches, earthflows, mudflows, or slumps. Slopes that are too steep also cause mass wasting. Material involved in mass wasting includes debris, earth, mud or rock. It may move downward in a fall, a slide or a flow.
Erosion
Water is moved in the hydrological cycle that results in evaporation and rain. Water is also moved along the earth’s surface by the processes of erosion, which create streams, lakes, valleys, levees, deltas, alluvial fans and a host of other landforms. Erosion achieves its effects by sculpting or moulding the landscape through the action of water (or wind), and by transporting rock and sediment from one place to another. Areas of rich soil, such as the Nile Valley, can result from these processes.
Erosion is also largely responsible for the formation of deserts. In hot areas where vegetation is scarce, or in areas where vegetation has been removed by human or animal activity, the soil is easily picked up by winds, which can transport it great distances. Combined with the greater evaporation of water that occurs in these regions, erosion can lead to the desertification of great areas of land. The mineral soils (sands) that result are easily carried in winds to neighbouring areas, dumping great quantities of sand to create new or larger deserts.
Other Courses/Studies we offer:
You can also study Certificates, Associate Diplomas or vocational (career) studies in Ecology, Botany, Plant Ecology, Zoology, Horticulture (Nature Park Management), Wildlife Management, Environment Management, Marine Studies, Waste Management and much more.
Earth Science develops an ability to identify and describe the Earth, its structure and explain processes that affect change in the structure and composition of the earth. Learn about rocks and minerals, meteorology, global weather patterns, the oceans, surface chances (eg. earthquakes and volcanoes), geological time and more. 