Earth Science

LEARN ABOUT WEATHER, ATMOSPHERE, ROCK, SOIL

...and everything that makes up and drives changes in the physical world we live in

Earth science provides a solid foundation that underpins knowledge in many other sciences, including atmospheric and weather changes, environmental issues, horticulture and agriculture, soil chemistry and more. Understanding how rocks are formed and break down helps us understand soil structure and development; learning about key environmental cycles helps us act against pollution and climate change, develop new technologies, and even monitor and predict atmospheric changes and weather patterns. Studying plate tectonics helps us understand earthquakes, eruptions, and the structure of the ground beneath our feet.

Excellent for developing a richer understanding of the environment and environmental resources, ecotourism, and more.

Lesson Structure

There are 9 lessons in this course:

1. Structure and Forces
   • Scope and Nature of the Earth and it's Structure
   • Continental and Oceanic Crust
   • Continental Drift
   • Sea Floor Spreading
   • Plate Tectonics
   • Plate Boundaries; divergent boundaries, convergent boundaries
   • Transform Faults
   • Volcanoes; shield volcanoes, cinder cones, composite conesmagma, pyroclastic flow
2. Rocks and Minerals
   • Definitions
   • Mineral Properties; crystalline form, luster, colour, streak, hardness, light transmissioncleavage, fracture, etc
   • Mineral Groups
   • Silicates
   • Non Silicate Minerals
   • Rocks; formation, texture
   • Sedimentary Rocks; derital, chemical and biochemical rocks
   • Metamorphic Rocks
3. Surface Changes
   • Introduction
   • Weathering
   • Mass Wasting
   • Erosion
   • Glaciers
   • Streams; birth of a stream, stream flow, deposited stream sediment
   • Ground Water and Land Subsidence
   • Aquifers and Confining Beds
   • Soil; parent material, time, climate, life forms, slope
   • Soil Profile, horizons
4. The Oceans
   • Scope and Nature of Oceans
   • Sea Water
   • Currents
   • Coriolis Effect
   • Geostrophic Flow
   • Land Scale Currents
   • Convergence and Divergence
   • El Nino
   • Waves
   • Tides
   • The Ocean Floor
   • Shorelines
   • The Marine Food Chain
5. Air and Weather
   • The Hydrological Cycle
   • The Atmosphere
   • Atmosphere and Circulation of Essential Elements
   • Structure of the Atmosphere, Troposphere, Stratosphere, Mesosphere, Seasons
   • Solar Radiation
   • The Greenhouse Effect
   • Weather
   • Temperature Control
   • Air Pressure
   • Wind; Local Winds, Wind Erosion, Wind in Arid Climates
   • Thunderstorms
   • Tropical Cyclones
   • Tornadoes
6. The Greenhouse Effect
   • Introduction
   • Global Warming
   • Anthropomorphic Changes to Global Climates
   • Ozone Layer and Ozone Destruction
   • Atmospheric Pollutants
7. Global Weather Patterns
   • Climate
   • Climate Classification; Tropics, Dry Climates, Humid Mid Latitude and Mild Climates, Polar Climates, etc
8. Geological Time
   • Geological Time Scale
   • Relative Dating
   • Inclusion
   • Correlation
   • Types of Fossils
   • Radiometric Dating; radiocarbon dating, radioactivity, half life
   • Geological Time
9. Modern Environmental Issues
   • Balance of Nature
   • Major Current Environmental Events
   • Resource Depletion
   • Conservation Issues
   • Pollution and Waste

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

• 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 You Will Do

• 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.

FORCES THAT CAUSE 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 pieces 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.

WHY CHOOSE US?

• Our courses focus on learning -if that is your priority choose us.
• High Standards -Our tutors are university trained, with a degree level training in science
• Easier Studying -We do not push deadlines like some colleges....you can work at your own pace.
• Practical and Realistic -being outside the government system, we are not influenced by political whims and changes; nor are we preoccupied with satisfying Government beaureacrats at the next audit. -We simply concentrate on helping you learn.