I. Earth Systems and Resources (10-15%) •1.      Earth Science Concepts(Geologic time scale; plate tectonics, earthquakes, volcanism)•2. The Atmosphere(Composition; structure; weather and climate; atmospheric circulation and the Coriolis Effect; atmosphere- ocean interactions; ENSO•3. Global Water Resources and Use(Freshwater/Saltwater ; ocean circulation; surface and groundwater issues; •4. Soil and Soil Dynamics (Rock cycle; formation; composition; physical and chemical properties; main soil types; erosion and other soil problems; soil conservation)

•Geologic Time Scale- A record of Earth’s history, beginning 4.6 billion years ago, that shows events time

units, and history.

MAJOR SUBDIVISIONS OF GEOLOGIC TIME:

1.Eras- based on differences in life-forms. Example: Mesozoic Era is ended by the marked extinction of dinosaurs and many other organisms about 66 million years ago.2.Periods- based on the types of life existing at the time and on geologic events3.Epochs- subdivisions of periods. Only the Cenozoic Era is subdivided further into epochs.

•Theory of Plate Tectonics- states that Earth’s crust and upper mantle are broken into sections. These sections (plates) move around on the mantle. •Plates- Composed of the crust and a part of the upper mantle. This rigid layer is called the lithosphere. Below this is called the asthenosphere. The less-dense plates of the lithosphere float and move around on the denser asthenosphere. •Plate Tectonics explain: 1.Volcanoes 2. Earthquakes 3. Oceanic Trenches 4. Mountain range formation

TYPES OF PLATE MOVEMENT:1. DIVERGENCE- occurs when 2 plates move from each other2. CONVERGENCE- occurs when an oceanic plate is forced under a continental plate3. TRANSFORM BOUNDARIES- occurs when 2 plates slide past eachother

Earthquake- the movement of the ground, caused by waves from energy released as rocks move along faults. Faults- surfaces along which rocks on either side of a fault move in different directions relative to fault surface.

Volcano- a vent in Earth’s surface that often forms a mountain built of lava and volcanic ash, which erupts and builds up.

What Causes Volcanoes?When magma is forced upward.

Composition- a mixture of gases with some suspended liquids and solids.Contains: Nitrogen (about 78%) and Oxygen ( about 21%) and Water Vapor.

Structure: Atmospheric Layers 1. Troposphere2. Stratosphere3. Mesosphere4. Thermosphere5. Exosphere

•Weather is short-term atmospheric conditions in an area. It is typically considered in hours or days. •Much weather activity is due to interactions between leading edges or fronts of moving masses of warm or cold air.•Changes in atmospheric pressure also affect weather.•Tornadoes and tropical cyclones are extremes of weather that cause much damage. Tornadoes form over land, and tropical cyclones form over warm ocean waters.

•Climate is the long-term atmospheric conditions of a region, typically considered over decades. •Average temperature and average precipitation are the two major factors that determine the climate of a region.•What determines different climates?1. The amount of incoming solar energy per unit area of land 2. Air circulation over surface of the earth3. Water circulation determine the different climates that occur.

ENSO (El Nino Southern Oscillation)El Nino effects:

Warmer water along coastsPoor fishing conditionsLess Atlantic hurricanesFlooding in Peru, EcuadorDrought in Brazil, Australia, AfricaWet conditions in FloridaWarmer Canadian winters, wetter springs

La Nina causes:More Atlantic hurricanesMilder midwestern winters

Four major factors determine global air circulation patterns.1.        Uneven heating of the earth’s surface: The equator is heated more than the poles. This is due to the angle of the sun’s rays on different parts of the Earth.2.        Seasonal changes in temperature and precipitation due to the tilt of the Earth3.        Rotation of the Earth on its axis results in the Earth moving faster beneath air masses at the equator and slower at the poles: Belts of prevailing winds are the result.4.        Properties of air, water, and land: Water evaporation sets up cyclical convection cells. These occur both vertically and from place to place in the troposphere. The result is an irregular distribution of climates and patterns of vegetation from pole to pole.

Coriolis effect- the effect of Earth’s rotation on the movement of air masses; changes the direction of air flow.Example: Causes air moving south in the northern hemisphere to turn westward. The flow of air caused by differences in heating and by the Coriolis effect create distinct wind patterns on Earth’s surface

•Soil texture is the single most important physical

property of the soil. Knowing the soil texture alone will

provide information about:

1) water flow potential,

2) water holding capacity,

3) fertility potential,

4) suitability for many urban

uses like bearing capacity

Sand has less nutrients for plants than smaller particlesVoids between sand particles promote free drainage and entry of airHolds little water and prone to drought

Silt is responsible for silting over gravel beds in rivers that are needed by fish for spawning.

Clay- Pores spaces are very small and convoluted

Movement of water and air very slow

•Water holding capacity Tremendous capacity to adsorb water- not all available for plants.

•Chemical adsorption is large

Three main causes of soil erosion:

1.Water2.Wind3.People

Soil erosion: movement of soil from one place to another. Typically from wind or water.

Human activities that increase soil erosion: 1.burning ditches2.ATV use3.logging4.farming5.overgrazing of livestock6.monoculture7.constructuion

Conventional-tillage farming: frequently practiced in midwest. Plowing/disking of fields in fall so it is “ready” in the spring. Leaves topsoil vulnerable for months.Conservation-tillage farming: little or no plowing prior to planting. Leave past crop residue on fields, do not plow in fall.

Terracing: change hillsides into “steps”. Slows water running off.

Contour farming: planting crops across the hill slope instead of up and down. Also slows water

Alley cropping: AKA – agroforestry. Planting crops in alleys between rows of trees or shrubs. Holds soil and reduces evaporation

Cover crops: planting cover crops (alfalfa, clover, etc) immediately after

harvest to hold soil in place over winter.Windbreaks: AKA – shelterbelts. Reduces wind speed, roots hold soil, reduce evaporationStrip cropping: Planting alternating rows of cover crop with row crops. The cover crop traps the soil that erodes from row crop.