Seasons, Solar Intensity, and Latitude

1. Seasons, Solar Intensity, and Latitude • Factors that affect solar energy: Earth’s rotation, Earth’s revolution around the sun, tilt of the Earth’s axis, and atmospheric conditions. • Summer: greatest solar radiation, occurs in the Northern Hemisphere. • Winter: hemisphere is tilted away from the sun. • Earth is closer to the sun in the Northern Hemisphere during the winter than in the summer.

2. Soil • Thin layer: basic natural resource and deeply affects every other part of the ecosystem. • A good soil for growing most plants should have about 45% minerals( mixture of sand, silt, and clay), 5% organic matter, 25% air, and 25% water. • Soils develops in response to several factors: Parent material, Climate, Living organisms, Topography. Page 73.

3. Soil Components • Clay: Very fine particles. Low permeability to water, therefore, upper layers become waterlogged. • Gravel: course particles. Consists of rock fragments. • Loam: equal mixture of clay, sand, silt, and humus. Rich in nutrients. • Sand: Sedimentary material coarser than silt. Water flows through quickly for most crops. • Silt: Sedimentary material consisting of very fine particles between the size of sand and clay.

4. Organic vs Inorganic Fertilizers • Three common forms: manure, green manure, and compost. Improves soil texture, adds organic nitrogen, and benefits bacteria and fungi. • Improves water holding capacity of soil. • Helps prevent erosion

5. Inorganic Fertilizers • Does not add humus to soil, less ability to hold water. • Lowers oxygen content of the soil • Supplies a limited number of nutrients, usually nitrogen and phosphorus. • Requires large amount of energy to produce, transport, and apply. • Releases nitrous oxides, a green house gas.

6. Soil food web • A community of organisms living all parts of their soil. Describes a complex living system in the soil and how it interacts with the environment, plants, and animals. • See diagram on p. 76

7. Erosion • Movement of weathered rock or soil from one place to another. Caused by flowing water, wind and human activities. • Examples: deforestation, construction and burning of natural vegetation. • Poor agricultural techniques also lead to significant droughts.

8. Three Types • Sheet erosion: soil moves off as a horizontal layer • Rill erosion: fast flowing water cuts channels in the soil • Gully erosion: extreme case of rill erosion, where over time, channels increase in size and depth.

9. Soil erosion • Look up the following definitions: • Desertification • Salinization • Waterlogging

10. Landslides and Mudslides • Landslides: occur when masses of rock, earth, or debris move down a slope. • Mudslides: common type of fast moving landslide that tends to flow in channels. They are caused by disturbances in the natural stability of a slope. • Mudslides usually begin on steep slopes and can be triggered by natural disasters.

11. Areas affected by landslides and mudslides • Where wildfires and construction have occurred • Steep slopes and bottom of slopes and canyons. • Construction of buildings and roads. • Channels along streams or rivers. • Surface runoffs .

12. Review notes • Majority of the rock in the Earth’s surface. • Know examples of igneous rocks, metamorphic, and sedimentary. • Acid rain and its effect on soil. • Types of soils and its amount • Examples of volcanoes, Earthquakes, Tsunamis, and Erosion • Know the different types of plates. • Dust Bowl of 1930’s, geological times ( Paleogene, Neogene, Jurassic, Cretaceous, and Permian). • Types of Rocks (sedimentary, metamorphic, and Igneous) • Elements in the Earth’s crust. • Make sure to identify the A,B,C,D, and O layers. • Review the different types of waves, richter scale, and seismogram. • Study the St. Andreas Fault and Mt. St. Helen. • Topics for the essays: Plate Tectonics, mudslides, landslides, earthquakes, tsunamis, parts of the earth’s crust, hot spots, lithosphere, asthenosphere, and sea floor spreading. • Study the three different types of boundaries( transform, divergent, and convergent),