Review of 6th Grade Key Terms

Soil Soil provides: housing for animals,

water storage for plants, and minerals

Soil conservation: a method or prevent the soil from erosion and nutrient loss

Mature/ Immature Soil Mature soil: normally has a soil

profile with clearly defined horizons

Immature Soil: doesn’t have any of these properties. This is the soil that has exposed rock, and can never reach the topsoil- (Caused by climate and temperature )

Weathering

Weathering: process by which rock materials are broken down by the action of physical or chemical means

Chemical Weathering

• Process by which rocks break down as a result of chemical reactions

• the agents are water, weak acids, and rain

• acid precipitation and oxidation are examples of chemical weathering

Mechanical Weathering

• Breakdown of rock into smaller pieces by physical means

• The agents are wind, water, ice, gravity, plants, and animals

• Ice wedging and abrasion are forms of mechanical weathering

Erosion/DepositionErosion – the movement of materials

broken down due to the process of weathering- the process by which wind, water, ice, or gravity transport soil and sediment from one location to another

Deposition – the process is which material is laid down

Dust bowl

• Dust Bowl: during the 1930s, a severe drought occurred in a section of the Great Plains that became known as the Dust Bowl

Sedimentary Rock

Sedimentary Rock: formed by compaction and cementation

Metamorphic Rock

• Metamorphic Rock: formed from heat and pressure

Igneous Rock

• Igneous: formed when rock melts ( magma ), and cools and hardens– * Extrusive ( forms on the Earth’s surface)– * Intrusive ( forms inside the Earth)

Continental Drift

Continental Drift: Wegener’s hypothesis that states that the continents once formed a single landmass, broke up, and drifted to their present location.

Pangaea

• Pangaea: all the continents in one landmass- PROOF - similar fossils on separated landmasses

Tectonic Plates

Tectonic Plates: are always MOVING

Geographic Poles

• Geographic Poles: the north or south points of intersection of the earth’s surface with its axis of rotation – used as reference points for location on the Earth

Fault/Boundaries/Stress

Strike-Slip Fault/Transform Boundary – shearingNormal fault/Divergent Boundary – Tension Reverse Fault/Convergent Boundary – Compression

Sea Floor Spreading

• Sea Floor Spreading: evidence for sea-floor spreading is magnetic reversals ( occurs at a divergent boundary)

Volcanoes

Volcanoes: a vent or fissure in the Earth’s surface through which magma and gases are expelled (resulting in a decrease in global temperature)

EARTHQUAKES

• Occur along the edges of tectonic plates

• P Wave: move in a back-and-forth direction; travels through solids, liquids, and gases

• S Wave: a seismic move in a side-to-side direction; cannot travel through the parts of Earth that are completely liquid

• Surface Wave: moves up, down, and around

Water Water Cycle:

evaporation, condensation, precipitation, runoff, and percolation

the water cycle is driven by energy from the sun (causes evaporation)

Ocean Water

• Ocean water covers about 71% of Earth’s surface

Tides

• Tides: Tides are caused by the sun and the moon, and they occur in a variety of cycles.

AtmosphereAtmosphere: a mixture of gases that

surrounds Earth

Temperatures at different layers of the atmosphere vary because of the composition of gases in each layer

Troposphere Stratosphere Mesosphere Thermosphere

Smog

Smog: Vehicle exhaust reacts with sunlight and ozone

Density

•density = the ratio of the mass of a substance to the volume of a substance

Air Pressure•air pressure is strongest at the Earth’s surface because more air is above you; as altitude increases, air pressure decreases

Greenhouse Effect

Greenhouse Effect: the warming of the surface and lower atmosphere of Earth that occurs when water vapor, carbon dioxide, and other gases absorb and reradiate thermal energy

Climate

• Climate: the weather conditions in an area over a long period of time- ocean currents effect climate

Hurricane

Hurricane: when warm and cold fronts meet over warm water

Tornado

•Tornadoes: a funnel cloud that “pokes” through the bottom of a cumulonimbus cloud and hangs in the air