Ch. 2 “A Living Planet”

Ch. 2.1 “The Earth Inside and Out”

The Solar System

• Nine (Eight) planets and other celestial bodies that revolve around a sun

• Earth is 3rd planet

Earth’s Structure

• Core: solid, very hot, made of iron and nickel

• Mantle: molten rock aka. magma

• Crust: made of tectonic plates

• Plates that rise above ocean waters form the 7 Continents

Above Ground

• Atmosphere: layer of gases that surround earth

• Lithosphere: solid rock surface

• Hydrosphere: water elements

• Ecosphere/Biosphere: plants and animals

“Continental Drift Theory”

“Sea Floor Spreading”

• One of the causes continental drift.

• Occurs over millions of years

Ch. 2.2 “Bodies of Water and Landforms”

Oceans and Seas

• Oceans: interconnected body of salt water

• Covers 71% of planet• 3 basic motions:

– Current– Waves – Tides

Lakes, Rivers, Streams

• Lakes:– Hold 95% of all fresh

water– Can be both fresh and

salt water (Great Salt Lake)

• Rivers and Streams feed water to oceans and lakes

• Drainage basin: area drained by rivers and streams

“Hydrologic Cycle”

• Continuous circulation of water between the:

1. Oceans, Lakes

2. Atmosphere

3. Earth

Ground Water

• Water that is held in pores of rock

• Water table– The level at which the

rock is saturated

Landforms

• Naturally formed features on the earth

• 2 kinds:

1. Oceanic

2. Continental

Oceanic Landforms

• Seafloor has same features except below water

• Continental Shelf: edge of continent to deep part of ocean

Continental Landforms

• Relief: difference in elevation from lowest to highest point

Ch. 2.3 “Internal Forces that shape the earth”

Plate Tectonics

• Pieces of earths crust that float on magma• Interaction of plates is what shapes the earth

Plate Boundaries

• Plate Boundaries: where plates come in contact with one another

– 3 Types1. Divergent

2. Convergent

3. Transform

Divergent boundary

• plates move apart or spread

• Example is sea floor spreading

Convergent Boundary

• Plates collide and either:1. Dive under

one another

2. Rip up• Fault: fracture in the

earths crustFig 2

Fig 1

Transform boundary

• Plates slide past one another

• Earthquake: violent movement of plates

Earthquakes

• Epicenter: surface mark of quakes beginning

• Richter scale: measures amount of energy released by an earthquake.

• Tsunami: giant wave

Volcanoes

• Where magma (lava) pours out of earth onto the surface

• Ring of Fire: volcanic zone around the rim of Pacific Ocean

Ch. 2.4 “External Forces Shaping the earth”

Weathering

• The mechanical-(physical) and chemical process that changes earth

– Break down rock to form sediment

• 2 forms:

A. Mechanical B. Chemical

Mechanical Weathering

• Process that breaks rock into smaller pieces

• Ice crystals, plant roots, drilling are all examples

Chemical Weathering

• When rock is changed into new substance after reacting to air or water– Ex: iron rust

Erosion

• The movement of weathered material• 3 Kinds:

A. Water B. Wind C. Glacier

Water Erosion• Movement of material through the motion of

water flow through streams, rivers, ocean currents

-when a river enters the ocean, sediment is deposited in fan-like landforms called deltas

Wind Erosion• Movement of

material through the wind

Deposits• New landforms are

created by loess-– Wind-blown silt and

clay sediment that produces fertile soil.

Glacial Erosion

• Glacier: large, long lasting mass of ice

• Glaciation: changing of landforms by slow moving glaciers – Ridges or hills formed

by glacial rocks are called a moraine.

Building Soil

• Weathering and erosion are part of the process of “building soil”

• Soil is comprised of rock, humus, air, and water

• Humus: organic material