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Warm up

3 Facts learned yesterday1.2.3.

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A Living PlanetThe geography and structure of the earth are continually being

changed by internal forces, like plate tectonics, and external forces, like the weather which affects all living inhabitants.

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Section 1: The Earth Inside and Out

• The earth is the only habitable planet in the sun’s solar system.• The drifting of the continents shaped the world we live in today.• Earth: Continental Puzzle

– The seven continents on earth fit together like a jigsaw puzzle – Francis Bacon (1620) first to suggest 7 continents were once one

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The Structure of the Earth

Matters of Size• Circumference of the earth: about 24,900 miles• Diameter of the earth: about 7,900 miles Inside the Earth • The core is the center of the earth; made up of iron, nickel• Outer core is liquid; inner core is solid• The mantle surrounds the core:

- has several layers- contains most of Earth’s mass

- Magma—molten rock that forms in the mantle - Crust—thin layer of rock at Earth’s surface

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Inside the Earth

On and Above the Earth • Atmosphere is the layer of gasses surrounding the earth:

1. contains oxygen2. protects Earth from radiation, space debris3. is the medium for weather and climate

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On and Above the Earth

The Layers of the Earth• Atmosphere- layer of gases surrounding the Earth• Lithosphere—solid rock portion of Earth’s surface, forms ocean floor • Hydrosphere—water elements on Earth including atmospheric water• Biosphere—atmosphere, lithosphere, hydrosphere combined

– Plants and animals live within biosphere

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Continental Drift

• Continental Drift—1912 hypothesis of Alfred Wegener:

• Earth once one supercontinent; Wegener calls it Pangaea, “all earth”

• Pangaea splits into many plates that slowly drift apart

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Warm up

List one layer of the Earths surface and what is located on it.

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Section 2: Bodies of Water and Landforms

• Water covers about three-fourths of the earth’s surface.

• The earth’s surface displays a variety of landforms.

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Bodies of WaterOcean Motion

- The ocean circulates through currents, waves, tides- Salt water- Currents act like rivers flowing through the ocean- Waves are swells or ridges produced by winds- Tides are the regular rising and falling of the ocean

- created by gravitational pull of the moon or sun- Motion of ocean helps distribute heat on the planet

- winds are heated and cooled by ocean water

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Hydrologic Cycle- Hydrologic Cycle—cycle of water between atmosphere, oceans, earth

- Water is always recycles

Lakes, Rivers, and Streams- Lakes hold more than 95% of the earth’s fresh water- Freshwater lakes, like the Great Lakes, are result of glacial action- Saltwater lakes form when outlet to sea is cut off:

- streams and rivers carry salts into lake- salts build up with nowhere to go

- Rivers and streams carry water to and from larger bodies of water- Tributaries are smaller rivers, streams that feed into larger ones- Drainage basin—area drained by river and its tributaries

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Ground Water- Ground water—water held in the pores of rock- Water table—level at which the rock is saturated

Landforms- Landforms are naturally formed features on Earth’s surface

Oceanic Landforms- Continental shelf—sea floor from continent’s edge to deep ocean- Sea floor has ridges, valleys, canyons, plains, mountain ranges- Islands are formed by volcanoes, sand, or coral deposits

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Landforms

Continental Landforms• Relief—difference in landform elevation from lowest to highest point• Four categories of relief—mountains, hills, plains, plateaus• Topography—the configurations and distribution of landforms• Topographic map shows vertical dimensions, relationship of landforms

(freedictionary.com. August, 2012.)

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Lets’ Review

Directions: Refer to the landform map on page 34 and in the space provided create/sketch your own Island with eight landforms you believe would be on your island based on the location you chose for it. The Landforms and their locations all must make since with one another, and be based on the location of the island, and what other features may be around it.

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Warm up

List two landforms found in Georgia

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Section 3: Internal Forces Shaping the Earth

• Internal forces reshape the earth’s surface.• Internal forces shaping the earth often radically alter the lives of people as well.

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Plate Tectonics

The Earth Moves• Tectonic plates are massive, moving pieces of Earth’s lithosphere• Plates rises above circulating, heated rock• Geographers study plate movements to understand:

- how the earth is reshaped- how earthquakes and volcanoes are formed

(Enchanted learning.com. August, 2012.)

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Plate Movement• Plates move in one of four ways:

- divergent: by spreading, or moving apart- subduction: or diving under another plate- collision: or crashing together- Transform: sliding past each other in a shearing motion

(Enchanted learning.com. August, 2012.)

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• Movement of plates affects the surface of the earth• Three types of boundaries mark plate movement:

- divergent boundary: Example: Saudi Arabia–Egypt’s plates are spreading apart, the Red Sea making it wider

- convergent boundary: Example: India’s plate is crashing into Asian continent, and building up the Himalayas

- transform boundary: Example: San Andres Fault in California

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Folds and Faults• Two plates meeting can cause folding, cracking of rock• Fault occurs when pressure causes rock to fracture, or crack• Fault line is place where plates move past each other

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Consequences of Plate Movement

• Earthquakes• Tsunamis• Volcanoes

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EarthquakesCause: plates passing each other at a faultEffects

- landslides- land displacement- fires (broken gas lines)- collapsed buildings

Facts• Location in the earth where an earthquake begins is called the focus• Epicenter—the point directly above focus on the earth’s surface

-Nearly 95% of earthquakes occur around epicenter• Richter Scale—measures earthquakesPacific Rim vulnerable to earthquakes

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TsunamiCause: earthquakesEffects: landslides, destruction of property, deathFacts: a giant ocean wave, begins at epicenter of an earthquake:

- travels at up to 450 mph- waves of 50–100 ft. or higher

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VolcanoesCause: Magma, gases, and water collect in underground chambers and the materials pour from crack in the earth’s surface

Effects: volcanic ash produces fertile soil, hot springs are tapped for heat energy, destruction, magma that has reached the earth’s surface (Lava); may create landform

Facts: Most volcanoes occur at tectonic plate boundariesRing of Fire—zone around rim of Pacific Ocean:

- meeting point of eight tectonic plates- vast majority of the earth’s active volcanoes located here

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Warm up

Why do earthquakes and volcanoes occur along the ring of fire?