A Living Planet

CH 2 PHYSICAL GEOGRAPHY

SECTION 1: THE EARTH INSIDE AND

OUT

Solar System Our sun is a medium-sized star on edge of

the “Milky Way” Galaxy Earth, 1 of 8, 93m miles away from Sun Asteroids – large chunks of rocky material

Asteroid belt between Jupiter and Mars Atmosphere: layer of gases

Provides oxygen; protects Earth from radiation and space debris; provides the medium for weather and climate

Lithosphere: 30-90m; solid rock Hydrosphere: water (oceans, seas, rivers,

lakes, etc.) Biosphere: atmosphere, lithosphere, and

hydrosphere

EARTH: OUTSIDE

24,900m circumference, 7,900m diameter Three divisions…

Core: center of the Earth, made up of iron and nickel; outer portion is solid, inner portion liquid

Mantle: most of Earth’s mass Crust: thin layer (19-37m) of rock at the Earth’s surface

Continents Landmasses above water on Earth 7: North America, South America, Europe, Asia, Africa, Australia,

Antarctica Connected?

Francis Bacon (English) first to conceive their previous connection as a supercontinent in 1620

Rocks found in South America & Africa match, supporting this idea Continental Drift

Alfred Wagner (Germany) – 1912: posited hypothesis Pangaea (“all earth”), surrounded by Panthalassa began to split apart 65m yrs ago

EARTH: INSIDE

Bodies of Water Ocean – covers 71%

Atlantic, Pacific, Indian, Artic (sometimes considered part of the Atlantic)

Ocean motion Currents – like rivers flowing through the ocean Waves – affect of wind on surface Tides – gravitational pull of sun/moon; regular

rise and fall Winds – moderate temp. over land after blowing

over water Hydrologic Cycle

Continuous circulation of water between atmosphere-ocean-earth

Lakes 95% of earth’s fresh water supply Result of glacial action thousands of years ago

Ground water; water table

WATER

SECTION 3: INTERNAL FORCES

SHAPING EARTH

Internal forces reshape the earth’s surface

Internal forces shaping the earth often radically alter the lives of people as well (in-depth look this week)

Plate Tectonics Enormous moving shelf that forms the earth’s crust

(lithosphere) How earthquakes and volcanoes occur

Plate movement (p88)1. Spreading (moving apart)2. Subduction (diving under another plate)3. Collision (crashing into another plate)4. Shearing (sliding past each other)

PLATE TECTONICS

When tectonic plates come into contact, changes on the earth’s surface occur

3 Boundaries that mark plate movements1. Divergent Boundary

- Plates move apart, spreading horizontally- Ex: Saudi Arabia & Egypt = Red Sea wider (part of Great Rift

Valley)

2. Convergent Boundary- Plates collide, plate dives or plates both crumple- Ex: India Asia = Himalayas

3. Transform Boundary- Plates slide past one another- Ex: San Andreas Fault (CA)

PLATE BOUNDARIES

DIVERGENT

CONVERGENT

TRANSFORM

When Plates Meet… Folds & Faults If rock is not flexible, fracture occurs under pressure = fault Fault Line = where plates move past each other

Earthquakes What is it?

Sudden release of energy in the form of motion; Violent movement of the earth caused by plate movement

Focus Location in the earth where it began

Epicenter Point directly above focus on earth’s surface

95% of all earthquakes occur around major plate boundaries Damage

Aftershocks – smaller-magnitude quakes; can occur for days

EARTHQUAKES

Earthquake Richter Scale

C.F. Richter developed a scale to measure amount of energy released (telling us the strength of a quake)

2 not noticeable 4.5 newsworthy 7+ major 9.5 Chile 1960 largest ever recorded

What do we know? Measuring? Yes. Seismograph = detects and measures the

size of the waves Predicting? No.

EARTHQUAKES

Tsunamis A giant wave in the ocean caused by earthquake How powerful? 450mph w/ 50-100 feet waves

Extreme? 1960 Chile damage in Japan Even worse? Japan in March 2011 Deadliest in history? Indian Ocean earthquake of 9.3

Volcanoes Magma (lava) + gas + water = erupt Unpredictable = active/inactive Ring of Fire

Zone around the Pacific Ocean which is home to the majority of active volcanoes; 8 major tectonic plates meet here

Hot springs & geysers Water circulation near magma chambers U.S., Japan, Iceland only --- Old Faithful

INTERNAL FORCES

JAPAN EARTHQUAKE 2011

&

INDIAN OCEAN TSUNAMI 2004

Japan Earthquake Damage? You Betcha… Before & After Aerial Photos: http://

www.nytimes.com/interactive/2011/03/13/world/asia/satellite-photos-japan-before-and-after-tsunami.html

Short video clip highlighting damage: http://www.nytimes.com/video/multimedia/100000000718650/clips-of-the-earthquake-and-tsunami.html

Interactive Map of Damage: http://www.nytimes.com/packages/flash/newsgraphics/2011/0311-japan-earthquake-map/index.html?ref=asia

How Plate Tectonic Movement Caused the Earthquake: http://www.nytimes.com/interactive/2011/03/11/world/asia/maps-of-earthquake-and-tsunami-damage-in-japan.html?_r=0

Tsunamis Stephen Colbert on Tsunami

http://thedailyshow.cc.com/episodes/6o11y2/march-1--2010---neil-degrasse-tyson

Infographic on Tsunami: http://

www.nytimes.com/packages/khtml/2004/12/26/international/20041227_QUAKE_FEATURE.html

WEDNESDAY’S RESOURCES