GeographyChapter 2A Living Planet

Bodies of Water and Landforms Continents – land masses above water Francis Bacon in 1620 proposed the idea

of a supercontinent

http://upload.wikimedia.org/wikipedia/commons/8/8e/Pangea_animation_03.gif

Bodies of Water and Landforms Earth 3rd planet from 93 million miles

from the sun Solar system – sun and nine known

planets as well as other bodies that orbit the sun

Comets – spheres covered with ice and dust that leave vapor trails

Asteroids – large chunks of rocky material

Bodies of Water and Landforms 24,900 miles around (page 28) 7,900 miles in diameter Core – center of the earth made of iron and

nickel Outer core is liquid and inner core is solid

Mantle – contains several layers of earth’s mass

Magma – molten rock Crust – thin layer of rock at the earth’s

surface

Bodies of Water and Landforms Atmosphere – layer of gases

surrounding the earth Oxygen, radiation prevention, debris

blocked, provides weather Lithosphere – solid rock portion of the

earth’s surface including the crust and upper mantle (seafloor as well)

Bodies of Water and Landforms 7 continents

1. North America 2. South America 3. Europe 4. Asia 5. Africa 6. Australia 7. Antarctica

Bodies of Water and Landforms Hydrosphere – water elements of earth –

oceans, seas, rivers, lakes and water Biosphere – part of the earth where

plants and animals live Continental drift – the earth was once a

supercontinent that divided and slowly drifted apart (Pangaea – all earth)

Bodies of Water and Landforms Water helps distribute heat. Oceans cover 71% of planet and are

interconnected Atlantic, Pacific, Indian and Arctic

(Southern Ocean) Currents, waves and tides (gravity) Heat distributed by winds

Bodies of Water and Landforms Hydrologic cycle – continuous circulation

of water between atmospheres, oceans and the earth

Landforms – Review Page 34 & 35

Bodies of Water and Landforms Oceanic Landforms – similar to landforms on

above water Continental shelf – earth’s surface from the edge

of a continent to the deep part of an ocean Continental Landforms – page 34 and 35

Relief – difference in elevation from the lowest point of a landform to the highest(mountains, hills, plains and plateaus

Topography – surface shape and composition of landforms along with their distribution in a region

Internal Forces Shaping the Earth Plate tectonics – Rock heats, rises, cools and

circulates downward, plates or large portions of earth move on top (Map page 37)

1. Plates move apart 2. Subduction – one plate moves under

another 3. Collision or moving into each other 4. Shearing or slide past each other

Internal Forces Shaping the Earth San Andreas fault in CA Rocks fold and crack Fault – when rock cracks under pressure Earthquake – earth shakes or trembles

as plates move (1000s every year) Seismograph – measures the size of

waves created by an earthquake

Internal Forces Shaping the Earth Epicenter – point above the focus of the

earthquake 95% of quakes occur along plate boundaries Pacific rim and southern Asia and Europe are

most vulnerable Aftershocks – smaller magnitude quakes Richter Scale – measure of the amount of

energy released by a quake 8.9 in 1986 is strongest ever measured

Internal Forces Shaping the Earth Tsunami – giant wave in the ocean Volcano – magma and materials (lava,

gas, ash, rock and dust) pouring out of the earth along plate boundaries

Lava – magma that reaches the surface Eruptions hard to predict Ring of Fire – zone around the rim of the

Pacific Ocean where most active volcanoes exist

Internal Forces Shaping the Earth Hot springs and geysers Old Faithful Reykjavik, Iceland Ash can be fertile Hot springs can be used for energy

External Forces Shaping the Earth

Weathering – physical and chemical processes that change the characteristics of rock on or near the earth’s surface

Sediment – mud, sand, or silt particles of rock

Mechanical weathering – doesn’t change composition just size

Chemical weathering – rock changed into new substance with interaction of elements, air and water

External Forces Shaping the Earth

Erosion – weathered material moved by wind, water, ice or gravity

Reshapes landforms Water moves material, abrases material

or dissolves it Streams erode vertically and

horizontally Deposit material in deltas

External Forces Shaping the Earth

Wind erosion – dunes, sediment moved by wind

Loess – fertile land from windblown silt and clay

Glacier – changing of landforms by moving ice (Ice Age 3)

Moraine – rocks deposited by glaciers

External Forces Shaping the Earth

Soil – loose mixture of weathered rock, organic matter, air and water that supports plant growth

Fertility – ability to nurture plants 5 factors affecting soil

1. Parent material 2. Relief 3. Organisms 4. Climate 5. Time

Variety of soils and climates determine vegetation (bananas)