CHAPTER 1
SECTION 2
THE EARTH IN SPACE
Ø Made up of the sun, Earth, and nine other planets as well as moons, comets and asteroids
Ø All orbit the sun
Ø Two types of planets-small and solid; large and full of gas
Ø Atmosphere-layer of air which surrounds the Earth- containing nitrogen and oxygen
Ø Earth-takes 24 hours to make one complete spin on its axis
Takes 364 ¼ days to orbit or make one revolution around the sun
Ø Earth is tilted at 23 ½ degrees-why we have seasons
Ø Summer solstice-when the Northern Hemisphere receives the most amount of sunlight (directly over the Tropic of Cancer)
Ø Winter solstice-when the Northern Hemisphere receives the least amount of sunlight (directly over the Tropic of Capricorn)
Ø Equinoxes-sun is directly over the Equator
CHAPTER 1
SECTION 3
FORCES SHAPING THE EARTH
1. INSIDE THE EARTH
Ø Made up of three layers
Core-hot iron mixed with other metals and rocks
Mantle-layer of rock surrounding the core
Crust- upper layer of the earth. Includes the ocean floor and continents
Ø Magma-melted rock flows from a volcano
2. FORCES BENEATH the EARTH’S CRUST
Ø Plate Tectonics-earth’s crust is made up of plates-pull away from each other, push against each other, slide alongside each other
Ø Earthquakes-pressure causing plates to move suddenly. Underwater earthquakes-cause tsunamis.
Ø
Plates moving alongside each other create cracks
called faults
Ø Weathering- breaking of surface rock into boulders, gravel, sand, and soil. Water, frost, chemicals, and plants can cause weathering
Ø Erosion-process of wearing away or moving the weathered material. Can be caused by water, wind, or ice.
Ø Glaciers-giant sheets of ice
CHAPTER 1
SECTION 4
LANDFORMS AND WATERWAYS
1. TYPES OF LANDFORMS
Ø Mountains-1000 feet or more, rugged, steep slopes
Ø Hills-lower with rounded tops
Ø Valleys-lie between mountains and hills
Ø Canyons-steep-sided lowlands that rivers have cut through a plateau
Ø Plains-low-lying stretches of flat or gently rolling land
Ø Plateaus-flat, have higher elevation than plains
Ø Isthmus-piece of land that connects two larger pieces of land
Ø Peninsula-water on three sides, longer coastline than a cape
Ø Continental shelf-plateau that stretches for several miles underwater
Ø Trenches-valleys on the ocean floor. Lowest spots on the earth’s crust
2. BODIES OF WATER
Ø Over 70% of the earth is covered by water. Most is salt water
Ø Strait-body of water between two pieces of land and connects two larger bodies of water
Ø Channel-body of water between two pieces of land and connects two larger bodies of water- channel is wider than a strait