Chapter 2 The Earth

I. Section One Planet Earth

A. Our Solar System The Planets: Neighbors in Space At least 9 exist Mercury, Venus, Earth, & Mars are closest to the sun Earth is about 93 million miles from the sun Earth is 3rd planet from the sun Farthest from the sun are Jupiter, Saturn, Uranus, Neptune, and Pluto Jupiter is the largest Earth ranks 5th in size Pluto is the smallest

Solar System (cont.) Asteroids, Comets, and Meteoroids Asteroids are small, irregularly shaped objects Comets are made of icy dust particles and frozen gases (have tails) Meteoroids are pieces of space debris Chunks of rock and iron

B. Getting to Know Earth Earth is not a perfect sphere Its wider around the center than from top to bottom The difference is less than 1% Water, Land, and Air About 70% of the earth’s surface is water – hydrosphere About 30% is land – lithosphere Air we breathe (78% nitrogen, 21% oxygen, 1% other) – atmosphere People, animals, & plants that live on the earth - biosphere

Getting to Know Earth (cont.) Landforms Pgs. 14-15 Seven Continents – be able to name these! The part of the continent that extends under water – continental shelf

Getting to Know Earth (cont.) Earth’s Heights & Depths Highest Point – Mt. Everest (South Asia) – 29,035ft Lowest dry land point – Shore of the Dead Sea (Southwest Asia) – 1,349ft below sea level Deepest Depression (under the sea) – Mariana Trench (southwest of Guam) – 35,827ft deep

II. Section Two Forces of Change

A. Earth’s Structure A Layered Planet Three Layers Core (Inner & Outer), Mantle, Crust

Earth’s Structure (Cont.) Plate Movement Many scientists believe that in the past, there was one giant super continent called Pangaea Over millions of years, it broke apart into smaller continents that we know today We will watch the video “Catastrophic Past”

Earth’s Structure (Cont.) The earth’s plates continue to move and cause change, as well as natural disasters Push-up mountains, create volcanoes, & produce earthquakes Plate Tectonics

B. Internal Forces of Change Colliding & Spreading Plates Folds & Faults – know the difference

Internal Forces of Change (Cont.) Earthquakes Ring of Fire – Pacific Ocean – most earthquake-prone areas on the planet Volcanic Eruption Also occurs along the Ring of Fire

C. External Forces of Change Weathering Break down of rocks into smaller pieces Wind Erosion Movement of dust, sand, & soil Glacial Erosion Water Erosion From rain, rivers, streams, & oceans

III. Section III Earth’s Water

A. Water Cycle 4 Stages Evaporation Condensation Precipitation Run-off/Groundwater Although these stages work in a continuous motion, please learn them in this order!

B. Bodies of Salt Water Oceans Seas, Gulfs, and Bays About 97% of the earth’s water is found in the oceans! 4 Oceans – Know These! Seas, Gulfs, and Bays Ocean Water to Drinking Water 97% of the world’s water is too salty for us to use Desalination is the process of removing salt from the water so we can use it.

C. Bodies of Freshwater 3% of the earth’s water is freshwater 2% (of this 3) is frozen in glaciers Another .5% is underground What does that leave us? Lakes, Streams, and Rivers Groundwater Important source of water (sometimes found in wells)