EARTH SCIENCE Science Earth Sciences What Is Studied Photo Physical Geography Patterns and processes including weathering and erosion Limnology Inland waters including lakes ponds rivers streams wetlands and groundwaters Meteorology Atmosphere including the weather Oceanography Oceans and seas Paleontology Fossils and prehistoric life W H A T I S E A R T H S C I E N C E 5
6 W H A T I S E A R T H S C I E N C E EARTH SCIENCE The Earth’s shape is almost round like a ball or sphere But unlike a ball the Earth is made of different parts Scientists call these parts Earth’s spheres The four spheres are the lithosphere hydrosphere biosphere and atmosphere Hydro means water Can you guess what part of Earth makes up the hydrosphere The hydrosphere includes all forms of water under on and above Earth Atmosphere Hydrosphere Biosphere Lithosphere This photo shows all four Earth spheres Atmosphere air Hydrosphere water Biosphere life Lithosphere land Earth’s Spheres ScienceWhat Is Studied Photo PedologySoil VolcanologyVolcanoes lava magna Earth Sciences
7 EARTH SCIENCE W H A T I S E A R T H S C I E N C E The Earth’s Hemispheres We call the top half of the Earth the Northern Hemisphere and the bottom half the Southern Hemisphere The equator is an imaginary line around the middle of Earth’s surface separating the Northern Hemisphere from the Southern Hemisphere At the top of the Northern Hemisphere is the North Pole The South Pole is at the bottom of the planet in the Southern Hemisphere The closer you live to the equator the warmer your climate And the further away from the equator you live the colder your climate is Another imaginary line runs through the center of the Earth from the North Pole to the South Pole We call this line Earth’s axis The axis tilts at 23 45 degrees Earth rotates around the axis The tilt of Earth’s axis is why our seasons change The seasons in the Southern Hemisphere are opposite of the seasons in the Northern Hemisphere If it is winter in the Northern Hemisphere it is summer in the Southern Hemisphere NORTHERN HEMISPHERE SOUTHERN HEMISPHERE EQUATOR In this illustration the sun’s rays shine more directly on the Southern Hemisphere causing those below the equator to experience summer Equator EARTH SUN
8 W H A T I S E A R T H S C I E N C E EARTH SCIENCE The Origin of Our Planet Scientists believe the Earth was created over 4 5 billion years ago It came from a cloud of dust and gas swirling in space Some of the dust and gas formed the sun The rest became planets in the solar system equator i-KWAY-tur an imaginary line around the middle of the Earth pole pohl one of the two points that are farthest away from the equator the North Pole or the South Pole sphere sfihr a solid shape like a basketball or globe Did you know Earth really isn’t a perfect sphere Earth bulges slightly at the equator making the Earth a geoid Earth rotates spins faster at the equator than at the poles because the poles are closer to Earth’s axis This is what causes the bulge The Sun is the star closest to Earth Months approximate range Northern Hemisphere Season Southern Hemisphere Season December January FebruaryWinter Summer March April MaySpring Fall June July AugustSummerWinter September October NovemberFallSpring What Season Is It
