An earthquake is a shaking of the ground due to the sudden movement of rocks beneath Earth’s surface Earth’s outer layer is called the crust This rock shell ranges from about 3 to 44 miles 5 to 70 km thick The crust is the top part of a larger layer called the lithosphere This layer is made of numerous large sections called plates Earth’s plates fit together like puzzle pieces UNEARTHlNG EARTHQUAKES A QUAKE CAN LAST FOR A FEW SECONDS OR IT CAN LAST FOR SEVERAL MINUTES IT MIGHT BE A LIGHT RUMBLE THAT YOU BARELY NOTICE OR FURNITURE CAN MOVE AND OBJECTS CAN FALL OFF WALLS AND SHELVES IN MORE SERIOUS QUAKES THE GROUND CAN CRACK OPEN AND BUILDINGS CAN TOPPLE 6
7 EARTH IS MADE OF FOUR MAJOR LAYERS THE CRUST THE MANTLE THE OUTER CORE AND THE INNER CORE PLATE ONE OF THE LARGE PIECES OF ROCK THAT MAKE UP EARTH’S OUTER LAYER LOOK INSIDE THE EARTH CRUST MANTLE OUTER CORE INNER CORE
The lithosphere floats on a layer of soft hot rock The plates can drift away from each other leaving gaps They can also push against each other slide past one another or slide under or over each other These movements create tremendous pressure between the plates PRESSURE A FORCE THAT PUSHES ON SOMETHING ELSE EARTH'S CONTINENTS Arctic Ocean EURASIA NORTH AMERICA EURASIA NORTH AMERICA PANGEA Pacific Atlantic Ocean Ocean AFRICA SOUTH AMERICA AFRICA Tethys Ocean SOUTH AMERICA INDIA Indian Ocean ANTARCTICA AUSTRA Southern Ocean ANTARCTICA GEOLOGISTS OR SCIENTISTS WHO STUDY EARTH AND ITS HISTORY THINK THAT EARTH'S LAND WAS GROUPED INTO ONE SUPERCONTINENT CALLED PANGEA ABOUT 250 MILLION YEARS AGO IT TOOK MILLIONS OF YEARS FOR THE PLATES MAKING UP THE SUPERCONTINENT TO DRIFT 8 APART IN TIME FORMING THE SEVEN CONTINENTS WE KNOW TODAY
9 EARTH'S PLATES Have you ever tried to stop someone bigger from getting past you It probably wasn't easy Earth's plates are very big and they don't want to stop moving Two plates create a lot of force when they crash into each other slide past each other or slide over or under each other Different things can happen where two plates meet One may slide under the other Sometimes plates fold under the pressure rising up to make mountains These movements don't happen quickly Pressure builds up between plates over hundreds of years When two plates suddenly slip and release this pressure the energy let loose causes an earthquake TECTONIC PLATES North american plate Eurasian plate Juan de fuca plate North american plate Caribbean Arabian plate Indian Date Philippine plate Pacific plate African plate Pactic plate plate Cocos plate South america plate Nazca plate Indo Australian plate Scotia plate Antarctic plate Antarctic Plate THIS MAP SHOWS EARTH'S MAJOR AND MINOR PLATES THERE ARE ABOUT 15 TO 20 TECTONIC PLATES OR MOVEABLE MASSES OF ROCK THAT MAKE UP EARTH'S CRUST
