CONSTRUCTIVE DESTRUCTIVE PROCESSES EARTHQUAKE Earthquakesclick to play video

CONSTRUCTIVE & DESTRUCTIVE PROCESSES

EARTHQUAKE Earthquakes-click to play video Earthquakes happen when the land moves at a fault line http: //studyjams. scholastic. co m/studyjams/science/ro cks-mineralslandforms/earthquakes. htm They’re dangerous, but they also can create new: • coastal plains (plates rise up) • bays or gulfs for harbors (plates rise down) • hot springs and geysers

TSUNAMI An underwater earthquake can cause a tsunami (huge tidal wave)

VOLCANO Volcanoes-click to play video An opening in the Earth’s crust that allows magma from the Earth to flow out (becomes lava) The hardened lava causes new land to form

DEPOSITION Deposition is when bits of eroded rock, soil, and sediment are dropped off/deposited into an area-building up new landforms Deposition-click to play video (1: 18) Most common types of surface features caused by deposition are: Deltas Sand Dunes

DELTA Delta- click to play video (0: 39) A delta is formed through depositionwhen a section of a river(usually at the mouth) slows down so much that it drops off pieces of sediment/sand/rock into one spot

SAND DUNE Sand Dune-click to play video (1: 17) A sand dune is formed when wind blows particles of sand into one place, forming a hill of sand

FLOODS Overflow Can of water that covers land destroy land habitats Can deposit nutrients on land so the nutrients help for farming http: //www. youtube. com/watch? v=sr. Vv. C 98 sax Q&feature=related

WHAT IS WEATHERING? Weathering is the process of breaking down of rocks, and parts of the earth’s crust by wind, water, ice, plants, animals, or chemical changes. There are 2 types of weathering: Mechanical Chemical

EROSION The process by which water, ice, wind or gravity moves fragments of rock and soil.

WEATHERING VS. EROSION http: //studyjams. scholastic. com/studyjams/ja ms/science/rocks-mineralslandforms/weathering-and-erosion. htm Listen carefully for the quiz!

MORE ABOUT WEATHERING

What is Mechanical Weathering MECHANICAL WEATHERING IS THE PROCESS OF BREAKING DOWN ROCKS INTO SMALLER PIECES. ONLY THE SIZE OF THE ROCK CHANGES, NOT ITS CHEMICAL COMPOSITION. IT CAN BE CAUSED BY 5 COMMON WAYS: - TEMPERATURE CHANGES ICE WEDGING GRAVITY ABRASION - PLANTS AND ANIMALS

Mechanical Weathering by Temperature ROCKS GET HOT IN THE DAY, COOL AT NIGHT. THIS REPEATED CYCLE CAN CAUSE ROCKS TO PEEL OR FLAKE.

Mechanical Weathering by Ice Wedging WATER MAY GET INTO A SMALL CRACK IN THE ROCKS. WHEN WATER FREEZES, IT EXPANDS AND THE CRACK GETS BIGGER. WHEN THE WATER MELTS, IT GOES DEEPER IN THE BIGGER CRACK AND REFREEZES. EVENTUALLY, THE ROCK WILL BREAK INTO SMALLER PIECES.

Mechanical Weathering by Gravity LANDSLIDES MOVE DOWNHILL DUE TO THE GRAVITY OF THE EARTH. AS THE ROCKS FALL DOWN, THEY COLLIDE AND BREAK INTO SMALLER PIECES

Mechanical Weathering by Abrasion GLACIERS & ICE, WATER AND WIND BLOWN SAND CAN CONSTANTLY RUB AGAINST ROCKS AND BREAK THEM DOWN. THIS IS CALLED ABRASION.

Mechanical Weathering by Plants and Animals • Plant and Tree Roots - Plants and trees growing in rocks can cause rocks to break down into smaller rocks. • Burrowing - Weathering can also be caused by animals burrowing into the rocks, soil to make their home. • Lichens, and Plant & Animal Acids - Lichens, which are combinations of fungi and algae, live on rocks and slowly eat away at the surface of rocks. When plants and animals die and decay, they produce organic acids which dissolve rocks. • People – People change rocks by excavating, digging, mining, and construction.

What is Chemical Weathering? CHEMICAL WEATHERING IS THE PROCESS OF INTERACTION OF MINERALS IN ROCKS WITH CHEMICALS IN WATER OR AIR. SOME EXAMPLES OF CHEMICAL WEATHERING ARE: - OXIDATION - CARBONATION - HYDRATION

Chemical Weathering by Oxidation OXIDATION HAPPENS WHEN MINERALS ON THE SURFACE OF THE ROCKS REACT WITH OXYGEN IN THE AIR FORMING AN OXIDE (LIKE IRON RUSTING) AND BREAK INTO SMALLER ROCKS OR SOIL LIKE SUBSTANCE.

Chemical Weathering by Carbonation CARBONATION HAPPENS WHEN CARBON DIOXIDE IN THE AIR MIXES WITH WATER IN THE RAIN. IT FORMS A WEAK ACID CALLED CARBONIC ACID. THIS WEAK ACID RAIN REACTS WITH MINERALS IN ROCKS TO DISSOLVE THEM.

Chemical Weathering by Hydration HYDRATION IS WHEN ROCKS ABSORB WATER AND BREAK INTO SMALLER PIECES DUE TO EXPANSION, AND EVAPORATION.

MORE ABOUT EROSION

WATER EROSION Rivers, streams, and runoff

ICE EROSION Glaciers

WIND EROSION

MASS MOVEMENTS Landslides, mudslides, slump and creep landslide clip. mpeg