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Earth science study guide

Earth’s surface is always changing.  Blowing wind and flowing water cause some changes.  Moving rock deep inside the earth causes other changes.  These processes wear earth’s surface down in some places and build it up in others.

Destructive processes wear down earth’s surface.  Some destructive forces include earthquakes, volcanoes, floods, glaciers, etc.   weathering breaks rocks into smaller pieces, and occurs from wind and rain, and also plants and animals.  Erosion is another destructive process.  The sediment erodes, or is carried away by wind and/or water in the form of rain, ocean waves, or river flow.  Over time, along with gravity, all of these things change the surface of the earth.

• Landforms - a surface feature of earth; ex. mountain

• Destructive processes - processes that wear earth’s surface down

• Weathering - the __break__ing down of rock at or near the earth’s surface

• Sediment - loose particles of weathered rock, including pebbles and sand

• Glaciers - huge sheets of ice that moves slowly over land

• Ice wedging - when ice freezes and thaws over time, it creates cracks in rock

• Erosion - when weathered rock is picked up and moved/takes

• Gravity - a force that pulls objects down

• Earthquake - a shaking of the ground that happens when rock below Earth's surface breaks and moves suddenly

• Volcano - an opening in Earth's surface that lets hot, melted rock and gasses escape

Constructive processes build up earth’s surface.  Rock is weathered (broken down) and eroded (carried away) by wind and water.  But when wind and water slow down, they drop, or deposit, some or all of the rock particles.  This deposition builds up into new landforms.

• Constructive processes - processes that build up earth’s surface

• Deposition - the __drop__ping of rock material by water, wind, or glaciers

• Delta - a flat piece of land made up of sediment deposited by a river near its mouth

• Floodplain - a wide, flat area of land formed from sediment deposited by a river outside its banks

• Dune - hill of sand deposited by wind

• Moraine - a ridge of sediment deposited when a glacier melts

• Fault - a break in the rock that makes up the earth's crust, or top layer

• Magma - melted rock below Earth's surface

• Lava - melted rock that reaches earth’s surface

People use technology to try to control these processes.  Some examples of this are building dams and levees or storm drains to help control flooding,  building sea-walls along the shore to slow erosion, or scientists using technology to study earthquakes.

• Technology - the practical use of science to solve problems

• Flood - overflow of water onto land that is usually dry

• Dam - a structure built across a river to control its flow

• Levee - raised bank of sediment or rocks built along the edges of a river to prevent flooding

• Storm drains - grate and pipe that allow rainwater to flow off roads into a nearby waterway

• Beach nourishment - the process of adding sand to an eroded beach to rebuild it

• Seismologist - scientists who study earthquakes

• Seismic waves - waves of energy that travel through the earth’s crust

• Seismographs - a tool that measures and records seismic waves

• Seismogram - a record of seismic waves made by a seismograph