LITHOSPHERE Solid, rocky crust covering entire planet. http://mediatheek.thinkquest.nl/~ll125/images/struct.jpg
ATMOSPHERE The air surrounding Earth • 78% Nitrogen • Just under 21% Oxygen • less than 1% argon, carbon dioxide & other gasses www.space.gc.ca
HYDROSPHERE All the water in or near the Earth
BIOSPHERE Composed of all living organisms • Plants • Animals • One-celled organisms
The 4 Geo-spheres” of the earth are all interconnected akjdfajdfljadsfjaljdflajdfljalsfjaljflajfljaldfjafjfjjfjf http://www.uwsp.edu/geo/faculty/ritter/images/misc/spheres3.jpg
Layers of the Earth
Inner Core The super-hot solid inner layer of iron and nickel under extreme pressure
Outer Core The liquid layer of melted iron and nickel that surrounds the inner core.
Mantle The thickest layer. This layer is made up of hot, dense rock – silicon, aluminum, iron, magnesium, and oxygen. This layer rises, cools, sinks, warms up, rises, etc.
Crust lithosphere The rocky shell that covers the earth’ surface. The shell is broken up into plates that move apart or ground together to push up mountains, create volcanoes, and produce earthquakes.
Internal Forces of Change
Continental Drift The theory that the land of the earth was once connected as one large super continent (Pangaea) and has moved “drifted” to its current locations (still moving) Plate Tectonics The theory that the crust of the earth is broken up into plates (8 major and many minor) that “float” on the mantle
Subduction – When a sea plate and continental plate collide, the heavier sea plate DIVES under the lighter continental plate. The sea plate then is heated and becomes magma which escapes through volcanoes.
Accretion – slow process that occurs when a sea plate SLIDES under a continental plate. This causes debris which makes continents grow outward.
Spreading – When sea plates pull apart leaving a rift, or deep crack. Magma wells up between the two plates to make underwater volcanoes and ridges.
Folding – when moving plates squeeze the earth’s surface until it bends the layers of rock.
Faulting - When moving plates grind past each other, creating cracks in the curst.
Earthquake – sudden, violent moving of plates along a fault where built up pressure suddenly snaps and shifts.
Ring of Fire – area along the edge of the Pacific Ocean that is a zone of frequent earthquakes and volcanoes.
Volcano – mountains formed by lava (magma) that breaks through the earth’s crust.
Click on the underlined headings to see animation: Spreading (ocean) Oceanic Divergent Plates Spreading (continental) Continental Divergent Plates Subduction & Accretion (continental-oceanic) Convergent Continental-Oceanic Plates Subduction & Accretion (ocean) Convergent Oceanic Plates Folding & Faulting Convergent Continental Plates Transform Fault transform fault
External Forces of Change
Weathering – process that breaks down rocks on the earth’s surface into smaller pieces Physical Weathering – Form of weathering that occurs when large masses of rock are broken down into smaller pieces. Example: Cracks in rocks fill with water and then freeze. Ice expands and cracks the rocks.
Chemical Weathering – Form of weathering that occurs when the make-up of the rock is changed by transforming minerals or combining with new elements. Example: carbon dioxide in the air dissolves limestone.
Erosion is the wearing away of the earth’s crust by water, wind, and glaciers. Wind erosion – movement of dust, sand, and soil from one area to another. Plants help prevent this.
Glacial erosion – large bodies of ice move slowly across the earth’s surface. As the glaciers move they pick up rocks and soils in their path. As the glacier retreats it can also leave fields of debris behind.
Water erosion – fast-moving water cuts into the land as it flows downstream. Ocean waves can also erode coastal cliffs. WATER is the most significant cause of erosion.
Continental Shelf The part of a continent that extends under the water.
Lowest Point on dry land – shore of the Dead Sea, 1,349 below sea level
Water cycle – the regular movement of water from ocean to air to ground and back to the ocean.
Sublimate – ice and snow can turn from solid directly into water vapor (skipping liquid form)
Evapotranspiration – water transpired from plants and evaporated from the soil
sleet Precipitation – moisture that falls to earth in the forms of snow, sleet, hail, and rain.
Ice caps and glaciers – store frozen water for thousands of years. 2% of all the world’s water is frozen freshwater.
Surface runoff – water flow that occurs from excess water from rain, meltwater, or other sources that flow over the land.
Freshwater storage – accumulation of runoff, stream flow, and other fresh water (lakes)
Infiltration – downward movement of water through soil. Ground water – water under the earth’s surface from rain, melted snow, lakes, and rivers (freshwater – not salt water).
Aquifer – underground water -bearing layers of porous rock, sand, or gravel.
desalination The removal of salt from sea water to make fresh water
Parts of a river River – large natural stream of water that runs through the land. HINT: Water never runs naturally uphill. Some rivers run north, but ALL natural rivers run from a high point to a low point – ALWAYS
Source – place where a river or stream begins, usually in the highlands. Lake Itasca