tsunami

date jueves, 23 de julio de 2009

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the hurricanes and twisters

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Features of earth
Shape and size of earth:
Earth is spherical. The other planets in the solar system are also spherical. But earth is not a perfect sphere. It is flattened at the poles. We call this shape a GEODE.
The surface of earth:
We can see different colors on the surface of earth if we look at it from space. These correspond to there different areas.
*some areas are solid land. These areas are called the “LITHOSPERE”.
Part of the lithosphere is under the oceans.
Other part is above the oceans and some the continents and islands.
There are seven continents
Africa
Asia
Europe
North America
South America
Australia/Oceania
Antarctic
The continents and islands cover a quarter of earth’s surface.
*other areas are covered by water. This is called the “HYDROSPHERE” it includes oceans, seas, rivers, lakes and ice
There are five oceans:
The pacific
The Atlantic
Indian
Artic
Antarctic
The hydrosphere covers three quarters of earth’s surface.
*A large layer of gases surround earths. These gases make up the “atmosphere” nitrogen and oxygen are the main gases in the atmosphere. Meteorological phenomena occur in the lowest part of the atmosphere.
For example: changes in the temperature and storms occur here.
Higher up is ozone layer. This layer stops some of the sun’s rays from reaching earth life on the planet would be impossible if these rays reached earth.
The interior of earth
Earth has three layers:
*the crust: is the surface layer of earth. It is made up of solid material. It is thicker in areas where there are large mountain chains like the Andes.
It is thinner under the oceans.
*the mantle: is the intermediate layer of earth. It is divided into two parts:
-the upper mantle: is made up of solid rock.
-the lower mantle: is partly made up of molten rock.
*the core: is the deepest layer of earth. It is basically made of iron. It is very hot. Some parts of the core are liquid.

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Continental crust is thicker and less dense and oceanic crust is thinner and more dense.

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