Ch. 2 World Geography NOTES
These are huge land masses above the water on earth.
They fit together like a huge jigsaw puzzle.
The earth is about 24,9000 miles in circumference.
4 layers make up this portion of the earth.
The Core---- This is the center of the earth and made up of solid iron or nickel
*Inner Core - This portion of the core is solid
*Outer Core - This portion is liquid
Mantle----- This part has several layers. It contains most of the earth’s mass.
The magma in the mantel is molten rock.
Crust-----
The thin layer of rock at the earth’s surface. It is 19 – 37 miles thick.
Surrounding the earth is a thin layer of gas called the ATMOSPHERE.
The Atmosphere contains the oxygen that we breath,
protects us from radiation , and space debris.
The solid rock portion of the earth’s surface is known as the LITHOSPHERE.
This includes the upper mantle and the crust portion of the earth.
Both the continents and the sea floor are part of the lithosphere.
The HYDROSPHERE is made up of all the water elements on the earth.
It includes the oceans, seas, rivers, lakes, and water in the atmosphere.
Together the atmosphere, the lithosphere, and the hydrosphere form the BIOSPHERE.
This is the pert of the earth where the plants and animals live.
This theory maintains that the earth was once a super-continent that
divided and slowly drifted apart over millions of years.
The super-continent was known as PANGEA.
This is the continuous circulation of water between the atmosphere, the earth, and the
oceans. Water evaporates into the air. It heats up and falls as rain. It then flows into
the rivers, lakes, and oceans to be evaporated again.
The earth is made up of many enormous moving pieces of the
earths lithosphere. These arte known as Tectonic Plates.
The mantle ( molten rock) under the earths crust is slowly
moving. This causes the lithosphere to crack. Thus, the
plates are slowly moving.
Tectonic plates move in one of four ways:
-spreading, or moving apart
-subduction, or diving under one another
-collision, or crashing into one another
-sliding past one another in a shearing motion
When tectonic plates come into contact, changes in the earth’s surface occur.
Three types of boundaries mark plate movement.
--Plates move apart, spreading horizontally
--Plates collide, causing either one plate to dive under the other
or the edges of both plates crumple
--Plates slide past one another
Rock will sometimes crack if it is not flexible when one plate is sliding past another. This
causes a FAULT.
As plates grind or slip past one another at a fault, the earth shakes or trembles.
This sometimes violent movement of the earth is called an EARTHQUAKE.
The location on the earth where the earthquake begins is called the focus.
The point directly above the focus is called the EPICENTER.
A special device called a SEISMOGRAPH can detect the earthquakes.
It measures the size of the waves created by the quake.
The RICHTER SCALE uses information collected by the seismograph to determine \the
strength of the earthquake. It places a number with the quake.
Most people would not notice a quake that measures a 2 on the scale.
But a quake that measures a 7 would be on the news and have major destruction.
Weathering -
The physical or chemical processes that change the characteristics of
rock on or near the surface of the earth.
Sediment – This is identifiable as mud, sand, silt, which are fine particles of rock.
-
This happens when rock is changed into something else as a result of
interaction between elements in the air or water and minerals in the rock.
Erosion - This occurs when weathering material is moved by the action of wind, water, ice, or
gravity. Material moved from one location to another results in the lowering of some locations
and increasing elevations of others.