IGCSE Environmental Management Chapter 1 Notes

Environmental Management

Continental drift •

Continental drift is

the movement of the

Earth's continents. •  This is due to the mantles’ mantles’ movements which causes the tectonic plates to move

• Plate tectonics is the scientic theor that attempts to e!plain the movements of the Earth's lithosphere that have formed the landscape features we see across the glo"e toda. • # denition the word $plate$ in    C geologic terms means a large sla" of    1    0 solid roc%. $Tectonics$ is a part of the &ree% &ree % root for $to "uild$ and together    . the terms dene how the Earth's surface    T is "uilt up of moving plates.    C    E • o "asicall the earth's lithosphere is made up of man individual plates ()    T ma*or plates and other minor ones+ of    '    T solid roc% that ,oats upon the hot    E    /    Tmantle.    .    • Churning currents in the molten roc%s    #    2 "elow propel them along li%e a *um"le of       Pconveor "elts.

3ow tectonic plates move

Plate #oundries Convergent #oundries 4ivergent 4ivergent "oundries  Tr  Transform5fault ansform5fault "oundries "oundries

Convergent Convergent #oundries • The plates "asicall m6ove towards towards each other and destruct land 7 #asic movement of plates (in convergent "oundrie s+ 7 ceanic5continental convergence 7 ceanic5oceanic convergence 7 Continental5continental convergence

1magine these are two plates

cean c5con nen a convergence 8hen an oceanic plate pushes into and su"ducts9 under a continental plate6 the overriding continental plate is lifted up and a mountain range is created.

ceanic5oceanic convergence

8hen two oceanic plates converge one is usuall su"ducted under the other and in the process a deep oceanic trench is formed.

:or e!ample 5 Marianas Trench is a deep trench created as the result of the Phillipine Plate

Continental5continental convergence 8hen two continents meet head5on6 neither is su"ducted "ecause the continental roc%s are relativel light and6 li%e two colliding ice"ergs6 resist downward motion. 1nstead6 the crust tends to "uc%le and "e pushed upward or sidewas.  The collision of 1ndia into -sia ;< million ears ago caused the Eurasian Plate to crumple up and override the 1ndian Plate. -fter -f ter the collision6 the slow continuous convergence of the two plates over millions of ears pushed up the 3imalaas and the  Ti"etan  Ti" etan Plateau to their present heights.

4ivergentt #oundries 4ivergen • #asic movement of divergent "oundries • 4etailed information

4ivergentt #oundries 4ivergen •

-t divergent "oundaries new crust is created as two or more plates pull awa from each other. • ceans are "orn and grow wider where plates diverge or pull apart. • when a diverging "oundar occurs on land a 'rift'6 or separation will arise and over time that mass of land will "rea% apart into distinct land masses and the surrounding water will ll the space "etween them

 Transform  T ransform5fault 5fault "oundries • #asic movement • 4etailed inform information ation • E!tra inform information ation

 Transform  T ransform5fault 5fault "oundries  Transfor  T ransform5: m5:ault ault #oundaries are where two two plates are sliding hori=ontall past one another. These are also %nown as transform "oundaries or more commonl as faults. Most transform faults are found on the ocean ,oor. The commonl o>set active spreading ridges6 producing =ig5=ag plate margins6 and are generall dened " shallow earth?ua%es. - few6 however6 occur on land.

E!tra 1nformatio 1nformation n  The an -ndreas fault =one in California is a transform fault that connects the East Pacic @ise6 a divergent "oundar to the south6 with the outh &orda 55 Auan de :uca 55 E!plorer @idge6 another divergent "oundar to the north. The an -ndreas is one of the few transform faults e!posed on land. The an -ndreas fault =one6 which is a"out B6