IGNOU MSCCFT and PGDCFT Exam Question Pattern: MCFT003 Counselling and Family...
The Changing Earth - 01 The Structure of the Earth.
1. Ian Anderson (2013)
Saint Ignatius College Geelong
01. Structure of the Earth.
Source:
http://earthobservatory.nasa.gov/Features/BlueMarble/
BlueMarble_history.php
2. Structure of the Earth.
Earth is made up of four layers.
Inner core.
Outer core.
Mantle.
Crust.
Source:
http://www.bbc.co.uk/schools/gcsebitesize/geography/
natural_hazards/tectonic_plates_rev1.shtml
3. Structure of the Earth.
Inner core.
Solid.
~1200 km thick.
High in iron & nickel.
Temperatures up to 7000°C.
The hottest part of the
earth.
Heat is generated by:
Left over heat from earth’s
creation.
Radioactive decay of elements
including uranium, thorium &
potassium.
Source:
http://www.bbc.co.uk/schools/gcsebitesize/geography/
natural_hazards/tectonic_plates_rev1.shtml
4. Structure of the Earth.
Outer core.
Surrounds the inner core.
Temperatures up to 6000°C.
Molten.
High in iron & nickel.
~2000 km thick.
Source:
http://www.bbc.co.uk/schools/gcsebitesize/geography/
natural_hazards/tectonic_plates_rev1.shtml
5. Structure of the Earth.
Mantle.
Made up of molten rock
called magma.
Section closest to the core is
more molten than the section
closest to the earth’s crust.
Temperatures ranges from
500 near the crust to 3000°C
closer to the core.
Widest section of earth.
~2900 km thick.
Source:
http://www.bbc.co.uk/schools/gcsebitesize/geography/
natural_hazards/tectonic_plates_rev1.shtml
6. Structure of the Earth.
Crust.
The outer layer.
Solid rock.
Includes all landforms, rocks
& soil.
Varies in thickness.
~8 km thick below the oceans
to ~40 km below the continents.
Broken up into tectonic
plates. Source:
http://www.bbc.co.uk/schools/gcsebitesize/geography/
natural_hazards/tectonic_plates_rev1.shtml
7. Plate tectonics.
The earth’s crust is broken up into pieces called
tectonic plates.
Source: http://www.moorlandschool.co.uk/earth/tectonic.htm
8. Plate tectonics.
The earth’s crust is broken up into pieces called
tectonic plates.
The plates are floating on the molten rock of the
mantle.
Greatest geological activity (volcanoes, earthquakes &
mountain building) occurs on the edges of these plates.
e.g. Ring of fire along the edges of the Pacific Plate.
Source: http://www.moorlandschool.co.uk/earth/tectonic.htm
9. Plate tectonics.
Convection currents within
mantle move tectonic plates
(~1 cm per year).
Driving some plates apart
(e.g. North American &
European plates) and causing
others to collide (e.g. Pacific
Plate & South America).
Results in geological activity
and oceanic trench
formation.
Source:
http://facstaff.gpc.edu/~pgore/Earth&Space/GPS/
platetect.html
10. Plate tectonics.
Great Rift Valley, Africa.
Source:
http://www.imagesoftheworld.com/volcanoes/
74africa.html
Source: http://ethiopiaembassy.eu/country-profiles/tourism/
Source: http://www.amazon.com/Africas-Great-Valley-Nigel-
Pavitt/dp/0810906023
11. Plate tectonics.
Evidence for theory of plate tectonics includes:
Shape of the continents.
Source:
http://facstaff.gpc.edu/~pgore/Earth&Space/GPS/
platetect.html
12. Plate tectonics.
Evidence for theory of plate tectonics includes:
Shape of the continents.
Fossil evidence.
Source: http://courses.bio.indiana.edu/L104-Bonner/Sp10/Part3.html
13. Plate tectonics.
Evidence for theory of plate tectonics includes:
Shape of the continents.
Fossil evidence.
Geological similarities
between continents.
Source: http://courses.bio.indiana.edu/L104-Bonner/Sp10/Part3.html
14. Plate tectonics.
Evidence for theory of plate tectonics includes:
Shape of the continents.
Fossil evidence.
Geological similarities
between continents.
Younger age of sea floor
compared to continental
crust.
Source: http://courses.bio.indiana.edu/L104-Bonner/Sp10/Part3.html
Plate tectonics: The continental and oceanic plates are moved by convection currents within the Earth's mantle, driving some plates apart (eg. the North American and European plates) and causing others to collide (e.g. Pacific Plate and South America). Theory proposed (but inspired by Wegner) by Arthur Holmes in 1929 and provided a mechanism for plate movement of the Earth's crust. This theory is still accepted today - although still being refined.
he red line on this map shows the eastern and western faults of the Great Rift Valley, which travels 4,500 miles from southern Africa, under the Red Sea, and into Syria in southwestern Asia.
Shape of the coastlines - Africa and South America would fit together like jigsaw puzzle pieces.Fossil evidenceGlossopteris flora - a type of Late Paleozoic seed ferns (plant fossils) that were found in Gondwanaland (India, Africa, Australia, S. America, Antarctica) Mesosaurus, a freshwater aquatic reptile whose fossils were found in South America and AfricaGeologic similarities between S. America and AfricaSame stratigraphic sequence (i.e. same sequence of types of layered sedimentary rocks)Mountain belts and folded rocks would line up if you could push the continents back togetherYouth of ocean basins and sea floor.Before the seafloor rocks were sampled and dated, the hypothesis is that they would be very old and would be covered by thick accumulations of sediment. The deep sea drilling efforts have revealed that the basaltic rocks of the seafloor are actually quite young. Seafloor basalt dates to less than 200 million years (most is younger than 150 million years). The seafloor is much younger than we expected. This is because new seafloor is continually forming at the mid-ocean ridges and spreading outward away from the ridge in conveyor belt fashion. The Earth is not expanding. Older seafloor rocks have been subducted, or carried down into the Earth's mantle in deep sea trenches and melted.
Shape of the coastlines - Africa and South America would fit together like jigsaw puzzle pieces.Fossil evidenceGlossopteris flora - a type of Late Paleozoic seed ferns (plant fossils) that were found in Gondwanaland (India, Africa, Australia, S. America, Antarctica) Mesosaurus, a freshwater aquatic reptile whose fossils were found in South America and AfricaGeologic similarities between S. America and AfricaSame stratigraphic sequence (i.e. same sequence of types of layered sedimentary rocks)Mountain belts and folded rocks would line up if you could push the continents back togetherYouth of ocean basins and sea floor.Before the seafloor rocks were sampled and dated, the hypothesis is that they would be very old and would be covered by thick accumulations of sediment. The deep sea drilling efforts have revealed that the basaltic rocks of the seafloor are actually quite young. Seafloor basalt dates to less than 200 million years (most is younger than 150 million years). The seafloor is much younger than we expected. This is because new seafloor is continually forming at the mid-ocean ridges and spreading outward away from the ridge in conveyor belt fashion. The Earth is not expanding. Older seafloor rocks have been subducted, or carried down into the Earth's mantle in deep sea trenches and melted.
Shape of the coastlines - Africa and South America would fit together like jigsaw puzzle pieces.Fossil evidenceGlossopteris flora - a type of Late Paleozoic seed ferns (plant fossils) that were found in Gondwanaland (India, Africa, Australia, S. America, Antarctica) Mesosaurus, a freshwater aquatic reptile whose fossils were found in South America and AfricaGeologic similarities between S. America and AfricaSame stratigraphic sequence (i.e. same sequence of types of layered sedimentary rocks)Mountain belts and folded rocks would line up if you could push the continents back togetherYouth of ocean basins and sea floor.Before the seafloor rocks were sampled and dated, the hypothesis is that they would be very old and would be covered by thick accumulations of sediment. The deep sea drilling efforts have revealed that the basaltic rocks of the seafloor are actually quite young. Seafloor basalt dates to less than 200 million years (most is younger than 150 million years). The seafloor is much younger than we expected. This is because new seafloor is continually forming at the mid-ocean ridges and spreading outward away from the ridge in conveyor belt fashion. The Earth is not expanding. Older seafloor rocks have been subducted, or carried down into the Earth's mantle in deep sea trenches and melted.
Shape of the coastlines - Africa and South America would fit together like jigsaw puzzle pieces.Fossil evidenceGlossopteris flora - a type of Late Paleozoic seed ferns (plant fossils) that were found in Gondwanaland (India, Africa, Australia, S. America, Antarctica) Mesosaurus, a freshwater aquatic reptile whose fossils were found in South America and AfricaGeologic similarities between S. America and AfricaSame stratigraphic sequence (i.e. same sequence of types of layered sedimentary rocks)Mountain belts and folded rocks would line up if you could push the continents back togetherYouth of ocean basins and sea floor.Before the seafloor rocks were sampled and dated, the hypothesis is that they would be very old and would be covered by thick accumulations of sediment. The deep sea drilling efforts have revealed that the basaltic rocks of the seafloor are actually quite young. Seafloor basalt dates to less than 200 million years (most is younger than 150 million years). The seafloor is much younger than we expected. This is because new seafloor is continually forming at the mid-ocean ridges and spreading outward away from the ridge in conveyor belt fashion. The Earth is not expanding. Older seafloor rocks have been subducted, or carried down into the Earth's mantle in deep sea trenches and melted.