2. Alfred Wegener (1903) suggested
and presented evidence that the
continents were once a single
supercontinent, called Pangea,
which divided ~ 200 Million
years ago into Laurasia and
Gondwanaland and later into
the continents we see today
(“continental drift”)
3. Fossils of the land-bound lizard Lystrosaurus were found in Africa,
Antarctica and India, suggesting that these continents were one
landmass during the life-time of this critter
4. Geologic evidence for “continental drift”
Distribution of warm-water fossils
Rocks of same age cross continents
5. Topography of Earth
Huge mountain ranges (ridges, like the Mid-Atlantic Ridge) circle the globe on the
ocean floors
6. The crust of Earth consists of 11 major tectonic plates
7. Epicenters of major earthquakes tend to occur along ocean ridges
and plate boundaries
11. The Hawaiian island chain is a wonderful example of plate tectonics
in the middle of a plate. It is fed by a stationary mantle plume under
Loihi, and the Pacific Plate glides over it at a speed of ~ 5 cm/year,
carrying the islands with it in a northwesterly direction.
12. Ages of the Hawaiian islands: An example of plate tectonics
associated with a mantle plume
14. Volcanoes: Pages 53 - 62
• Volcanoes are found on the surface of Earth and Venus; Mars has
fewer volcanoes with some signs of relatively recent volcanic activity.
• The volcanoes on Jupiter's satellite Io have turned the satellite inside
out; it is heated inside by the tidal flexing action of nearby massive
Jupiter.
• Volcanoes of ice may have created some of the features now frozen
into the bright smooth surface of Neptune's largest moon, Triton;
dark geyser-like plumes have been observed in the process of
eruption on the satellite.
25. Olympus Mons on Mars, the tallest mountain in the Solar System
26. Olympus Mons on Mars, compared to the Hawaiian island chain
640 km
27. Right: Eruption of
the volcano Pele on
Jupiter’s moon Io.
Below: Top view of
volcano Pele
The volcanic plume (above) is 1,300
km wide and 600 km high.
