Alfred Wegener Alfred Wegener 1880 1880 1930 1930 Continental Drift Continental Drift Becky Dobosy May 2005 Becky Dobosy May 2005
Alfred Wegener • Born in Berlin, Germany, Nov. 1, 1880. • Meteorologist and geophysicist.
Alfred Wegener • Discovered continental drift • Originated theory of Pangaea • Died Nov. 1, 1930
Alfred’s Theory Wegener believed the earth was made up of moving plates. Originally, all the continents were combined into one called Pangaea.
Early Pangaea The animals and plants could disperse with all the future continents together. The one ocean was the Panthalasia.
Later Pangaea Pangaea broke into Lausasia and Gondwanaland and trapped animals on one or the other.
Today This is the current map of our world after about 200 million years of continental drift.
The Future? Some scientists’ view of the continents in a million years.
Acceptance of the Theory Wegener’s theory wasn’t accepted until the discovery of sea floor spreading.
The spreading is caused by liquid mantle coming up and cooling to form new ground. This creates and ocean trenches and ridges, like the Mid-Atlantic Ridge.
It also causes the Atlantic Ocean to expand and the Pacific to shrink.
Fossil Proof The same fossils can be found on different continents spread miles apart.
When the continents are in Pangaea’s shape,the fossil areas match up.
Lithocology Proof Lithocology is the study of the distribution of major geological bodies such as mountains and seas.
Mountains ranges and rock bases match with the other Pangaea continents where they broke off.
Palemagnetism Proof North Pole Earth Magnetic attraction Particles in cooling rocks point to thenorth pole due to the Earth’s magnetism.
Palemagnetism cont. After drifting, the rock’s magnetic particles no longer point North.
Palemagnetism cont. From the direction the particles are pointing, we can tell where the rock originally was in Pangaea.
Tectonic Plates There are 30 plates that make up our Earth.
Divergent Boundaries • Usually on ocean floor • Creates sea floor spreading • Make ocean ridges and earthquakes
Divergent Examples Great Rift Valley - land fault Mid-Atlantic Ridge - ocean fault
Convergent Boundaries • Edge of plate sinks under neighbor • Called subduction • Makes biggest earthquakes
Examples Himalayas - land plates combining and growing California Coast - land plate growing Chile Coast - shrinking from subduction
Transforming Boundaries • Plates slide horizontally • Rough edges rub together • Cause frequent earthquakes
Transforming Fault Examples Bam Fault in Iran San Andreas Fault in Cailifornia
Earth Quakes Earth quakes (red) occur on the fault lines (yellow) of certain plates.
Folded Mountains • Wavy layers where plates collide • Rock piles up • Examples: Himalayas, Alps, Rockys, Andes
Fault Block Mountains • Plates pull apart • One side of fault goes up, the other down • Example: Sierra Nevadas Grand Tetons
Volcanic Mountains • On edges on hot spots of plates Mt Etna After Before • Examples: • Hawaii - volcanic islands • Yellowstone - underground volcano
Me Hey, my name is Becky. I live with my parents and have two older sisters. I also have a guinea pig named Chloe. I love the mountains and being outside.
Bibliography “Alfred Wegener.” Scientists: The Lives and Works. 1996 ed. George, Linda. Plate Tectonics. San Diego: Kid Haven Press, 2003. “Plate Tectonics.” World Book. 2003 ed. A Lesson in Plate Tectonics. 2005. Extreme Science. 2 May, 2005. <http://extremesc ience.com/PlateTectonicsmap.htm>