Alfred Wegener

The Theory of Pangaea The theory was originated and published by a German geologist and meteorologist named Alfred Wegener in The theory was originally rejected by other scientists because he failed to provide an adequate explanation. Wegener named the said supercontinent Pangaea meaning “all lands”. It is said to have existed in the carboniferous period. It suggests that the planet was one huge mass of land that broke apart at it’s boundaries and became the continents we have today. Another theory that was being discussed at the time was the contraction theory, or the idea suggesting that the planet was once a ball of magma and in the process of cooling, the surface cracked and folded in on itself. Alfred Wegener’s prior line of work allowed him better understanding of the science he was dealing in. Some people such as Harry Hess(1962), R. Dietz(1961) and Arthur Holmes(1929) supplied ideas and facts later on that helped proved Wegener right.

Convergent Boundaries A convergent boundary is a borderline where two plates overlap. It is formed when two plates come towards each other and slide over one another. There are oceanic-continental, oceanic- oceanic and continental- continental convergences. Hazards such as mountains, volcanoes, landslides, mudslides, avalanches, high plateaus and trenches are characteristics of this strange but natural occurrence. One example of a Convergent boundary is the Washington Oregon coast line. The plates involved in this boundary are the Juan de Fuca oceanic plate and the westward moving North American continental plate.

Divergent Boundaries A divergent boundary is a common geological phenomenon created by two plates moving away from each other. This causes shield volcanoes and earthquakes. An example of a real-life divergent boundary is the Mid-Atlantic Ridge, a fault line under the Atlantic Ocean. This fault separates the Eurasian plate from the North American plate in the North Atlantic. It also separates the African Plate from the South American Plate in the South Atlantic.

Transform Boundaries A transform boundary is a hazard caused by two tectonic plates drifting past each other and creating friction. When this happens you get earthquakes, volcanic activity is rare because the typical magma sources of an upwelling convection current or a melting sub ducting plate are not present. An example of this is the San Andreas fault line. It connects a divergent boundary in the Gulf of California with the Cascadian sub ducting zone.

Real World Connections We live on the North American plate. The plates that surround the United States are the Coco plates. There are fault lines in the Mid-east, South-east, the west coast of California and South west border of Alaska. There are potential hazards based on these fault lines in the U.S.