The dynamics of the geosphere- Plate tectonics

THE PLATE TECTONICS

• Look for the Alfred Wegener biography and write an abstract.
• In 1912, Alfred Wegener proposed the idea of the continental drift.
• According to his theory, in the past, there was a supercontinent which broke apart to form the present-day continents, which slowly drifted across the mantle until they reached their current positions.
• 03 Continental Drift (Einbetten)

THE PLATE TECTONICS

• The Earth’s crust is constantly moving, both vertically and horizontally, at rates of up to several centimeters a year. When the plates move, the continents and ocean floor above them move as well. Continental Drift occurs when the continents change position in relation to each other.
• While tectonic plates is a relatively new idea, scientists have been gathering data in support of the Continental Drift theory for a very long time. Wegener used the fit of the continents, the distribution of fossils, a similar sequence of rocks at numerous locations, ancient climates, and the apparent wandering of the Earth’s Polar regions to support his idea.

THE PLATE TECTONICS

• Wegener’s explanations for the forces which caused continental drift proved to be incorrect, however, his observations served as the basis for the theory of plate tectonics in 1970, which has the following postulates:
• • The lithosphere is divided into rigid fragments called lithospheric plates or tectonic plates, which are composed of oceanic lithosphere or a combination of the oceanic and continental lithosphere. (see PANGEA resource)
• • Lithosphere plates are dynamic, they move, increase or decrease in size and change shape.
• • The plate interacts, especially at their edges, where they form divergent, convergent and transform boundaries.