The Dynamic Earth Flashcards
What did early geologists believe before the theory of continental drift?
That the earth was cooling from the outside in and the earths crust was like the skin on custard. The skin had wrinkles and these were the continents. In the 1800s there was evidence that the continents were moving, this was explained by the earth was still cooling and the skin was contracting.
Who proposed the theory of continental drift?
A German meteorologist named Alfred Wegener.
Identify some early evidence of continental drift.
Some evidence of continental drift includes; some coastlines are practically identical and some fossils found on different continents are the same. This indicates that these continents were once one continent and are now floating away from one another.
What does the inside of the earth look like?
What is the lithosphere and the asthenosphere?
The lithosphere is a part of the earth that consists of the upper part of the upper mantle and the earths crust. The asthenosphere is the part below the lithosphere where the tectonic plates lie.
Describe the theory of plate tectonics.
Plate tectonic theory suggests that the Earth’s lithosphere is not a uniform unbroken covering, but is divided into a number of ‘plates’
Explain the process in which tectonic plates move.
Tectonic plates move via convection cells which occur when hot magma comes up from the earths core and collides with the less hot area around the asthenosphere and pushes the tectonic plates along.
How do convection currents happen in boiling water?
What are the three types of plate boundries and how do they happen?
The three types of plate boundries are; Divergent, Convergent and Transform boundries.
