Layers of the Earth & Continential Drift

Question 1

What are the three main layers of the Earth?

Answer 1

The crust, the mantle, and the core

These layers vary in composition, temperature, and physical state.

Question 2

What is the difference between continental and oceanic crust

Answer 2

Continental crust is older and less dense. Whereas oceanic crust is new crust that is constantly formed, it is found on ocean floor, thin layer.

Question 3

Lithosphere?

Answer 3

Located in upper mantle, consists of all the crust and top most part of mantle. Tectonic plates are located on the lithosphere.

Question 4

Asthenosphere?

Answer 4

Warmer region, semi - molten. Allows tectonic plates to move above it through convection currents.

Question 5

What is continental drift?

Answer 5

Alfred Wegner hypothesised thatPangaea gradually drifted apart 200 million years ago and the continents have been moving away ever since.

Question 6

Evidence 1 - Continental Drift

Answer 6

Geographical fit. Wegener noticed that the coastlines of Africa and South America appeared to fit together suggesting they were once joined together. Fit together like a puzzle piece.

Question 7

Evidence 2 - Continental Drift

Answer 7

Fossil Evidence. Presence of identical fossils found on continents that are now widely separated suggested that the continents were once joined

Question 8

Evidence 3 - Continental Drift

Answer 8

Geological evidence (rocks). Wegener found that rocks of the same age and type were found on both sides of the Atlantic Ocean, suggesting that these rocks then drifted apart on separate continents.

Question 9

Who made the continental drift theory?

Answer 9

Alfred Wegner