C1 - Earth Science Flashcards
Where do earthquakes happen?
At plate boundaries.
How do new islands form?
when plates move apart, magma rises from the mantle to fill the gap. Magma rises due to convections currents inside the mantle.
How do earthquakes form?
Plates rub against each other. The friction forces build up until the force becomes too big and the plates move suddenly.
What is the name of the super continent?
Pangaea
What causes continental drift?
Convection currents inside the mantle caused by radioactive processes inside the core.
Why did no one believe Alfred Wegener?
He had no evidence that continents moved.
Describe Alfred Wegener’s idea of how continents formed.
All continents once were joined together but moved apart over time.
How did other scientists explain matching fossils in Africa and South America?
Continents were joined by land bridges. Animals walked over these which were later flooded and disappeared which cut the animals off from each other.
What evidence do we have that continental drift is happening?
Volcanoes, earthquakes, tsunamis, ocean ridges, new mountains and islands form.
How did scientists before 1900 explain mountain formations?
As the Earth cooled, the crust shrank which caused it to form wrinkles.
Why is it difficult to predict earthquakes?
Scientists cannot see what is going on below the crust and cannot measure the forces that build up and say when the forces become too big.
Why are not all earthquakes reported in newspapers?
Because the effects cannot be felt or the damage done is not big enough.
