Chap 4 Flashcards
(43 cards)
How many plates is the earths crust made of?
How much does it move a year?
A dozen
4 in
What is a caldera and how is it formed?
It is a big bowl shaped crater. When the lava builds with ash it forms a big magma chamber
How were the Hawaiian islands created?
By a hot spot, because the oceanic plates slides under the continental one
What is mount Vesuvius most famous for?
Erupting 50 times in the last 2,000 years
Why did 1/5th of iceland’s people die after 1783?
The eruption of mount skaptar
How many people died after the mount Edna explosion?
20,000
What is the core made of?
Iron and radio activity
What is a primary force?
Internal forces of the earth - you can see it happen
What is a secondary force?
It is formed by external forces like water ice and wind- you can’t see it happening
Lava?
Outside
Magma?
Inside
What is the crust broken into?
It is broken into plates that are constantly moving
Hat is the ring of fire?
The most active region in the world with volcanoes, tsunamis, and earthquakes
What was it called when all the continents formed a super continent?
Pangea - we don’t have evidence to show that it’s true though
How do the plates move?
By the mantle and the inside of the earth
How were the Himalayas formed
Plates collided to make mountains and the Himalayas are still moving right now - one plate goes over another
What are plates called when they are moving?
Divergent
What happens when plates slid against each other
An earthquake occurs
What is a great example of plate boundaries
San Andreas fault
How was Illinois formed
Glaciers went over it and scraped it flat
Erosion?
Breaking up rocks (earths surface)
Deposition?
The eroded pieces are deposited somewhere else
Water?
The most powerful force of erosion
How many percent of this planet is water
70
