Vocabulary
What is the thinnest layer of the earth?
The crust
Volcanoes and earthquakes are related to these.
Plate Boudary.
Plates float on top of this.
Asthenosphere.
Pangea existed many of millions of years ago.
250 million years ago.
How much of the world's volcanoes are found along the Ring of Fire?
75%
The hottest layer of the earth, and it's solid metal.
The inner core.
The mid-ocean ridge is an example of a _________ boundary and ____________ occurs here where the ocean floor forms
divergent boundary, sea floor spreading.
The thickest layer of the earth.
The mantle
Who came up with the Pangea theory
Alfred Wegener.
What type of volcano is Augustine Volcano?
Stratovolcano.
A number of rigid, but moving pieces of the earth.
Tectonic plates
Convection cycles in the mantle.
There are _____ main layers of the earth.
Four.
Continental drift theory was not accepted because.
It did not explain how the continets moved.
Why is blocky lava an important clue to the explosiveness of a volcano?
The thicker the lava, the more violent a volcano is.
Shows that the younger layer of rocks on the ocean floor are moving outwards.
Sea floor spreading.
Name three of the major plates
African plate, Antarctic plate, Eurasian plate, Indo-Australian plate, North American plate, Pacific and South American plate
The earths crust is thinnest under _______ and thickest under ________.
Ocean, and continets.
The evidence of matching fossils on two different continents ________ and ___________.
Africa and south Africa.
What happens when the gas in magma is unable to escape?
Giant explosions occur from build-up of all the gas
the sideways and downward movement of the edge of a plate of the earth's crust into the mantle beneath another plate.
Subduction
Name the two types of convergent boundaries.
Subduction, and collision.
The rigid part of the earth.
The lithosphere.
Evidence of tropical plants found on this continent.
Antartica
How many of the worlds volcanoes that have erupted are from the ring of fire?
90%