Continental Drift
What was the supercontinent called?
Pangea
Name the three different ways plates move (boundaries)
Divergent, convergent and transform
What are midocean ridges?
Long zipper like chains of undersea mountains
define tsunami
a wave or series of waves produced by an earthquake or landslide
what is a volcano?
a mountain that opens inward to molten rock below the Earth's surface
Define "continental drift"
hypothesis that all of the continents has once been fused together and over time they had drifted apart
Which way do plates move in transform boundaries?
slide past each other
what are ocean trenches?
undersea valleys which are the deepest part of the ocean
define an earthquake
shaking and trembling that results from plate movement where plates grind to a halt, remain stuck and built up stress causes plates to lurch into motion
what is a dormant volcano?
a volcano that poses little threat but could be reawakened
What clues supported the hypothesis of continental drift
Land features, fossils and climate
What is subduction?
the sinking movement of the ocean floor back into the mantle
explain sea floor spreading
molten rock flows up through a crack in the Earth's crust and hardens into solid strips of new rock on both sides of the crack, pushing older crust away from the ridge.
how are the waves of an earthquake measured
a seismograph device
What three types of volcanoes did we cover?
Cinder cone, composite and shield
What was the name of the book and author who posed the hypothesis of continental drift
Alfred Wegener, "The Origin of Continents"
How did the Himalayas/Mt. Everest form?
when two continents collide -> convergent boundary
what is an earthquake's magnitude?
what is the difference between lava and magma?
Magma is molten rock beneath the Earth's surface. Lava is magma that has reached the surface
What drove continental drift?
Moving ocean floor plates
What is a fault?
a break in the Earth's crust where movement happens
what is a moment magnitude scale?
measurements of energy released from an earthquake represented by a 32 fold increase
monitor gas emissions, seismographs to detect rumblings and tiltmeter device that measures volcanic swelling of magma chamber