Formation Of Earth
What is a hot spot?
Why didnt people accept Wagener's theory of continental drift?
It sounded insane and he had no evidence
What are the functional layers of Earth?
lithosphere, asthenosphere, and outer core
What layer causes Earth's magnetic field?
Outer core
How do geologists think Earth was formed?
Dust particles were attracted by static electricity, causing bigger dust clumps to become rocks and the rocks were pulled together by gravity. It all merged to one and soon the earth melted and created layers.
What evidence did Wagener use to come up with his ideas of continental drift?
Glacieral scratches, Fossils, Shape of the Continents, mountain ranges, rock layers
What is sea-floor spreading?
The formation of new areas of oceanic crust through the upwelling of magma through mid ocean ridges and its subsequent outward movement on either side
What are the compositional layers of the Earth?
Inner Core, Outer Core, Mantle, Crust (Lithosphere, Asthenosphere)
Describe the role of reflection and refraction of Earthquake waves in discovering Earth's layers
The reflection and refraction of seismic waves tell scientists the composition and structure of earth?
How do geologists think the moon was formed?
A smaller planet crashed into earth, causing rocks and dust to go into space and be pulled together to cause the forming of the moon
What forms in a convergent, subduction zone between a oceanic and land plate
Trenches, Volcanic islands, volcanos in the water
Why is the pattern of magnetism on the ocean floor symmetrical on both sides of a mid ocean ridge
Because when the new ocean floor forms it creates symmetrical bands as the magnetic field flips
How do we know where the different layers begin and end?
What is the shadow zone?
A zone that doesnt recieve any seismic waves
What is the prevailing thought of where water on earth came from
meteorites
What forms in a divergent, happening on land
Rift valley and shield volcanos
Why do the iron crystals on the ocean floor point in different directions at different ages?
The align with the magnetic field of when they were formed and cooled
How did geologists think the layers of the earth came to be
As the earth cooled, the denser material sunk to the center and the lighter rose to the surface
Mountains (not volcanic)
Why doesnt the earth's lithosphere keep getting larger since magma keeps rising up at spreading centers?
The crust subducts back into the mantle
Mid ocean ridge (Volcanic mountain chain)
How do you know which way a plate is moving over a hotspot?
You draw a line from the youngest to the oldest volcano in the chain.
As Earth cooled, an atmosphere formed mainly from gases spewed from volcanoes