10.1

Question 1

Layers of rock

Answer 1

Crust -lithosphere (rigid rock)
Upper mantle
Lower mantel -Asthenosphere (semi liquid)
Outer core -Nickel, iron (liquid)
Inner core -Iron (solid)

Question 2

Crust

Answer 2

-Outermost layer of the earth
-5-30km thickness
-Broken into larger parts called tectonic plates
-Plates move around on top of the semi liquid asthenosphere

Question 3

Alfred wegner

Answer 3

-Found out that continents fit together like a jigsaws puzzle
-Preposed that 200 million years ago all continents were joined together forming a super continent call Pangea.
-He proposed the theory of continental drift
-His evident for this was Fossils of the same species were spread across different continents e.g the Mesosaurus was found in south America and Africa

Question 4

Mary tharp

Answer 4

-Discovered that the seafloor was not flat
-found underwater ranges and underwater volcanoes over 3000m tall and 4500m long, trenches 7km deep
-These chains are called the great ocean ridge

Question 5

Harry hess

Answer 5

-Preposed the theory of seafloor spreading
-Magma from underwater volcanoes were forming new crust and pushing the old crust outward, the old sea floor would disappear into the underwater trenches
-1 age of seafloor (rockes near the edges were generally younger while the rocks near trenches were older
-2 The layer of sediments near the ridges were thinner where as the sediments near trenches were thicker
-3 Magnetic striping

Question 6

Covenction currents

Answer 6

Hot magma rises up to the asthenosphere, hitting the plates and pushing them before cooling and sinking to the asthenosphere

Question 7

gravity

Answer 7

slab pull - gravity pulls the heavier oceanic crusts near the trentches pulling the rest of the plate into the matle
ridge push - new crust forms at the ridges pushing the older crust away