Hazardous earth

Question 1

basic structure the earth

Answer 1

Lithosphere-solid (30-40km)
Asthenosphere-semi-solid material (2900km)
Lower mantle- solid
Outer core- Liquid
Inner core- Solid

Question 2

Convection currents

Answer 2

1. Heat from core causes magma in the mantle to heat up
2. Becomes less dense and rise to the surface
3. As magma rise = cools = looses heat to surrounding rock
4. Once magma cools becomes denser than surrounding
5. Sinks back down to earths core
6. The cycle continuous

Question 3

How do convection currents effect plate tectonics?

Answer 3

Movement of magma exerts pressure on earths crust = tectonic plates move

Question 4

how is paleomagnitism evidence for sea floor spreading ?

Answer 4

-iron minerals in the lava are magnetic, they solidify in a direction depending on the magnetic field which changes direction every 100 thousand years

Question 5

how is age of sea-floor evidence for sea floor spreading

Answer 5

-the rock gets older further way from the mid ocean ridge. suggest that rock is being recycled.

Question 6

how does jigsaw fit evidence continental drift

Answer 6

-continental coastlines either side of Atlantic coastline seem like they would fit

Question 7

how does Ancient glaciation evidence continental drift

Answer 7

-glacial deposits on either side of coastlines suggest that ice sheet sheet over South Africa and Australia

Question 8

how does geological fit evidence continental drift

Answer 8

similar mountain chains and rock patterns found over seas e.g appalachains have same rock type as Britain

Question 9

how does fossil records evidence continental drift

Answer 9

-fossils of different animals found overseas. eg. mesosaurus found in Africa and South America

Question 10

how many main plates

Answer 10

7

Question 11

what is divergent (constructive) what is

Answer 11

-plates move may from each others
-mantle rock moves up and starts to melt

Question 12

what is convergent (collision or destructive) plate boundary

Answer 12

it is when plate boundaries move towards each other.
-Collision is when neither is subducted
-destructive is when the denser oceanic plate boundary is subducted

Question 13

conservative (transform)

Question 14

processes at divergent boundary

Answer 14

-mid ocean ridge- seafloor spreads and space is filled with lava to form a ridge (volcano can form and rise above sea level)
-Rift Valley- continental plates spread and because they are brittle crust fractures and areas of the crust drop down creating a ridge