Week 3

Question 1

Continental margin

Answer 1

?????

Question 2

2 types of continental margins

Answer 2

1. Passive

Active

Question 3

Passive

Answer 3

Passive: no break, gradual transition from continental to oceanic lithosphere. The plate can be both oceanic and continental lithosphere (there is no boundary)

Question 4

Active

Answer 4

Plate boundary break in lithosphere. (Earthquakes and volcanoes). Can happen anywhere but not on a margin

Question 5

Divergent plate boundary setting

Answer 5

Continental: rift zones
Oceanic: mid ocean ridges

Question 6

Rift zones

Answer 6

2 continental lithospheres diverging, pulls continents apart and makes seas( earthquakes and volcanoes ) the ground is dropping. Earthquakes weaken everything, it fills with magma and eventually turns to water

Question 7

Mid ocean ridges

Answer 7

2 oceanic lithospheres spreading apart, density increases as you go away from the ridge because it gets more dense with age, it is hot in the middle and cools as it goes out making it more dense

Question 8

How do we know we have a plate boundary

Answer 8

When we see a trench, and a series of volcanoes follows it u

Question 9

Magma only forms from ____

Answer 9

Subduction zones

Question 10

Convergent boundaries are also called ____

Answer 10

Subduction zones

Question 11

Subduction zones happen because

Answer 11

Lithosphere is being subducted into the mantle the density of the lithospheric plate is more dense than the asthenospehere

Question 12

What is more dense: oceanic or continental crust

Answer 12

Oceanic

Question 13

Only oceanic lithosphere _____

Answer 13

Will subduct

Question 14

How do convergent plate boundaries form volcanoes (oceanic cont)

Answer 14

Oceanic crust subducts ad creates magma that comes up and makes volcanic arcs

Question 15

How do convergent plate boundaries form volcanoes (oceanic oceanic)

Answer 15

The older crust subducts and magma comes up

Question 16

How do convergent plate boundaries form volcanoes (cont cont)

Answer 16

Can’t subduct. They crunch into each other, thickening the crust and creates mountains

Question 17

Transform plate boundary

Answer 17

Plates move away and rub against each other, new oceanic crust is formed. The grinding together creates earthquakes

Question 18

How do we know we have a plate boundary

Answer 18

Look down and there’s a trench and a series of volcanoes follows it

Question 19

Why is rate of lithosphere production equal to destruction

Answer 19

Older, denser portions descend into the mantle at a rate equal to seafloor production

Question 20

How do mountain belts form

Answer 20

Collision of 2 converging continental fragments

Question 21

Evidence to prove plate techtonoc theory

Answer 21

Drilling