Chapter 15 - Layers of the Earth + tectonics Flashcards Preview

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Flashcards in Chapter 15 - Layers of the Earth + tectonics Deck (28)
1

What percent of the Earth is the Mantle?

66%

2

What percent of the Earth is the Core?

33%

3

The outer core is (state of mass) and the inner core is (state of mass)

Outer core - liquid
Inner core - solid

4

what is the core mostly made of?

iron and nickel

5

what are the 2 types of crust?

oceanic crust and continental crust

6

What is the crust mainly composed of?

Oxygen, Silicon, and aluminum

7

Put the 5 layers of the Earth in order

Lithosphere, Asthenosphere, Mesosphere, Outer core, inner core

8

What does the lithosphere include?

all of the crust and the ridged outer layer of the mantle

9

What layer of the Earth are tectonic plates?

Lithosphere

10

What does the Mesosphere consist of?

the strong lower part of the mantle - going all the way down to the beginning of the core

11

What does the asthenosphere consist of?

a plastic layer of the mantle on which tectonic plates flow, and solid, slow moving rock.

12

How are scientists able to identify the composition and density of the mantle and core without drilling down to it?

by measuring the speed of seismic waves through each part of the Earth

13

What was the giant landmass 245 million years ago called?

pangea

14

Pangea split into 2 continents called

Laurasia and Gordwana

15

what are mid-ocean ridges?

chains of underwater mountains where molten rock from the mantle comes up into the crust and solidifies, creating new oceanic lithosphere. Site of sea-floor spreading

16

who developed the theory of the continental drift?

Wegner

17

What percent of the Earth is the Crust?

Crust

18

What formations occur at Transform boundaries?

Extreme earthquakes

19

What formations occur at convergent boundaries?

Mountains, volcanic arcs, and island arcs

20

What formations occur at Divergent boundaries?

Mid-ocean ridges

21

what are the 3 types of convergent boundaries and what do they form?

continental-continental --- Mountains
continental- oceanic ---- volcanic arcs
oceanic-oceanic --- Island arcs

22

What is a likely cause of lithospheric plate movement?

Convection currents in the asthenosphere

23

what happens during transform boundaries?

Tectonic plates slide past each other horizontally

24

what happens during convergent boundaries?

tectonic plates collide

25

what happens during Divergent boundaries?

tectonic plates move away from each other due to the molten rock rising up from mid-ocean ridges - it pushes the plates away

26

What causes the striped pattern of materials pointing to different magnetic poles?

magnetic reversals ----- some new material is formed from the asthenosphere, which points toward north during regular polarity. Then, new material is formed during reverse polarity, causing that material to point to south

27

Which type of crust is denser but thinner?

oceanic crust

28

which type of crust is lighter but thicker?

continental crust