Unit 4- Earth's Layers

Question 0

the outer most later is called

Answer 0

Crust

Question 1

how many compositional (chemical) layers does Earth have?

Answer 1

3

Question 2

Name 2 types of crust

Answer 2

Oceanic

Continental

Question 3

Oceanic and Continental crust is mostly made from what?

Answer 3

Oxygen, Silicon, and Aluminum

Question 4

the middle layer is called what

Answer 4

Mantle

Question 5

The innermost layer of the earth is what?

Answer 5

core

Question 6

The innermost layer is mostly made of what?

Answer 6

Iron and Nickel

Question 7

The innermost layer makes up about how much of Earth’s mass?

Answer 7

1/3

Question 8

how many physical layers of the earth have?

Answer 8

5

Question 9

what properties do scientists use to develop these layers?

Answer 9

whether it’s a solid or liquid

how the layer move forward transmits waves

Question 10

describe the properties of the lithosphere

Answer 10

• The outermost rigid layer
• made up of two parts the crust and the ridge
• The lithosphere is divided into pieces call tectonic plates

Question 11

describe the properties of the asthenosphere

Answer 11

• A weak or soft mantle that is made of rock that flows slowly
• tectonic plates move on top of this layer

Question 12

describe the properties of Mesosphere

Answer 12

• The strong lower part of the mantle

- Rock flows more slowly than rock in the asthenosphere does

Question 13

describe the properties of the outer core

Answer 13

• The liquid layer of Earth’s core

- it lies beneath the mantle and surrounds the inner core

Question 14

describe the properties of the inner core

Answer 14

A solid dense center of our planet

Question 15

Who first proposed the hypothesis of continental drift and when?

Answer 15

Alfred Wegener

late 1800

Question 16

what is continental drift

Answer 16

• A hypothesis proposed by Alfred Wegener

- he proposed that the continents once formed a single landmass, broke up, and drifted

Question 17

explain Wegener’s evidence to support his hypothesis

Answer 17

• fossils of the same species found on continents on different sides of the Atlantic Ocean
• locations of the mountain ranges
• Rock formations
• evidence of the same ancient climatic conditions on several continents

Question 18

what is Pangaea

Answer 18

scientists think that about 245 million years ago the continents were joined in a single large landmass (called Pangaea)

Question 19

explain what happened 245 million years ago

Answer 19

• continents were joined in a single large landmass called Pangaea
• as the continents collided to form Pangaea, mountains formed

Question 20

explain what happened 200 million years ago

Answer 20

A large wrist forms and Pangaea begin to break into two continents Laurasia and Gondwana

• The rift eventually formed the north Atlantic Ocean
• The continents broke into other continents

Question 21

explain what happened at 150 million years ago

Answer 21

A rift between Africa and South America open to form the South Atlantic Ocean

Question 22

explain what happened and 50 million years ago

Answer 22

India collided with Eurasia and the Himalaya Mountains began to form

Question 23

why was Wegener’s idea of continental drift pushed aside?

Answer 23

-scientists could not determine how continents moved

-

Question 24

what happened in the 1950s for scientist to look at Wegener's hypothesis again

Answer 24

scientists found huge underwater mountain ranges called mid-ocean ridges

Question 25

what were the three pieces of evidence to support Wegener's hypothesis?

Answer 25

- age and magnetic properties of the seafloor - seafloor spreading - Ocean trenches

Question 26

explain age and magnetic properties of the seafloor

Answer 26

mid ocean ridges form along cracks in the crust Rock samples from the sea floor revealed that the youngest rock is closest to the ridge, while the oldest rock is furthest away

Question 27

describe the seafloor spreading

Answer 27

it explains the age and magnetic patterns of seafloor rocks, scientists propose a process called seafloor spreading -in this process, molten rock from inside Earth rises through the cracks in the ridges, cools, and forms new oceanic crust

Question 28

explain ocean trenches

Answer 28

- Earth is not getting larger although the seafloor has been spreading, because they found huge trenches, like deep canyons, in the seafloor - at these sites oceanic crust is sinking to the asthenosphere - older crust is being destroyed at the same rate new crust is forming. Thus, earth remains the same size.

Question 29

describe plate tectonics

Answer 29

- A large scale movements of earth's lithosphere which is made up of the crust and the ridge, upper part of the mantle - Plate tectonics explains how and why features in the Earth's crust form and continents move

Question 30

describe tectonic plates

Answer 30

The lithosphere is divided into pieces called tectonic plates

Question 31

which is more dense continental or oceanic plates?

Answer 31

oceanic

Question 32

how many plate boundaries are there?

Answer 32

3

Question 33

describe a convergent plate boundary

Answer 33

- A convergent boundary forms when two plates collide | - when two tectonic plates of oceanic lithosphere collide, one of the plate subducts, or sinks, under the other plate,

Question 34

what is an example of a convergent boundary

Answer 34

continent to continent collision Continental ocean collision Ocean the ocean collision

Question 35

describe a divergent plate boundary

Answer 35

- it is when two plates move away from each other | - most divergent boundaries are located on the ocean floor

Question 36

described a transform boundary

Answer 36

- boundary at which two plates move past each other horizontally - they scrape against each other in a series of sudden slippages of crustal rock that are felt as earthquakes - they generally do not produce magma, unlike other types of boundaries

Question 37

what causes tectonic plates to move?

Answer 37

mental convection ridge push slab pull

Question 38

describe Mantle convection

Answer 38

- some parts of the mantle become hotter than other parts. The hot parts rise as the sinking of cooler, denser material pushes the heated material up. - this kind of movement of material due to differences in density

Question 39

describe ridge push

Answer 39

- newly formed the rock at mid ocean ridge is warm and less dense than older, adjacent rock. - this force, called ridge push, pushes the rest of the plate away from the mid ocean ridge

Question 40

describe slab pull

Answer 40

- At subduction zones, a denser tectonic plate sinks, or subducts, beneath another, less dense plate. - as it sinks, the leading edge of the plate pulls the rest of the plate with it. - this evidence leads many scientist to think that slab pull may be the most important mechanism driving tectonic plate motion

Question 41

describes the mantle

Answer 41

- located between the core and the crust | - it is a region of hot, slow flowing, solid rock

Question 42

convection

Answer 42

the movement of matter that results from differences in density caused by many variations in temperature

Question 43

how does convection work in this layer?

Answer 43

cooler rock sinks and warmer rock rises