EOY TECTONICS Paper 1

Question 1

WHAT FORMS EARTHS SURFACE

Answer 1

CRUST

Question 2

what is crust

Answer 2

a rock layer forming the upper part of the lithosphere

Question 3

what is lithosphere and describe its texture and what it includes

Answer 3

the upper layer of earth. It is cool and brittle. Includes the very top of the mantle and the crust

Question 4

What is the lithosphere split into

Answer 4

into tectonic plates

Question 5

the tectonic plates that the lithosphere is split into move at what rate and on what layer

Answer 5

move very slowly, 2-5cm per year, on a layer called the asthenosphere

Question 6

what is the asthenosphere

Answer 6

part of earth’s mantle, is hot and semi-molten and lies beneath the tectonic plates

Question 7

two types of core

Answer 7

outer core, inner core

Question 8

two types of mantle

Answer 8

asthenosphere, lower mantle

Question 9

two types of lithosphere

Answer 9

continental crust, oceanic crust

Question 10

briefly describe and name the two types of crust

Answer 10

continental curst; forms on land , mostly made of granite which is a low density igneous rock. thicker and less dense

oceanic crust; under the oceans and is much thinner, denser and made of igneous rock called basalt. thinner and more dense

Question 11

what are plate boundaries

Answer 11

where plates meet

Question 12

direction that plates move in is determined by what

Answer 12

the type of boundary

Question 13

the movement of plate creates three types of boundary; name them

Answer 13

DIVERGENT, CONVERGENT AND CONSERVATIVE

Question 14

most earthquakes and volcanoes are found on what

Answer 14

plate boundaries

Question 15

why do tectonic plates move

Answer 15

due to convection currents in the mantle

Question 16

how do we know that inside the earth is hot

Answer 16

because of
molten lava spewing from active volcanoes
hot springs and geysers

Question 17

what is heat from inside the earth called

Answer 17

geothermal

Question 18

what is geothermal

Answer 18

‘earth heat’/ heat inside the earth

Question 19

what is geothermal heat caused by

Answer 19

by the radioactive decay of elements like uranium and thorium in the core and mantle. This raises the core’s temperature to over 5000 degrees C.

Question 20

what is radioactive decay

Answer 20

atoms of unstable elements that release particles from their nuclei and give off heat

Question 21

why inner core stays solid

Answer 21

because its under huge pressure and is so deep

Question 22

why is outer core liquid

Answer 22

because it is under lower pressure

Question 23

as heat rises from the outer core, it creates 1) __________ _______ in the liquid outer core and mantle. These vast mantle 2) ______ ______ are strong enough to move the 3)______ ______ on the Earth’s surface.

Answer 23

1) convection currents
2) convection currents
3) tectonic plates

Question 24

The crust is divided into _____ called ______

Answer 24

1) slabs 2) tectonic plates

Question 25

the parts of convection cells where heat moves towards the surface are called what

Answer 25

plumes

Question 26

what are plumes

Answer 26

the parts of convection cells where heat moves towards the surface. The mantle in a plume is less dense. Plumes bring magma to the surface. If magma breaks through crust, it erupts as lava in a volcano.

Question 27

what is magma

Answer 27

molten rock

Question 28

some plumes rise like long sheets of heat. What do these form

Answer 28

divergent plate boundaries at the surface

Question 29

other plumes are like columns of heat. what do these form

Answer 29

hot spots

Question 30

where do convection currents only occur within

Answer 30

the upper mantle (asthenosphere) where it is semi-molten

Question 31

how convection currents work step by step

Answer 31

1) energy from radioactive decay in the core heats up the fluid asthenosphere
2) the hot liquid is less dense than its surroundings, so it rises upwards
3) when it reaches the top, it cools
4) it becomes more dense, and therefore sinks back down to the bottom
5) It is heated up again, and the cycle continues
6) The plates, which lie on top, are pushed and pulled by the convection currents in the asthenosphere

Question 32

what is a convection current

Answer 32

the movement of a fluid by a difference in temperature or density