Geography tectonic plates

Question 1

how thick and how hot is the core?

Answer 1

Inner core: 1,400km,
Outer core: 2,100km,
Both are 3000-5000 degrees

Question 2

why is the inner core solid?

Answer 2

because of the extreme pressure pushing the atoms together

Question 3

Temperature range of mantle?

Answer 3

800-3000 degrees

Question 4

parts of the mantle and its appearance?

Answer 4

lithosphere: rigid and brittle, floating on the asthenosphere
asthenosphere: it is very close to the rocks melting point, and very high in pressure, hence the rocks can be easily deformed

Question 5

how do tectonic plates move?

Answer 5

Convection currents. The mantle material expands, rising and spreading beneath the plates, cause the plates to be dragged. The mantle cools and sinks pulling the plates along

Question 6

what is slab pull force?

Answer 6

when a subducting, sinking oceanic plate at subduction zones pull the rest of the plate behind it

Question 7

what is the main cause for plate movement?

Answer 7

Slab-pull force

Question 8

why are transform plate boundaries bad?

Answer 8

Because it causes a build up of tremendous stress, to be released suddenly to cause devastating earthquakes

Question 9

what are sedimentary rock?

Answer 9

Formed from multiple layers of sediment

Question 10

what are igneous rocks?

Answer 10

Rocks that have cooled and solidifyed

Question 11

what are metamorphic rocks?

Answer 11

When rocks are changed by high temperatures o pressure

Question 12

Give 3 reasons why people may choose to live near a volcano.

Answer 12

Fertile soil, volcanic soil is rich in minerals. (Volcanic soils of Bali in Indonesia support cultivation of crops such as tea,)
Tourism, people enjoy the scenery. (Roman town of Pompeii, Italy was buried in layers of ash, 3 million people visit it annually)
Geothermal energy. Water comes into contact with hot rocks and evaporates, which is harnessed. (70% in Iceland are heated by volcanic steam)

Question 13

What happens at transform plate boundary? Example of fault?

Answer 13

Plates slide past each other and get stuck. When pressure is released an earthquake occurs.
San Andreas fault

Question 14

What can be created from convergent continental plate boundaries? How?

Answer 14

Fold mountains - continental crust is crumpled

Question 15

Which is denser, oceanic or continental crust?

Answer 15

Oceanic

Question 16

Oceanic oceanic plate divergence

Answer 16

when the plates diverge, fractures are formed at the plate boundary, allowing the magma to rise at the zone of divergence, creating a ridge of ocean floor called mid oceanic ridge
Magma rises at the zone of divergence, builds up and solidifying to form undersea volcanoes, which in turn rises above ocean level, forming volcanic islands

Question 17

what happens in a continental continental plate divergence

Answer 17

The continental plates diverge, stretching and causing fractures to form at the plate boundary, where two scenarios can happen. Tensional forces could cause the central block of land could subside, resulting in a rift valley BETWEEN PARALLEL FAULTS. Creating a rift valley
Or the surrounding blocks of land could subside, causing a block mountain to form BETWEEN PARALLEL FAULTS.

Question 18

what is a block mountain?

Answer 18

A block of land with steep slopes left standing higher than the surrounding land

Question 19

Oceanic oceanic plate convergence

Answer 19

When they collide, the denser oceanic plate will subduct under the other plate, forming a oceanic trench (at the point of sunduction).
The subducting plate causes the plate above it to melt, allowing magma to rise through and form volcanoes
Earthquakes might occur due to friction between subducting plates

Question 20

Continental continental plate convergence

Answer 20

the continental plates are too buoyant to subduct, so they compress. The compressional forces cause rocks to buckle and fold forming mountains

Question 21

Oceanic continental plate convergence?

Answer 21

the oceanic plate subducts, causing a underwater (duh) trench to form at the point of subduction, while fold mountains are formed on the continental plate. The subducting plate causes the plate above it to melt, allowing magma to rise up and form volcanoes

Question 22

small rocks that come out of the volcano during eruption

Answer 22

pryoclast

Question 23

Low silica lava

Answer 23

not very viscous, form shield volcanoes, flows very fast

Question 24

high silica lava

Answer 24

very viscous stratovolcano, flows very slowly

Question 25

a reservoir of molten rock beneath the earth crust

Answer 25

magma chamber

Question 26

vulcanicity

Answer 26

upward movement of magma into and onto earth’s surface

Question 27

Example of shield volcano

Answer 27

Mount Washington in the united states of america

Question 28

Example of stratovolcano

Answer 28

Mount Pinatubo in Philippines, in 1991

Question 29

Pyroclastic flow

speed?

Answer 29

Pyroclasts that mix with super heated gas, so flying rocks mixed with gas,
40 metres per second