Tectonics

Question 1

Name all the earths years

Answer 1

The Crust (the top of lithosphere)
The lithosphere
The upper mantle ( the asthenosphere)
The lower mantle
The outer core
The inner core

Question 2

Describe the inner core

Answer 2

-Solid ball of iron and nickel
-Under huge amounts of pressure
-Contains uranium and thorium(responsible for the earths internal energy)

Question 3

Describe the outer core

Answer 3

-Molten liquid layer of iron and nickel that
- surrounds the inner core
-Heat from the outer core creates convection currents

Question 4

Describe the Mantle

Answer 4

-Largest layer behaves like a dense fluid
-The upper layer( asthenosphere) constantly moves and flows due to convection currents
-mainly solid rock

Question 5

Describe the Lithosphere

Answer 5

solid rock
0-100 km thick (continental)
6-8km thick ( oceanic)

Question 6

How are convection currents formed

Answer 6

1. Energy from the radioactive decay in the core heats up the asthenosphere
2. The hot liquid is less dense than its surroundings, so it rises upwards
3. When it reaches to the top, it cools
4. It becomes more dense and cools and sinks back down
5. the cycle continues and the plates which lie on the top, are pushed and pulled by the convection currents in the athenosphere

Question 7

How does the divergent plate boundary move

Answer 7

Moves apart <~ ~>

Question 8

How does the conservative plate boundary move

Answer 8

Slides past each other ~>
<~

Question 9

How does the convergent plate boundary move

Answer 9

Moves towards each other ~><~

Question 10

What is formed at a divergent plate boundary

Answer 10

The plates are pulled apart causing magma to rise from the middle creating a Shield volcano, this process can happen on the continental or the oceanic

Question 11

What is formed at a convergent plate boundary

Answer 11

Composite volcanoes form when the continental crust meets the oceanic crust
When a continental meets a continental fold mountains form

Question 12

What are Hotspots

Answer 12

Hotspots are areas of volcanic activity that aren’t related to plate boundaries. Hot Magma from the mantle rises and burns a hole through the crust.

Question 13

Describe the Volcanoes formed on a divergent plate boundary

Answer 13

Non explosive eruptions. Runny, fast flowing Ballistic Lava. Shallow sided ( Shield volcanoes)

Question 14

Describe the Volcanoes formed on a convergent plate boundary

Answer 14

very explosive eruptions. Thick, slow moving andesitic lava. usually steep sided (composite volcanoes).

Question 15

Describe the Volcanoes formed on a conservative plate boundary

Answer 15

No volcanoes as no crust is being destroyed and no magma is generated

Question 16

Describe the size of earthquakes formed on a divergent plate boundary

Answer 16

Smaller earthquakes as there is less built up friction. (5.0-6.0 on the Richter scale)

Question 17

Describe the size earthquakes formed on a convergent plate boundary

Answer 17

Earthquakes are very strong (up to 9.5 magnitude). They may be deep which is why they might be weaker.

Question 18

Describe the earthquakes formed on a conservative plate boundary

Answer 18

Very strong earthquakes. They can be shallow, meaning that they will cause more damage. (up to 8.5 magnitude)

Question 19

How are Tsunamis formed

Answer 19

When an oceanic crust is jolted during an earthquake all the water above is displaced

Water travels fast but with low amplitude

As it gets closer to the coast the sea level decreases so there is friction between the sea bed and the waves

This causes waves to slow down and gain height creating a tsunami

Question 20

give 2 differences between a shield and composite volcano

Answer 20

At divergent boundaries the volcanoes are less steep , this is due to the runny lava which travels a greater distance before it solidifies.

● At divergent boundaries volcanic explosivity is lower , due to the magma having a lower gas content and it being less viscous