Tectonic Hazards and Natural Hazards

Question 1

What are the 4 layers of the Earth?

Answer 1

Core, crust and mantle

Question 2

What are the two types of core

Answer 2

Inner and outer core

Question 3

What is the inner core

Answer 3

The inner core is metallic and solid

Question 4

What is the outer core

Answer 4

The outer core is liquid

Question 5

What is the core

Answer 5

The core is the hottest part of the Earth’s layers

Question 6

What is the mantle

Answer 6

The mantle surrounds the core. It is a semi solid rock and can move.

Question 7

What is the crust

Answer 7

Another word for crust is lithosphere. The litosphere is a thin outer shell and is the layer we live on. It is between 50 to 200km thick and floats on the semi solid rock mantle. The lithosphere is also broken into large pieces called tectonic plates

Question 8

What are the two types of tectonic plate

Answer 8

Oceanic and continental plate

Question 9

What is the continental plate

Answer 9

They are thicker, older, less denser and do not sink (subduct)

Question 10

What is the oceanic plate

Answer 10

They are thinner, younger, denser and sink (subduct)

Question 11

What are the three types of plate margin

Answer 11

Destructive/convergent
Constructive/divergent
Conservative

Question 12

What happens at a constructive plate margin

Answer 12

At a constructive plate margin, the plates move apart (divergent). The convection currents diverge (push apart) and cause a gap to form between the plates. Magma rises up to fill the gaps created between the plates.

Question 13

What happens at a destructive plate margin

Answer 13

At a destructive plate margin, the plates move towards each other(convergent)

The oceanic plate slides beneath the continental plate. This is where
subduction takes place.
The rocks catch against each other as the plates are not smooth surfaces. The pressure between plates builds up until the plates cannot take any more stress. They slip past each other, causing plate movement, and result of an earthquake

Question 14

What happens at a conservative plate margin

Answer 14

At a conservative plate margin, plates move sideaways. The plates do not move smoothly and get stuck due to friction. When the pressure builds up and the plates slip, it causes an earthquake. Conservative plate margins are also called passive or transform faults

Question 15

What is a tsunami

Answer 15

Tsunamis are huge waves that form when tectonic activity happens on seabed. They do not function like regular waves. They surge up to 30 metres high and cause devastation when hitting land

Question 16

What does tectonic activity mean

Answer 16

It causes water to be displaced. A wave will start from where the water was displaced before moving outwards

Question 17

What is an earthquake

Answer 17

A sudden or violent movement within the Earth’s crust followed by a series of shocks. An earthquake occurs when the Earth’s plates move and causes the ground to shake

Question 18

How do they happen at constructive plate margins

Answer 18

Pressure builds up from the cracks in the plate when moving apart

Question 19

How do they happen at destructive plate margins

Answer 19

The oceanic plate gets stuck as it moves under another.

Question 20

How do they happen at conservative plate margins

Answer 20

There is friction between the plates as they aren’t smooth. This causes earthquakes

Question 21

What are the initial consequences of an earthquake

Answer 21

Crustal fracturing
Ground shaking
Tsunamis
Lanslides

Question 22

Why are large landslides affective

Answer 22

Developing countries struggle to recover from landslides due to the lack of resources and infrastructure

Question 23

What are sub marine earthquakes

Answer 23

Results in tsunamis with devastating effects

Question 24

What are consequences of ground shaking

Answer 24

Severity and duration based on the magnitude of the earthquake and distance of the epicentre

Question 25

What are consequences of crustal fracturing

Answer 25

Deep fissures in the ground are created

Question 26

What are the two aspects of an earthquake

Answer 26

Focus and epicentre

Question 26

What is the point directly above the centre of the earthquake above the earth surface

Answer 26

Epicentre

Question 27

What causes pressure to be released under ground where energy radiates out.

Answer 27

Focus

Question 27

What is a volcano

Answer 27

A mountain or hill, typically conical, having a crater or vent through which lava, rock fragments, hot vapour, and gas are or have been erupted from the earth’s crust.

Question 28

What are the five products formed during a volcanic eruption

Answer 28

Lava
Gases
Ash
Pyroclastic flow

Question 29

What gas is emitted

Answer 29

Sulfur

Question 30

What is lava

Answer 30

Lava is the magma (molten rock) above the surface of the Earth

Question 31

What is ash

Answer 31

Ash is tiny pieces of burnt rock fragments that are blown in the atmosphere at some force. The pieces fall on land and float on air causing a volcanic winter

Question 32

What is a volcanic winter

Answer 32

During a volcanic eruption, it produces lots of ash and blocks the sun. Mount Pinatubo’s 1991 eruption reduced global temperature for 3 years

Question 33

What are pyroclastic flows

Answer 33

Pyroclastic flows are currents of hot ash, lava and gas that move downhill at speeds of up to 500km during an eruption. They are impossible to outrun and reach temperatures of up to 1000 degrees Celsius and covers distances of up to 30km from the volcano

Question 34

What are shield volcanoes

Answer 34

Shield volcanoes are found at divergent/constructive plate margins or hotspots (Pacific). They aren’t mainly explosive and release basaltic lava when a volcanic eruption is in progress. Basaltic lava is a liquid that flows gradually creating a volcano with a gentle gradient (rather than steep slope). These volcanoes do not produce ash

Question 35

How do volcanoes happen at divergent plate margins

Answer 35

Tectonic plates move away from one another to produce volcanoes. Hot magma rises from the mantle at mid ocean ridges, pushing the plates apart

Question 36

How do volcanoes happen at convergent plate margins

Answer 36

Convergent boundaries known as subduction zones create volcanoes by forcing the oceanic plate under the continental plate, melting the plate and creating pressure which results in a volcano. Where oceanic plates converge with continental plates, ocean sediments are pushed underneath the continental plate

Question 37

Do conservative plate margins occur at volcanoes

Answer 37

No they don’t