Keywords - tectonics

Question 1

Ash

Answer 1

Very small solid particles ejected from a volcano during an eruption

Question 2

Aseismic building design

Answer 2

A design for earthquake-resistant buildings which is developed to limit the potential damage to buildings to a tolerable level

Question 3

Athenosphere

Answer 3

The upper layer of the Earth’s mantle, where convection occurs

Question 4

Benioff zone

Answer 4

The linear zone where a descending oceanic plate is in contact with a continental plate as it is subducted. This is a zone. Of earthquake activity created by the two plates, which creates stresses and strains which are suddenly released.

Question 5

Collision plate margin

Answer 5

Where two plates are colliding into each other, which create fold mountains - usually continental and continental

Question 6

Convergent plate margin

Answer 6

Where the oceanic plate is subducted under a continental plate

Question 7

Composite cone volcano

Answer 7

Also known as a cone volcano, it has steep sides and its eruptions are explosive. It erupts low silica lava which is thick and sticky meaning it cannot run very far creating the steep sides.

Question 8

Conservative plate margin

Answer 8

Occurs where plates slide past each other in opposite directions or in the same direction but at different speeds. Friction is eventually overcome, and the plates slip past in a sudden movement. The shockwaves created produce an earthquake

Question 9

Constructive plate margin

Answer 9

Two plates moving away from each other

Question 10

Destructive plate margin

Answer 10

A destructive plate margin forms when an oceanic and continental plate moves towards each other. The heavier, denser oceanic plate subducts the continental plate. The oceanic plate melts and it sinks below the continental plate due to friction in the subduction zone and the heat of the mantle

Question 11

Divergent plate margin

Answer 11

Two plates moving away from each other

Question 12

Disaster

Answer 12

An event, such as an earthquake, that disrupts normal conditions to a point where a place or community cannot adjust and there is significant loss of life and injuries and financial cost.

Question 13

Earthquake seismic waves

Answer 13

The shockwaves created by the release of the tension at a focal point

Question 14

Epicentre

Answer 14

The point on the Earth’s surface directly above the hypocentre where the seismic energy is felt the most

Question 15

Focal depth

Answer 15

The depth at which an earthquake starts. It is divided into shallow, intermediate and deep. Shallow earthquakes have the greatest impacts

Question 16

Hazard

Answer 16

Something that has a negative impact on people in any way

Question 17

Hazard management cycle

Answer 17

A sequence of actions and decisions related to a place or area being prepared for or responding to the threat of a natural hazard

Question 18

Hazard profile

Answer 18

An analysis of different types of hazard or actual hazard events based on a range of criteria. This allows a useful comparison to be made

Question 19

Hot spot volcano

Answer 19

An intra-plate location, oceanic or continental, where magma from the mantle has broken through a weak point in the crust

Question 20

Hydro-meteorological hazards

Answer 20

Hazards associated with flowing water or the weather. These may combine with tectonic hazards, for example lahars

Question 21

Hypocentre

Answer 21

The point inside the crust where the pressure and seismic energy is released

Question 22

Intensity

Answer 22

The amount of damage creates by a tectonic event or other hazard

Question 23

intraplate

Answer 23

Tectonic activity that is found away from the plate boundaries and closer to the middle of a tectonic plate

Question 24

jokulhlaups

Answer 24

A tectonic hazard common in Iceland, where volcanic activity underneath ice caps creates large volumes of meltwater which suddenly burst out as floodwaters under the ice, when the water pressure reaches a certain level.

Question 25

Lahar

Answer 25

A mixture of meltwater from snow and ice on top of an active volcano and tephra from eruptions that travels very quickly down existing river valleys.

Question 26

Landslide

Answer 26

Are large masses of wet or dry rock and soil that fall, slide or flow very rapidly under the force of gravity. Landslides are common on tall, steep and weak volcanic ones.

Question 27

Lava flow

Answer 27

A mass of flowing or solidified lava

Question 28

Liquefaction

Answer 28

Occurs when vibrations or water pressure within a mass of soil cause the soil particles to lose contact

Question 29

Lithosphere

Answer 29

The rigid outer part of the Earth, consisting of the crust and upper

Question 30

Magnitude

Answer 30

The amount of energy released by a tectonic event

Question 31

Mantle convection

Answer 31

The movement of mantle material in cells when heated by radiation from the Earth’s core

Question 32

Mantle plumes

Answer 32

They are the hotter areas of the mantle that move upwards underneath the crust and push it up. They can cause weak points in the crust which can become hotspots.

Question 33

Mercalli scale

Answer 33

An earthquake intensity scale based on 12 levels of damage to areas

Question 34

Moment magnitude scale

Answer 34

The most accurate earthquake scale, it measures the total energy released by an earthquake

Question 35

Multiple hazard zones

Answer 35

A country or region that experiences several natural hazards, such as earthquakes, volcanoes, river floods

Question 36

Natural hazards

Answer 36

A physical geographical event, tectonic, hydrological, or meteorological, which has a negative impact of people through causing injury or death

Question 37

Paleomagnetism

Answer 37

When magmas and lavas solidify, the iron minerals in the rock align with the Earth’s magnetic field, permanently recording the direction.

Question 38

Pyroclastic flow

Answer 38

A very fast-moving cloud of superheated gases and ash travelling at ground level

Question 39

Sea floor spreading

Answer 39

The movement of the oceanic crust away from a constructive plate boundary

Question 40

Slab pull

Answer 40

At a subduction zone the descending part of the oceanic tectonic plate pulls the rest of the plate with it.

Question 41

Subduction

Answer 41

The process involving the descent of an oceanic plate into the upper mantle beneath a continental plate

Question 42

Transform margin

Answer 42

Where two plates meet at a major fault in the Earth’s crust

Question 43

Tsunami

Answer 43

A sequence of huge waves created by a large displacement of seawater, usually by an undersea earthquake.

Question 44

Volcanic explosivity index

Answer 44

The scale used to measure the magnitude of a volcanic eruption

Question 45

Water column displacement

Answer 45

The movement of a volume of seawater above the point at which the seabed was moved up or down by an earthquake event such as thrust

Question 46

Crustal fracturing

Answer 46

when two tectonic plates moving into or next to each other creates a locked fault. Produces lots of strain which builds up elastic energy. The pressure and energy exceeds the strength of the plates which results in the energy being released.

Question 47

Love waves

Answer 47

they come from the epicentre - only travel through crust, faster surface wave. They move from side to side as it moves forward. Causes the most damage due to longer wavelength and focus of energy at surface

Question 48

P- waves

Answer 48

Caused by compression pushing and pulling in the direction of travel. They are the fastest and arrive first

Question 49

S-waves

Answer 49

slower, only move through solid rock, up and down movement, only through crust