Theme 3 - Vulnerabilty and hazard reduction

Question 1

Volcanic explosivity index?

Answer 1

a measure of the explosiveness of volcanic eruptions on a scale of 1-8.

Question 2

Magnitude?

Answer 2

a quantitative measure of the size of an earthquake using the Richter scale.

Question 3

Richter scale?

Answer 3

a measure of the magnitude of an earthquake on a scale of 1-10.

Question 4

Lava flow?

Answer 4

a stream of lava flowing from a volcanic vent.

Question 5

Ash cloud?

Answer 5

a large cloud of smoke and debris that forms over a volcano after it erupts.

Question 6

Pyroclastic flow?

Answer 6

the cloud of gas, ash, dust, stones and rocks emitted during a highly explosive volcanic eruption.

Question 7

Lahar?

Answer 7

mudflow associated with volcanic activity.

Question 8

Liquefaction?

Answer 8

occurs when vibrations cause soil particles to lose contact with one another, as a result soil behaves like a liquid and can flow down very gentle slopes.

Question 9

Tsunami?

Answer 9

a long, high sea wave caused by an earthquake or other disturbance.

Question 10

What are 4 physical factors that increase vulnerability to earthquakes?

Answer 10

.ground movement and shaking
.soil liquefaction
.landslides
.tsunamis

Question 11

How vulnerable to tectonic activity a region is depends on: ? (4)

Answer 11

.magnitude
.duration
.predictability
.regularity

Question 12

Vulnerability?

Answer 12

the potential to be harmed by a natural hazard.

Question 13

Aftershocks?

Answer 13

ground tremors occuring after a major earthquake but associated with the same focus.

Question 14

Capacity?

Answer 14

the ability of a country or region to react to and recover from a natural hazard.

Question 15

Focus?

Answer 15

the source of a shockwave, which can be at varying depths.

Question 16

Epicentre?

Answer 16

the point on the earth’s surface immediately above the focus.

Question 17

What are social and economic human factors that increase vulnerability? (7)

Answer 17

.wealth
.education
.goverments
.age
.health
.population
.time of day
.emergency services

Question 18

Seismometer/seismograph?

Answer 18

an instrument used to detect and record earthquakes.

Question 19

Hazard map?

Answer 19

a map that highlights areas affected by or vulnerable to a particular hazard.

Question 20

Risk?

Answer 20

the probability of a hazard event causing a harmful consequences.

Question 21

What are some earthquake monitoring techniques? (3)

Answer 21

.laser beams - detect plate movement
.seismometer/seismograph - detect vibrations in earth’s crust
.levels of radon gas escaping from cracks in the earth’s crust

Question 22

What are some volcanic eruption monitoring techniques? (4)

Answer 22

.remote sensing - satellites monitor gas emissions and use thermal imaging
.visual signs - cameras are used to look for visual signs of change in the volcano
.seisometers - measure earthquake activty that may lead to an eruption of a volcano
.gas emissions - these increase before an eruption

Question 23

How are hazard maps useful to local authorities? (2)

Answer 23

.limit access to hazardous areas
.control development in areas at risk from tectonic events

Question 24

Emergency planning (7)

Answer 24

.exclusion zones set up near a volcano
.evacuation routes
.lava flows can be diverted
.emergency services trained to handle disasters
.people can be educated through TV, social media, and school
.people may put together emergency kits to store at home
.roads and bridges can be designed to withstand the power of earthquakes