6. managing natural hazards

Question 1

supervolcano

Answer 1

a volcano that erupts at least 1000 km^3 of material

Question 2

natural hazard

Answer 2

a naturally occurring event that will have a negative impact on people

Question 3

risk

Answer 3

the probability of a natural hazard occuring and the losses or damages that might result from that

Question 4

natural disaster

Answer 4

when a natural hazard causes damage and the people affected are unable to cope

Question 5

vulnerability

Answer 5

the characteristics and circumstances of people in a community that make them susceptible to the impacts of a natural hazard

Question 6

plate tectonics

Answer 6

a theory developed in the 1960s that helps explain the formation of some of the important features on the earth’s surface and how the continents move

Question 7

fold mountain

Answer 7

mountains created where two or more tectonic plates are pushed together compressing the rocks and folding them upwards

Question 8

asthenosphere

Answer 8

the layer of the earth below the lithosphere which is hotter and weaker than the lithosphere above and is capable of plastic flow

Question 9

sima

Answer 9

another name for oceanic crust which is run in silicate and aluminium minerals

Question 10

sial

Answer 10

another name for continental crust, which is rich in silicate and aluminium minerals

Question 11

tectonic plate

Answer 11

a piece of lithosphere that moves slowly on the asthenosphere, seven major, eight minor, and numerous microplates have been identified

Question 12

lithosphere

Answer 12

outer and rigid layer of the earth comprising of the crust and upper part of the mantle

Question 13

convection currents

Answer 13

transfer heat from place to place, denser colder fluid sinks into warmer areas, heat from the earth’s core causes convection currents in the mantle

Question 14

plate boundary

Answer 14

where two or more plates meet (main types - constructive, destructive, conservative)

Question 15

sea-floor spreading

Answer 15

the process by which oceans are formed at a constructive plate boundaries, new oceanic crust is formed as two oceanic crusts move apart

Question 16

ridge push

Answer 16

a gravitational force that causes an oceanic plate to move away from the crest of a mid-ocean ridge and into a subduction zone, it works together with slab pull

Question 17

slab pull

Answer 17

the force at a destructive plate boundary, where the oceanic plate sinks beneath the adjacent plate, as a result of its own weight, the descending plate is pulled by a gravity through the asthenosphere

Question 18

subduction zone

Answer 18

a zone where the oceanic plate is deflected down into the mantle and at the surface, the subduction zone coincided with ocean trenches

Question 19

ocean trench

Answer 19

a depression of the ocean floor that runs parallel to s destructive plate boundary

Question 20

Benioff zone

Answer 20

a zone of earthquake foci in the upper part of a subducting oceanic plate at a destructive plate boundary

Question 21

island arc

Answer 21

a chain of volcanoes generally with an arc shape that run parallel to an oceanic trench at a destructive plate boundary

Question 22

collision zone

Answer 22

a destructive plate boundary between two continental plates resulting in fold mountains

Question 23

collision zone

Answer 23

a destructive plate boundary between two continental plates resulting in fold mountains

Question 24

richer scale

Answer 24

a measure of the magnitude of an earthquake taken with a seismograph

Question 25

liquefaction

Answer 25

the process where loose sediments with a high water content behave like a liquid when shaken by an earthquake

Question 26

tsunami

Answer 26

a large wave created by ocean floor displacement or landslides

Question 27

pyroclastic material

Answer 27

very hot gases ash and volcanic bombs

Question 28

lahars

Answer 28

mudflows of volcanic material caused when ask mixes with heavy rain or water from melting snow

Question 29

inter tropical convergence zone (ITCZ)

Answer 29

a low-pressure belt that lies around the equator where north-east and south-east trade winds meet, it receives high precipitation because of intense heating from the sun

Question 30

el nino southern oscillation (ENSO)

Answer 30

the change in the prevailing winds that leads to a change in the pattern in the currents in the oceans of the south pacific