tectonics

Question 1

What is meant by the term plate boundary

Answer 1

where tow or more plates meet - name the plates

Question 2

name the 4 types of plate boundary

Answer 2

constructive
destrucitve
conservative
collison

Question 3

2 plates where the most powerful earthquakes occur

Answer 3

convergent

conservative

Question 4

2 plate boundaries where most volcanoes occur

Answer 4

convergent

diveregnt

Question 5

what are hotspot volcanoes and where do they occur

Answer 5

magma plume erupts through crust
middle of a plate
kileua hawaii

Question 6

describe the origins of the mid Atlantic ridge and how its associated with tectonic hazards

Answer 6

iceland
erasion plate and North American plate
divergent plate boundary
creates submarine volcanoes
sea floor spreading - harry hess

Question 7

why are some locations more at risk

Answer 7

on plate boundaries
ring of fire
distance from epicentre

Question 8

2 types of earths crust

Answer 8

oceanic- newer, thinner, denser - subducted

continental- older, thicker , less denser

Question 9

what causes tectonic plates to move

Answer 9

convection currents

Question 10

3 process at work along a destructive plate boundary

Answer 10

ridge push
slab pull
convection currents

Question 11

what is paleo magnetism

Answer 11

magnetic minerals in lava point in the same direction as the poles - aligned to earths magnetic polarity
poles are always alternating

Question 12

what is a locked fault

Answer 12

huge slabs of irregular shaped rock are stuck together
tectonic strain is produced
elastic energy
energy released
elastic rebound
a lot of damage

Question 13

what is the Benioff zone

Answer 13

friction occurs to produce earthquakes - ridge push and slab pull
oceanic plate is subducted - plate melts
destructive margin

Question 14

hypocentre and epicentre

Answer 14

hypocentre- in earths crust and this is where the waves are produced
epicentre - directly above the hypocentre but on the earths surface - most damage will occur there

Question 15

magnitude and intensity of an earthquake

Answer 15

magnitude - richter scale - how much energy is released from the erathquake
intensity - mercalli scale - how it affects the poeple surrounding it

Question 16

3 types of waves

Answer 16

p waves - primary, fastest, act like a slinky
S waves - secondary, slowest, move up and down
l waves - love, most damage, move side to side

Question 17

one secondary hazard with earthquakes

Answer 17

liquefaction- soil becomes unstable and pulls anything in (like quicksand)

Question 18

3 primary volcanic hazards and how each threatens people

Answer 18

volcanic bomb - large sound, causes distress
ash cloud - drops global temperature
pyroclastic flow - damages anything in its way

Question 19

what are jokulhaups

Answer 19

melted glacier
produces landslides and mud flows
floods everything

Question 20

1 secondary hazard from a volcanic eruption

Answer 20

pyroclastic flow

Question 21

are volcanic eruptions unique

Answer 21

yes

• long duration
• only hazard to erupt magma
• can find out what happens below the earths surface
• determine a lot of thins - age
• predictable - smoke

earthquakes

• can’t see what happens in the earth
• not as predictable