Tectonic Hazards

Question 1

Tectonic plate

Answer 1

A large piece of earths crust

Question 2

Plate boundary

Answer 2

Where 2 tectonic plates meet

Question 3

Constructive/divergent plate boundary

Answer 3

Oceanic plates move apart, sea floor spreads and mid-ocean ridges are made as magma rises to fill the gap, underwater volcanoes formed, where 2 continental plates diverge rift valleys are formed

Question 4

Destructive plate boundary

Answer 4

Oceanic and continental plates move together, heavier oceanic plate sinks under continental and melts, it rises and breaks though the continental to make volcanoes and violent earthquakes, it is the most dangerous margin

Question 5

Collision plate boundary

Answer 5

Continental plates move together, too light to sink, buckle and fold to make fold mountains and earthquakes

Question 6

Conservative plate boundary

Answer 6

Plates moving different directions or speeds, lock together by friction, pressure builds, pressure released making earthquakes

Question 7

Characteristics of continental crust

Answer 7

Thicker, lighter, forms continents, granite

Question 8

Characteristics of oceanic crusts

Answer 8

Thinner, heavier, forms ocean bed, basalt

Question 9

Shield volcanoes

Answer 9

Formed in oceans(often constructive), rise from ocean floor, gentle upper slopes and steep lower slopes, made of lava flows built over a central vent, shield shaped

Question 10

Stratovolcanoes

Answer 10

Steeper slopes and narrower, steep slopes made of la a flows that don’t travel far, alternating layers of ash and lava, more explosive because of long dormant times, first explosive to open vent and then lava flows out

Question 11

Parts of a volcano

Answer 11

Conduit-where lava flows
Magma chamber-contains magma deep in earths crust
Side vent-vent on side of volcano

Question 12

Primary impacts of volcanoes

Answer 12

Lava, ash, pyroclastic flow, volcanic bombs

Question 13

Secondary impacts of volcanoes

Answer 13

Fire, lahars, landslides, trunamis

Question 14

How can impacts of eruptions be reduced

Answer 14

Diversion of lava flow with excavators, spray lava with water to solidify, build walls across valleys to stop mudflows, stronger buildings so they don’t collapse, monitor earthquakes or gas emissions, ban passage to hazard areas

Question 15

Hot spot

Answer 15

Volcano forms middle of a plate under the ocean, magma rises. In the middle of a plate, plate moves and another volcano in formed, string of islands

Question 16

What is an earthquake

Answer 16

Shaking and vibration of the ground caused by movements in the crust

Question 17

What is the focus of an earthquake

Answer 17

Point underground where shockwaves start

Question 18

What is the epicentre of an earthquake

Answer 18

Pint aboce ground right above focus where vibration is highest

Question 19

What is the richter scale

Answer 19

Scale that measures size of an earthquake, each point is 10x bigger than the last

Question 20

What is a seismograph

Answer 20

Apparatus than measures size of an earthquake and records it on a seismogram

Question 21

What affects the damage of an earthquake

Answer 21

The magnitude, the depth of focus, the population density, the time of day, the time it lasts

Question 22

Reducing the risk of earthquakes

Answer 22

Monitoring with tilt meters, costly methods that provide only few seconds warning, prepare disaster plans, educate people, organise emergency supplies, efficient warning centre, specially trained dogs to locate survivors, prepare buildings VS earthquakes