Natural Hazards - Tectonics

Question 1

Define natural Hazard.

Answer 1

An event beyond human control that could threaten both life and property.

Question 2

What is a secondary effect? +example

Answer 2

Happen later or often as a result of the primary effect.
eg. starvation, weakened econemy, spread of deseases

Question 3

Why do people live in tectonically active areas? (4)

Answer 3

• minerals from ash are good for fertile soil
• tourist attractions from volcanoes
• geothermal energy can be used = energy bills lower
• precious stones and minerals found neer volcanoes

Question 4

What is a natural disaster?

Answer 4

A natural disaster is the highly harmfull impact following a natural hazard event.

Question 5

Disadvantages of living in a tectonically active area. (3)

Answer 5

-ash pollutes rivers (may be source of food+water for area)
-houses may be destroyed by lava
-volcanoes can be deadly (few actualy die because of evacuation but you can be killed from lahars and pyroclastic flow)

Question 6

Explain ridge push.

Answer 6

1. crust is heated and expands to form a sloap
2. crust cools down and becomes dense
3. Gravity and the weight of the plate also make it move
   (@ constructive plate boundaries)

Question 7

Explain slab pull.

Answer 7

1. Convection currents move plates together
2. Oceanic plate subducts because its denser
3. This creates a fource that pulls this plate down further
   (@ destructive plate boundaries)

Question 8

What is a primary effect? + example

Answer 8

The immediate impacts caused by the natural hazard itself.
eg. people dying, houses colapsing, injured people

Question 9

What are the four ways management can reduce the effects of tectonic hazards?

Answer 9

Prediction
Protection
Monitoring
Planning

Question 10

Explain constructive plate boundaries.

(Arrows one)➝

Answer 10

Convection currents & ridge push ➝ apart ➝ gap ➝ magma➝ new crust➝surface of water➝ volcano
Apart ➝ fractures ➝ releases energy ➝ seismic➝ EQ’s

Question 11

Explain conservative plate boundaries.

(arrows one)➝

Answer 11

move➝side➝convection➝snag(get caught)➝ energy-in rock➝slip➝ released ➝ seismic waves ➝EQ’s

Question 12

Explain destructive plate boundaries.

(arrows one)➝

Answer 12

Together➝ convection currents➝ slab pull➝ meet➝ oceanic subducts➝ denser➝ mantle➝ magma➝ pressure➝ force crack➝ explode ➝ lava
Together➝ energy -in rock➝ slip➝ released➝ seismic waves➝ EQ’s

Question 13

What movement happens at conservative plate boundaries why? + Example place

Answer 13

Plates move side by side eachother because of convection currents.
Example: San Andreas fault line

Question 14

What movement happens at constructive plate boundaries why? + Example place

Answer 14

Plates move apart because of convection currents and ridge pull. Example: Mid atlantic Ridge.

Question 15

What movement happens at destructive plate boundaries why? + Example place

Answer 15

Oceanic plate subducts under continental plate becuae its denser. Moving because of ridge push and slab pull. Example: Pacific ring of Fire.

Question 16

What heats the mantle?

Answer 16

Radioactive decay occuring in the earths core.

Question 17

What is continental crust? (info)

Answer 17

Type of curst that is thicker, older and less dense.It has mainly landmass on it.

Question 18

Define protection.
+Example

Answer 18

Actions taken before a hazard strikes to reduce its imapct.
eg. educate people, reinforcing buildings.

Question 19

Define a secondary Hazard.

Answer 19

One that occurs because of another hazard. Eg. tsunami caused by an earthquake.

Question 20

Give four pieces of evidence for continental drift.

Answer 20

• sea shells on the top of the Hymalayas
• Fossils of land animals found across continents separated by the sea
• Jigsaws = continents fit together like a jugsaw.
• mountain ranges meet up when continents are placed together

Question 21

What can protection do for earthquakes and volcanoes?

Answer 21

Reduce the effect of tectonic hazards.
EQ’s - reinforce/strengthen buildings to absorbe EQ energy
Volcano - trenches to barrier from the lava, strengthen buildings from ash

Question 22

What can prediction do for earthquakes and volcanoes?

Answer 22

Reduce the effect of tectonic hazard
EQ- cant be reliably predicted but can monitor plate movement
Volcano - predicted if monitored closely

Question 23

What are some human factors that affect risk? (4)

Answer 23

Population density
Quality of buildings
Politics
Wealth

Question 24

What does monitoring do for earthquakes and volcanoes?

Answer 24

Reduce the effect of tectonic hazards
EQ- seismometers & lazers monitor earths movements.
Volcanoes- Monitor signs before an erruption= gas, shape change.

Question 25

What are convection currents & how do they work?

Answer 25

Currents in the earths mantle that move plates together/apart/ slide with eachother. 1. particles close to core are heated 2. they expand so are less dense so rise up. 3. particle cool down so sink 4. current is created as this repeats.

Question 26

What can planning do for earthquakes and volcanoes?

Answer 26

Reduce the effect of tectonic hazard. EQ+volcanoes -prepare emergency services -educate people -plan evacuation -stockpile emergency supplies.

Question 27

What is prediction?

Answer 27

Attept to forcast when and where natural hazard will be.

Question 28

What is planning?

Answer 28

Actions taken to enable communities to recover& respond to natural disasters.

Question 29

What are some physical factors that affect risk? (6)

Answer 29

Magnitude Location Landscape Time of day Frequency Seasons

Question 30

What is monitoring?

Answer 30

Recording physical changes ( like earthquake tremours around volcano) to help forcanst when and where natural hazard will be.

Question 31

What are some meteorological hazards + name some.

Answer 31

weather hazards caused by weather or climate process. Floods Tropical storms Doughts Landslides Sandstorms Thunderstorms

Question 32

Explain the two types of response.

Answer 32

Actions taken to deal with the consequence of event. Immediate response: in the days and weeks immediately after disaster happens Long term response: months and years after disaster.

Question 33

What are geological hazards? +name some.

Answer 33

geological/tectonic hazards caused by the earth and its tectonic plate movemments. Earthquakes, volcanic erruptions, Tsunamis

Question 34

What is oceanic crust?

Answer 34

Oceanic crust is a type of crust that is yonger, denser and thinner. With mainly ocean on it.

Question 35

What happens at conservative plate boundaries?

Answer 35

1. plates move side by **side** past eachother because of convection **currents** in the mantle. 2. **snag** on edges of rock- sharp uneaven. 3. **pressure** builds up 4. one slips and energy is **relased** in **seizemic** waves 5. causing earthquakes. **NO** VOLCANOES

Question 36

What happens at destructive plate boundaries?

Answer 36

1. convection currents push oceanic and continental plates **together** 2. Oceanic plate **subducts** because its **denser**& slab pull pulling it down. 3. mantle **melts** ocanic plate 4. magma **chambre** formed under pressure 5. **cracks** form from magma forcing its way up 6. magma **explodes** out in volcanoes as **lava** EQ- when plates slip

Question 37

What happens at constructive plate boundaries?

Answer 37

1.Convection currents in mantle & ridge push move plates apart. 2.Gap is created that is filled with magma 3.Over time plates move further apart, filled with magma and cooled by the sea. 4.when magma reaches surface of sea it doesnt cool so volcano is formed(sheild) EQ- plate fracture