Unit 1A - the challenge of natural hazards (2. tectonic hazards)

Question 1

what is an earthquake?

Answer 1

violet period of ground shaking. commonly caused by a sudden movement of rocks within the earth’s crust.

Question 2

what are tectonic plates

Answer 2

earths crust is split into a number of plates about 100km thick

Question 3

what are the 2 types of crust

Answer 3

dense thin oceanic crust

less dense thick continental crust

Question 4

how do tectonic plates move

Answer 4

due to convection currents from deep within the earth.

Question 5

what happens at a constructive plate margin

Answer 5

plates move apart and magma rises creating a new crust.

Question 6

what happens at destructive plate margins

Answer 6

plates move towards each other the oceanic denser plate sinks beneath the less dense continental plate. the oceanic plate subducts into the mantle and is destroyed creating a gas rich magma. volcanoes and ocean trenches occur here.

Question 7

what happens at conservative plate margins

Answer 7

2 plates are moving sideways past each other or moving in the same direction of at different speeds. crust isn’t created or destroyed.

Question 8

what happens at collisional zones

Answer 8

2 continental plates move toward each other and created fold mountains

Question 9

what is a volcano

Answer 9

large and often conical shaped landform usually formed over a long period of time by a series of eruptions. Like earthquakes volcanoes occur in long belts that follow the plate margins.

Question 10

what is the pattern of volcanoes

Answer 10

volcanoes are fed by hot molten rock from deep within the earth. this rises to the surface at constructive and destructive plate margins. volcanoes are also formed at hotspots where the crust is thin and magma is able to break through.

Question 11

what is the mid Atlantic ridge

Answer 11

An area of volcanoes in the centre of the Atlantic Ocean.

Question 12

primary effects of earth quakes

Answer 12

death, injuries damage to roads, and damage to buildings

Question 13

secondary effects of earthquakes

Answer 13

RESULT OF PRIMARY EFFECTS

tsunami, fires, landslides

Question 14

what is chiles GDP

Answer 14

40th out of 195 countries

Question 15

what is Nepals GDP

Answer 15

110th out of 195 countries

Question 16

what is Chiles HDI

Answer 16

41st out of 187

Question 17

what is Nepals HDI

Answer 17

145th out of 187

Question 18

what is the date Chiles earthquake occurred on

Answer 18

2010

Question 19

what was Chiles earthquake on the Richter scale

Answer 19

8.8

Question 20

what plates were involved in the Chile earthquake

Answer 20

destructive plate margin, Nazca plate moves underneath South American plate
as the plate movement occurred in the Pacific Ocean a lot of sea water was displaced triggering a tsunami

Question 21

When did the Nepal Earthquake happen

Answer 21

2015

Question 22

magnitude of the Nepal Earthquake

Answer 22

7.9

Question 23

what caused the Nepal Earthquake

Answer 23

subduction of the Indo-australian plate beneath the Eurasian plate

Question 24

what was triggered due to the Nepal Earthquake

Answer 24

huge avalanches and landslides, the earthquake also spread 100km in to Tibet and Pakistan and India

Question 25

Primary effects of the Chile earthquake

Answer 25

• 500 killed
• 12000 injured
• many homes schools hospitals were damaged and the Santiago airport was also badly damaged
• water electricity and communications were lost.
• 30 billion USD of damage

Question 26

Secondary effects of the Chile earthquake

Answer 26

fires, landslides and tsunamis broke out

Question 27

Primary effect of the Nepal earthquake

Answer 27

• 9000 killed
• 20000 injured
• 3 million left homeless
• 7000 schools destroyed
• 50% shops destroyed
• power water communications effected
• 5 billion USD of damage
• 1.4 million urgently need of food and water and shelter

Question 28

Secondary effects of the Nepal effects

Answer 28

• landslides and avalanches triggered and people trapped under snow and rubble
• blocked rivers people needed to be evacuated

Question 29

immediate responses of Nepal Earthquake

Answer 29

international aid arrived quickly from china and India
helicopters were used to search for people
half a million tents were provided

Question 30

immediate responses of Chile Earthquake

Answer 30

emergency services deployed quickly
within 24hrs roads were temporarily repaired
temporary shelters were set up
power and water was repaired within 10 days
60 million USD raised to build shelters

Question 31

long term responses of Nepal Earthquake

Answer 31

roads repaired and landslides were cleared
thousands of homeless people re housed
7000 schools re built
government enforced stricter building codes

Question 32

long term responses of Chile Earthquake

Answer 32

month later reconstruction plans to help 200000 house holds

president announced it would take 4 years for Chile to fully recover

Question 33

how Many people live in seismically active areas

Answer 33

2.7 billion

Question 34

how many people live near dangerous volcanoes

Answer 34

400 million people

Question 35

benefits of living near volcanoes

Answer 35

lots of nutrients within volcanic material so this makes the soil fertile, agriculture is therefore a big source of income for people living near volcanoes, volcanic soils are the most fertile in the world

hazardous areas are also good tourism sights

Question 36

what is one bad reason why people do not move away from hazardous areas

Answer 36

some people may not have a choice and cannot afford to move away
some people may not be made aware that there is a tectonic hazard near by

Question 37

what are the 4 ways to reduce the effects of tectonic hazards

Answer 37

planning predicting monitoring protecting

Question 38

what is monitoring

Answer 38

using scientific equipment to detect warning signs of events such as volcanic eruption

Question 39

what is prediction

Answer 39

using historical evidence and monitoring scientists can make predictions about when and where a tectonic hazard may happen

Question 40

what is protection

Answer 40

designing building that can withstand tectonic hazards

Question 41

what is planning

Answer 41

identifying and avoiding places most at risk

Question 42

name some modern hi-tech equipment to monitor volcanic activity

Answer 42

remote sensing - satellites that detect changes and heat changes to a volcano

seismicity - seismographs record earthquakes

ground deformation - changes of the shape of the volcano are measured by laser beams

geophysical measurements - detects changes in gravity as magma rises to the surface

gas - instruments detect gases released as magma rises

hydrology - measurements of gases dissolved in water

Question 43

why do people choode to live in iceland despite the many active volcanoes

Answer 43

Over 320000 live in Iceland, there is an effective monitoring system and awareness of potential dangers.

Question 44

how does iceland benefit from tectonic activity

Answer 44

hot water from within the earths crust provides heat and hot water for nearly 90% of all buildings
thousands of tourists visit mount Eyjafijallajokull
geothermal energy is used for 25% of the country’s electricity