Tectonic Hazards Flashcards Preview

Geography > Tectonic Hazards > Flashcards

Flashcards in Tectonic Hazards Deck (34)
Loading flashcards...
1
Q

What are the two main types of natural hazards?

A
  • Geological Hazards

* Meteorological Hazards

2
Q

What is the cause of Geological Hazards?

A
  • Caused by land and tectonic processes

* E.g. volcanoes, earthquakes, landslides, avalanches

3
Q

What is the cause of Meteorological Hazards?

A
  • Caused by weather and climate

* E.g. tropical storms, heatwaves, cold spells, climate change

4
Q

What are the factors affecting the Hazard Risk?

A
  • Capacity to Cope
  • Vulnerability
  • Nature of Natural Hazards
5
Q

What is a Hazard Risk?

A

Probability that a natural hazard occurs

6
Q

How does Vulnerability affect the Hazard risk?

A
  • More people in exposed area, greater probability they will be affected by a natural hazard - hazard risk higher
  • E.g. City at base of volcano (Naples) very vulnerable to volcanic eruptions
7
Q

How does Capacity to Cope affect the Hazard risk?

A
  • The better population can cope w/ extreme event, the lower the threat
  • If used to hazard then your resilient to hazard
  • E.g. HICs more able to cope with flooding because they can afford flood defences, etc
8
Q

What are the different type of Plate Margin?

A
  • Destructive Margins
  • Constructive Margins
  • Conservative Margins
  • Collision Plate Margins
9
Q

What are Destructive Margins?

A

•2 plates moving towards eachother

10
Q

What are Constructive Margins?

A

Two plates moving away from each other

11
Q

What are Conservative Margins?

A
  • Two plates are moving sideways past eachother

* Two plates moving in same direction but at different speeds

12
Q

What are Collision Plate Margins?

A

•Two plates made from continental crust and move towards each other

13
Q

How are Earthquakes caused?

A
  • Tension that builds up at Plate Margins

* Plates jerk past each other, sending shock waves, these vibrations are the earthquake

14
Q

How are Earthquakes measured?

A
  • Moment magnitude scale

* Richter scale

15
Q

What are Tsunamis and how are they caused?

A
  • Series of enormous waves

* Caused when huge amounts of water get displaced

16
Q

How can Earthquakes cause Tsunamis?

A
  • Underwater earthquakes cause seabed to move, displaces water
  • Waves spread out from epicentre of earthquake
  • Shallow force earthquakes displace more water because they are closer to Earth surface = bigger tsunami
17
Q

How are Volcanoes formed at Destructive Margins?

A
  • Oceanic plate under continental plate because more dense
  • Oceanic plate moves into mantle, where melted and destroyed
  • Pool of magma forms
  • Magma rises through cracks in vents
  • Magma erupts on surface (lava)
  • Forming volcano
18
Q

How are Volcanoes formed at Constructive Margins?

A
  • Magma rises up into gap created by plates moving apart

* Forming volcano

19
Q

What are Composite Volcanoes?

A
  • Occur at destructive plate margins
  • Water reacts with Magma, creates gases, subducted crust erupts
  • Ashy explosion, erupt andesitic lava (high silica content - thick/sticky)
  • Lava can’t flow far so form steep-sides cone
20
Q

What are Shield Volcanoes?

A
  • Occur at hotspots or constructive plate margins
  • Not explosive, only lava
  • Erupt basaltic lava (low silica content - runny)
  • Flow quickly and spreads over wide area so form low, gentle-sided volcano
21
Q

What are the Primary Effects of Earthquakes?

A
  • Bridges, buildings collapse - people injured from this
  • Homes destroyed
  • Roads, railways, airports damaged
  • Electricity cables, gas, water pipes, communication networks damaged
22
Q

What are the Secondary Effects of Earthquakes?

A
  • Leaking gas ignited, start fire
  • People homeless and could die
  • Shortage of clean water/lack of sanitation - diseases spread
  • Business destroyed - unemployment
  • Trigger landslides/tsunamis - destroy more buildings - more deaths and injuries
23
Q

What are the Immediate Responses to Earthquakes?

A
  • Rescue trapped people
  • Recover dead bodies to prevent diseases being spread
  • Put our fires
  • Set up temporary shelters
  • Provide temporary supplies of water, food, electricity, gas, communication systems
  • Foreign government send aid workers, supplies, equipment, financial donations
24
Q

What are the Long-Term Responses to Earthquakes?

A
  • Re-house people who lost home
  • Repair/Rebuild damaged buildings,roads,railways,bridges
  • Reconnect broken electricity, water
  • Improve building regulations so resistant to damage from earthquakes
  • Set up initiatives to help economic recovery
25
Q

What are the Primary Effects of Volcanic Eruptions?

A
  • Buildings/roads destroyed by lava flows
  • People/animals killed by lava flows or falling rocks
  • Crops damaged
  • People/animals/plants suffocated by volcanic gases
26
Q

What are the Secondary Effects of Volcanic Eruptions?

A
  • Mudflows and landslides cause death or injury
  • Flooding from hot rock/ash clogging up rivers and dams
  • Transport networks blocked - trade difficult
  • People left homeless
  • Ash makes field more fertile
27
Q

What are the Immediate Responses to Volcanic Eruptions?

A
  • Evacuate People - Provide food, drink, shelter for them
  • Treat injures People
  • Rescue anyone cut off by damaged roads
  • Provide temporary supplies of electricity,etc
  • Foreign governments send aid workers, supplies, equipment
28
Q

What are the Long-Term Responses to Volcanic Eruptions?

A
  • Repair/rebuild buildings,etc
  • Resettle affected people
  • Improve, repair, update monitoring/evacuation plans
  • Boost economy
29
Q

Why do people choose to Live Close to Volcanoes?

A
  • They have always lived there
  • They’re employed in the area
  • They’re confident of support from government
  • Volcanoes are tourist attractions
30
Q

How can you Reduce the Effects of Tectonic Hazards?

A
  • Management strategies

* Reduce number of people killed, injured, made homeless, made unemployed

31
Q

How can Monitoring help Reduce the effect of tectonic hazards?

A
  • Network of seismometers & lasers monitor earth movements - gives small warning
  • Scientists monitor tell-tale signs that come before volcanic eruption
32
Q

How can Prediction help Reduce the effect of tectonic hazards?

A
  • By monitoring movement of plates, forecast which areas should be prepared
  • Predicted If volcano well-monitored
  • Give time for people to evacuate
33
Q

How can Protection help Reduce the effect of tectonic hazards?

A
  • Buildings designed to withstand earthquakes, use reinforced concrete
  • Automatic shut-off switches to turn off gas & electricity to prevent fires
34
Q

How can Planning help Reduce the effect of tectonic hazards?

A
  • Future development avoid areas most at risk
  • Educate people so they know what to do If eruption occurs
  • Emergency supplies stockpiled
  • Government plan evacuation routes