Geography Natural Hazards (Tectonic Hazards)

Question 1

Fold mountains form when…

Answer 1

two continental plates converge AT A COLLISION PLATE MARGIN, forcing the crust upwards into mountains

Question 2

Layers of the earth are… and are made of…

Answer 2

Crust (rock), upper & lower mantle (semi liquid layer of molten magma), outer core (liquid iron and nickel) and inner core (solid iron)

Question 3

Stratocones are…

Answer 3

Cone shaped volcanoes found at destructive margins with steep sides and made of layers of ash and lava. They are made of viscous acidic lava, and erupt violently but infrequently, eg. Mt Pinatubo

Question 4

Shield volcanoes are…

Answer 4

Dome shaped volcanoes formed at constructive margins with gentler sloping sides due to being made of runny, basic lava which can flow further. Erupt less violently but more frequently

Question 5

What is a constructive plate boundary?

Answer 5

Where two tectonic plates move AWAY from each other. Magma rises to fill the gap, new land is created, features like shield volcanoes formed. Eg. Atlantic Ridge

Question 6

What is a destructive plate boundary?

Answer 6

Where two plates converge and the OCEANIC PLATE goes UNDER the CONTINENTAL PLATE. Landforms such as stratocones can be formed, as well as earthquakes. Eg. Himalayas

Question 7

What is a conservative plate boundary?

Answer 7

Where two tectonic plates slide past each other, and can be in opposite directions or the same direction but at DIFFERENT SPEEDS. Does not form volcanoes, but can often cause violent earthquakes due to sudden slips, eg. San Andreas Fault, California

Question 8

What is continental crust?

Answer 8

Quite think (20 - 70 km), but not very dense. Mostly made of granite

Question 9

What is oceanic crust?

Answer 9

Much denser and thicker than continental crust, however not very thick, (5 - 10 km). It is subducted UNDERNEATH continental crust

Question 10

What are the 4 main management strategies for reducing risk from tectonic hazards?

Answer 10

• Monitoring
• Prediction
• Protection
• Planning

Question 11

Ways to monitor volcanoes?

Answer 11

• Remote sensing (through satellites)
• Seismicity
• Ground deformation
• Geophysical measurements (changes to gravity as magma rises)
• Gas detection
• Hydrology (gas dissolved in water)

Question 12

What is prediction based on?

Answer 12

MONITORING

Question 13

How can we divert lava flow from property?

Answer 13

Earth Embankments or Explosives, (eg. Mt Etna)

Question 14

How can buildings be protected from earthquakes?

Answer 14

• Reinforced Walls
• Shock Absorbers
• Automatic Shutters
• Open Areas (for evacuation)
• Rolling weights on roof to counteract shock waves

Question 15

What are plate margins?

Answer 15

Where tectonic plates meet

Question 16

Causes and background of Haiti Earthquake 2010

Answer 16

• 2010
• Poorest country in Western hemisphere
• Magnitude 7
• Epicentre just 24km South of Port-au-Prince
• Shallow focus of 13km
• On conservative plate margin between NA plate and Caribbean plate

Question 17

Social impacts of Haiti 2010

Answer 17

• More than 300,000 buildings collapsed
• 1.3 million made homeless
• Around 300,000 people died

Question 18

Economic impacts of Haiti 2010

Answer 18

• 30,000 commercial buildings collapsed
• Port and airport damaged
• $7.8 - $8.5 billion in damage

Question 19

Environmental impacts of Haiti 2010

Answer 19

• Small landslides

- Oil spills

Question 20

Short term responses to Haiti 2010

Answer 20

• Dominican Republic supplied water, medical supplies and machinery
• Rescue teams, such as Red cross arrived from many countries
• USA provided rescue teams and 10,000 troops

Question 21

Long-term responses to Haiti 2010

Answer 21

• Governments and organisations donated $13.5 billion
• Appeals in other countries were launched
• Ports, new homes and schools were rebuilt
• Small farmers were supported

Question 22

Why was Haiti affected so badly?

Answer 22

Lack of regulation due to poverty

2/3 of population were unemployed before the quake, so recovery was poor

Government had little money so facilities such as emergency services were poor

1/2 of Haiti’s population was poor so facilities were poor

Question 23

How does being in poverty affect risks to natural disasters?

Answer 23

Limited resources, lack of education and health services can increase exposure to risks

Question 24

Primary Effects of Eyjafjallajökull

Answer 24

Eruption turned day to nigh because of the ash clouds

Plane flights were cancelled

Homes and roads were destroyed

Question 25

Secondary effects of Eyjafjallajökull

Answer 25

Sporting events were cancelled due to cancelled flights, which impacted tourism industries

Fresh food imports were halted

Local water supplies were contaminated by fluoride

Flooding was caused by glaciers melting

Europe lost over 6 million per day from loss in tourism

Worldwide, businesses lost billions

Question 26

Immediate responses to Eyjafjallajökull

Answer 26

State of emergency was declared

EU airspace was closed as a safety precaution

Evacuation of the people happened before the volcano erupted

Question 27

Long term responses to Eyjafjallajökull

Answer 27

Properties were to be rebuilt

Restoration of utilities

Developing opportunities for economy to recover

Question 28

What are some relief efforts for future earthquakes in Haiti?

Answer 28

Micro-credit schemes, where charity donates money to civilians to begin a working life

Improvements to buildings where more civilians can live in stable and safe housing

Crop trials were Oxfam invests in making the farmer’s product better to increase efficiency