Paper 1 -Section A, Tectonic Hazards

Question 1

What is the definition for natural hazards

Answer 1

Natural hazards are extreme natural events that can cause loss of life, extreme damage to property and disrupt human activities

Question 2

What factors can affect hazard risk

Answer 2

Type of Hazard - some are hard to predict (more risky)

Economic Development- richer countries can afford prediction, protection and planning

Population Density- the more people in a crowded space, the higher the death toll

Severity - some natural hazards are more severe than others (eg a higher magnitude)

Question 3

Explain the distribution of earthquakes and volcanoes through plate tectonics theory

Answer 3

• mainly distributed along plate margins, where 2 or more plates meet
• plate tectonics theory = plates move against each other and this generates lots of energy, this energy is what causes earthquakes and volcanoes to form

Question 4

What is a constructive plate margin

Answer 4

• the plates move apart and magma rises to fill the gap
• usually found under the sea
• ridges and shield volcanoes are formed due to the build up of magma
• shallow minor earthquakes can occur along cracks in plates as they move apart

Question 5

What is a destructive plate margin

Answer 5

• plates move together
• lighter continental crust stays on top, the denser oceanic crust is subducted into the mantle, where it melts
• rising magma from melting crust causes composite volcanoes
• energy builds up and causes violent eruptions

Question 6

what is a conservative plate margin

Answer 6

• the plates slide past each other
• there are violent earthquakes as the plates get ‘stuck’ causing pressure to build up, then when plates ‘unstick’, causes a release of energy and pressure causing an earthquake

Question 7

Why do people choose to live near ares of risk of tectonic hazards

Answer 7

• volcanic soils are very fertile and good for farming
• risk may seem low because tectonic hazards have been rare in the past
• industries like tourism and mining offer employment
• geothermal energy can be accessed in tectonically active areas

Question 8

How can we reduce the risk of tectonic hazards using Prediction

Answer 8

• use scientific equipment to detect warning signs so that experts can make predictions
• although, it is impossible to make accurate predictions about earthquakes
• scientists can use historical data to predict locations at highest risk

Question 9

How can we reduce the risk of tectonic hazards using Protection

Answer 9

• design buildings and infrastructure that can withstand the effects of a tropical storm or earthquake
• this is the main way to reduce risk
• construct buildings which resist ground shaking

Question 10

What can we do to help reduce the risk of a tectonic hazard by designing buildings to withstand tectonic hazards

Answer 10

• build tsunami walls to protect people and important buildings
• build earthquake resistant buildings:

crossing bracing - reinforcing walls using 2 steel beams

shock absorbers - absorb tremors of earthquakes

shear walls - (concrete walls with steel bars) to reduce rocking movements

Question 11

What can we do to reduce the risk of tectonic hazards with Preparation

Answer 11

• identity places most at risk and prepare population on how to respond
• evacuation plans set up routes for people to escape
• citizens and emergency services practice drills
• educate people on what to do ( eg how to turn off gas and electricity in the event of an earthquake to reduce the risk of fire)

Question 12

Main facts about Chile 2010 earthquake

Answer 12

• 8.8 magnitude
• HIC
• destructive plate margin

Question 13

What are the Primary effects after the Chile 2010 earthquake

Answer 13

• 500 people were killed
• 12,000 injured
• water, electricity and communications were lost in many places
• estimated cost USD$30 billion
• well constructed buildings were left standing

Question 14

What are the secondary effects of the Chile 2010 earthquake

Answer 14

• Landslides triggered by earthquake damaged 1500km of road, debris blocked roads for weeks which left rural communities cut off
• A tsunami was triggered by the earthquake and destroyed coastal towns
• Fires broke out in buildings due to burst pipes and other complications meaning people had to be evacuated

Question 15

What were the immediate responses to the Chile 2010 earthquake

Answer 15

• Emergency services were deployed quickly
• Search and Rescue teams were sent out to search and help for survivors
• Emergency fields hospitals were set up
• Within 24 hours, Route 5 highway had temporary repairs and this allowed response teams to access remote areas
• Power and water restored to 90% of homes within 10 days
• International aid groups set up emergency response units for healthcare and supplies distribution

Question 16

What were the Long-Term responses to the Chile 2010 earthquake

Answer 16

• a month after the earthquake, the government launched a plan to reconstruct 200,000 homes
• Foreign aid was not heavily relied upon as Chile had the funds for reconstruction and recovery
• President announced it would take 4 years to recover completely, main focus on rebuilding ports so exports could resume

Question 17

What is the definition of primary effects

Answer 17

Primary effects happen immediately as a result of a tectonic hazard. For example, deaths, injuries and destruction/damage of buildings

Question 18

What is the definition of secondary effects

Answer 18

Secondary effects are the after-effects of a tectonic hazard, often resulting from primary effects. For example, spread of diseases when sewer systems and clean water supplies break down or fires caused by fractured gas pipes

Question 19

What are some of the main facts of the Nepal 2015 earthquake

Answer 19

• 7.8 magnitude
• LIC
• destructive plate margin

Question 20

What were the primary effects of the Nepal 2015 earthquake

Answer 20

• 9,000 killed
• 20,000 injured
• 3 million people were left homeless
• power, water and communications were severely damaged
• the cost was USD$5 billion
• 50% of all shops were destroyed leading to food shortages

Question 21

What were the secondary effects of the Nepal 2015 earthquake

Answer 21

• Landslides and Avalanches left widespread damage to infrastructure, blocking roads and trapping people under rubble and snow
• Avalanches on Mt Everest killed at least 19 people and hundreds were left missing
• Landslides blocked rivers, many had to be evacuated in case of flooding

Question 22

What were the immediate responses to the Nepal 2015 earthquake

Answer 22

• International aid arrived quickly from Uk, China and India
• Helicopters were used for search and rescue and supply distribution
• 500,000 tents were supplied by UNICEF which provided shelter for the homeless, temporary classrooms and healthcare facilities
• 300,000 people fled Kathmandu (capital)

Question 23

What were the Long-term responses to the Nepal 2015 earthquake

Answer 23

• In 2019, 3/4 of homes were either fully rebuilt or under repair
• Government introduced stricter building codes with better earthquake resistance
• Landslides were cleared and roads were repaired
• Repairs to Everest base camp and mountain routes in the same year, meant that open for mountain climbers and tourist
• June 2015 Nepal hosted international conference for advice and financial support from other countries to help recovery process