Chapter 6: Managing natural hazards

Question 1

Q: What materials make up the Earth’s inner core?

Answer 1

A: Iron and nickel.

Question 2

Q: What is the state of the Earth’s outer core and its temperature range?

Answer 2

A: The outer core is liquid and has a temperature range of 4000 – 5000°C.

Question 3

Q: What type of materials is the Earth’s mantle composed of?

Answer 3

A: Mainly silicate minerals.

Question 3

Q: What are some methods to manage drought?

Answer 3

A: Increasing water supplies, water conservation, agricultural improvements, and government stockpiling supplies.

Question 3

Q: What causes tectonic plates to move?

Answer 3

A: Convection currents in the mantle.

Question 4

Q: What geological feature can form when two oceanic plates move apart?

Answer 4

A: New basaltic ocean crust, shields or basic volcanoes, and sea-floor spreading.

Answer 4

A: It causes warmer surface waters in the Pacific, leading to droughts in Australia.

Question 4

Q: What is a constructive (divergent) plate boundary?

Answer 4

A: A boundary where two tectonic plates move away from each other.

Question 4

Q: What is the focus of an earthquake?

Answer 4

A: The point where the earthquake begins underground.

Question 5

Q: Why do tropical cyclones not form on the equator?

Answer 5

A: Because the Coriolis effect at the equator is zero, preventing the rotation necessary for cyclones.

Question 5

Q: What happens at a destructive (converging) plate boundary?

Answer 5

A: Two plates move towards each other, resulting in subduction, formation of an ocean trench, volcanic activity, and sometimes fold mountains.

Question 5

Q: What is a conservative plate boundary?

Answer 5

A: A boundary where two plates slide past each other, causing earthquakes due to pressure build-up.

Question 5

Q: Where are volcanoes most commonly found?

Answer 5

A: On constructive and destructive plate boundaries and hotspots.

Question 6

Q: How can deforestation contribute to flooding?

Answer 6

A: It reduces interception and infiltration, leading to increased overland flow.

Question 6

Q: What effect does climate change have on droughts?

Answer 6

A: Warmer temperatures can lead to decreased rainfall and increased drought conditions.

Question 6

Q: What is the epicenter of an earthquake?

Answer 6

A: The point on the surface directly above the focus.

Question 6

Q: What are some physical causes of flooding?

Answer 6

A: Heavy rainfall, prolonged rainfall, snowmelt, land relief, and saturated soil.

Question 6

Q: What are some opportunities presented by natural hazards?

Answer 6

A: Fertile soils after volcanic eruptions, geothermal energy, mining opportunities, scenic beauty, and potential employment opportunities.

Question 7

Q: What is the state of the Earth’s mantle and its temperature range?

Answer 7

A: The mantle is solid but flows slowly due to convection currents, with a temperature range of 1000 – 1200°C.

Question 7

Q: What are the primary impacts of earthquakes?

Answer 7

A: Damage to buildings, fires, tsunamis, landslides, destruction of farmland, water-related diseases, loss of life, and financial losses.

Question 7

Q: What ocean surface temperature is needed for tropical cyclones to form?

Answer 7

A: At least 27°C.

Question 7

Q: What geological feature is associated with a destructive (converging) plate boundary where an oceanic plate is subducted?

Answer 7

A: An ocean trench and potentially a chain of volcanic islands (island arc).

Question 7

Q: What feature forms when two continental plates converge?

Answer 7

A: Fold mountains.

Question 8

Q: What happens at a constructive (divergent) plate boundary involving two continental plates?

Answer 8

A: A rift valley may form.

Question 8

Q: What materials are found in the Earth's mantle?

Answer 8

A: Mainly silicate minerals.

Question 8

Q: What measures can be taken to manage volcanic hazards?

Answer 8

A: Prediction using seismometers, satellites, tiltmeters, and gas monitoring; preparation with hazard maps, lava diversion channels, and building reinforcements.

Question 8

Q: What type of volcano forms at a destructive (converging) plate boundary where oceanic and continental plates interact?

Answer 8

A: An explosive composite volcano.

Question 8

Q: What is the role of seismometers in earthquake prediction?

Answer 8

A: They measure the magnitude of earthquakes.

Question 9

Q: What are some impacts of tropical cyclones?

Answer 9

A: Flooding, loss of life, damage to infrastructure, disruption of services, economic loss, and loss of wildlife habitats.

Question 9

A: Prediction using seismometers, satellites, tiltmeters, and gas monitoring; preparation with hazard maps, lava diversion channels, and building reinforcements.

Answer 9

A: By monitoring rainfall and river discharge, using engineering and soft engineering projects, and adapting infrastructure to mitigate damage.

Question 10

Q: What is sea-floor spreading?

Answer 10

A: The process where new oceanic crust is formed at constructive plate boundaries as magma rises and solidifies.

Question 10

Q: What are tiltmeters used for in volcanic monitoring?

Answer 10

A: They measure subtle changes in the surface of the Earth due to magma accumulation.

Question 10

Q: How does climate change contribute to the severity of droughts?

Answer 10

A: It increases temperatures and can lead to reduced rainfall in affected areas.

Question 10

Q: What is the purpose of a volcano hazard map?

Answer 10

A: To study past eruptions and assess potential future volcanic hazards.

Question 10

Q: What is an island arc?

Answer 10

A: A chain of volcanic islands formed from magma rising through the oceanic crust at a subduction zone.

Question 10

Q: Why is there less volcanic activity when two continental plates converge?

Answer 10

A: Because there is no subduction of oceanic plates.

Question 11

Q: How do satellites help in monitoring volcanic activity?

Answer 11

A: They use heat-seeking cameras to detect increasing ground temperatures.

Question 11

Q: How can lava diversion be managed during an eruption?

Answer 11

A: By constructing lava barriers and channels to redirect the flow.

Question 11

Q: How do embankments help during a tropical cyclone?

Answer 11

A: They protect coastal areas from storm surges.

Question 11

Q: What is the primary method for predicting tropical cyclones?

Answer 11

A: Tracking them using satellites.

Question 11

Q: What factors contribute to flood risk from prolonged rainfall?

Answer 11

A: Soil saturation and rising water tables.

Question 12

Q: What does a hazard zone map indicate in earthquake preparedness?

Answer 12

A: It identifies areas at risk based on geological information and ground stability.

Question 12

Q: How does urbanization contribute to flooding?

Answer 12

A: Concrete and tarmac are impermeable, increasing overland flow.

Question 12

Q: What role does snowmelt play in flooding?

Answer 12

A: Rapid snowmelt can lead to increased overland flow and flooding.

Question 12

Q: What are some protective measures for tropical cyclones?

Answer 12

A: Building cyclone shelters, embankments, and preserving mangrove swamps.

Question 12

Q: What impact does soil saturation have before rainfall events?

Answer 12

A: It reduces infiltration capacity and increases overland flow.

Question 12

Q: How does climate change influence the frequency of droughts?

Answer 12

A: Global warming can decrease rainfall and increase drought conditions.

Question 12

Q: What can be done to manage the impacts of drought?

Answer 12

A: Increase water supplies, conserve water, and improve agricultural practices.

Question 12

Q: How can deforestation affect flood risks?

Answer 12

A: It reduces interception and infiltration, leading to higher overland flow.

Question 12

Q: What is the effect of El Niño on drought conditions?

Question 12

Q: What causes flooding during storm surges?

Answer 12

A: High winds and low pressure associated with cyclones push seawater onto land.

Question 12

Q: How do storm surges contribute to flooding?

Answer 12

A: They cause flooding in low-lying coastal areas during tropical cyclones.

Question 12

Q: What are some impacts of drought on agriculture?

Answer 12

A: Decline in crop yields, loss of crops and livestock, and increased food prices.

Question 12

Q: What is a seismometer used for in the context of earthquakes?

Answer 12

A: To measure the magnitude (strength) of an earthquake.

Question 13

Q: What is one impact of drought on rural areas?

Answer 13

A: Migration from rural to urban areas due to reduced agricultural productivity.

Question 13

Q: What are some physical causes of flooding from heavy rainfall?

Answer 13

A: Increased overland flow and reduced infiltration capacity of the soil.

Question 13

Q: How does urbanization affect flood risk?

Answer 13

A: Increased impervious surfaces like concrete and tarmac lead to higher runoff.

Question 13

Q: What role do geothermal resources play in volcanic regions?

Answer 13

A: They provide opportunities for energy production.

Question 13

Q: What is the role of sediment deposition in flooding?

Answer 13

A: It can lead to changes in river courses and affect land use.

Question 13

Q: What is a primary cause of drought in the context of atmospheric pressure systems?

Answer 13

A: Prolonged high pressure systems that prevent rain formation.

Question 13

Q: How can vegetation affect flood risks?

Answer 13

A: Afforestation helps reduce runoff and improve infiltration.

Question 13

Q: What is the impact of drought on food prices?

Answer 13

A: Food prices increase due to reduced crop yields and supply shortages.

Question 13

Q: What are some ways to prepare for flooding?

Answer 13

A: Using sandbags, pumps, and improving drainage systems.

Question 13

Q: What can be done to prepare for earthquakes?

Answer 13

A: Building earthquake-proof structures, land-use planning, and monitoring seismic activity.

Question 14

Q: What are some economic impacts of tropical cyclones?

Answer 14

A: Loss of production, damage to crops, and reduced export earnings.

Question 14

Q: How can volcanic eruptions create fertile soil?

Answer 14

A: The ash and lava deposits enrich the soil with nutrients.

Question 14

Q: How can tropical cyclones impact infrastructure?

Answer 14

A: They cause damage to buildings, disrupt electricity, transport, and water supplies.

Question 15

Q: What are the effects of landslides triggered by tectonic events?

Answer 15

A: They can cover roads and buildings, disrupting infrastructure.

Question 16

Q: How can floodwaters affect water supplies?

Answer 16

A: They can lead to contamination of drinking water sources.

Question 16

Q: What is the role of afforestation in managing flood risks?

Answer 16

A: It increases interception and infiltration, reducing overland flow.

Question 17

Q: What can be done to mitigate the effects of urbanization on flooding?

Answer 17

A: Implementing sustainable drainage systems and increasing green spaces.

Question 18

Q: What is the role of sediment in flooding events?

Answer 18

A: Sediment deposition can alter river courses and affect floodplain management.

Question 19

Q: How does snowmelt contribute to flooding?

Answer 19

A: Rapid snowmelt can increase river discharge and lead to flooding.

Question 20

Q: What is a common effect of prolonged rainfall on soil?

Answer 20

A: Soil saturation, which reduces infiltration and increases runoff.

Question 21

Q: How can volcanic eruptions impact wildlife habitats?

Answer 21

A: They can destroy habitats through lava flows and ash deposits.

Question 22

Q: How can deforestation affect flood risk?

Answer 22

A: It decreases the land's ability to absorb and retain water, leading to higher runoff.

Question 23

Q: What is the primary cause of flooding from storm surges?

Answer 23

A: Coastal inundation caused by high winds and low pressure from cyclones.

Question 24

Q: What is the effect of urbanization on soil permeability?

Answer 24

A: It decreases soil permeability, leading to increased surface runoff.