Natural Hazards and Earth Structure

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Questions and Answers

At which type of plate boundary would you expect to find a deep ocean trench?

Destructive (correct)

Conservative

Transform

Constructive

Which of the following is NOT a factor that influences the risk posed by natural hazards?

Geographic location of the hazard

Population density

Distance from the equator (correct)

Wealth of the country

Climate change

What is the primary force driving the movement of tectonic plates?

Convection currents (correct)

Tidal forces

Gravity

Wind

Which type of plate boundary is associated with the formation of new crust?

Constructive (D) Signup and view all the answers

What is the main process that leads to volcanic eruptions at destructive plate margins?

Melting of the oceanic plate (B) Signup and view all the answers

Which of the following examples is a result of a conservative plate margin?

The San Andreas Fault (D) Signup and view all the answers

Which of the following natural hazards is most likely to be caused by the movement of tectonic plates?

Earthquake (D) Signup and view all the answers

Which of the following statements about plate tectonics is TRUE?

Tectonic plates are made up of the Earth's crust and upper mantle. (B) Signup and view all the answers

What are the main causes of earthquakes that are not related to plate margins?

Mining and oil extraction (A), Fracking (B) Signup and view all the answers

What is the primary reason for the vulnerability of the Kaikoura, New Zealand region to earthquakes?

The region is located near a tectonic plate boundary, where two plates interact. (A) Signup and view all the answers

In terms of impact, which of the following was a significant secondary effect of the 2016 Kaikoura earthquake?

Triggering of landslides that disrupted transportation infrastructure (B) Signup and view all the answers

Which of the following is a long-term response to the 2015 Nepal earthquake?

Financing of projects to build earthquake-resistant housing (A) Signup and view all the answers

What factor contributed to the limited effectiveness of rescue efforts in the immediate aftermath of the 2015 Nepal earthquake?

Lack of proper equipment and machinery (B) Signup and view all the answers

What factor explains why many people continue to live near volcanoes?

Volcanic soils are fertile, suitable for agriculture. (B), The beauty of volcanic landscapes attracts tourists. (C) Signup and view all the answers

Which of the following is a factor that does not significantly affect the decision of individuals to live near volcanoes?

The presence of geothermal energy resources (B) Signup and view all the answers

What is the primary reason people in wealthier nations may choose to live in areas with earthquake risks?

Efforts by governments to minimize risks through monitoring and planning. (C) Signup and view all the answers

What feature distinguishes the Kaikoura earthquake from the 2015 Nepal earthquake in terms of the plate boundary type?

The Kaikoura earthquake involved both subducting and sliding plate interactions. (C) Signup and view all the answers

What is the primary benefit of volcanic ash to soil fertility?

It contains essential minerals like potassium and phosphorus. (A) Signup and view all the answers

Which of the following statements is true in relation to the relationship between earthquakes and volcanoes?

Both earthquakes and volcanoes can occur at plate boundaries. (D) Signup and view all the answers

Which of the following countries is located on the Pacific 'Ring of Fire'?

Japan (A) Signup and view all the answers

Which of the following actions was not a feature of the immediate response to the Kaikoura earthquake?

Issuing long-term financial aid packages for reconstruction. (D) Signup and view all the answers

What was a significant barrier to aid distribution and rescue operations in the immediate aftermath of the 2015 Nepal earthquake?

Limited access to roads and bridges due to damage from the earthquake. (D) Signup and view all the answers

Why is the 'Ring of Fire' an area of high volcanic and earthquake activity?

It encompasses a significant number of convergent plate boundaries, where plates collide. (C) Signup and view all the answers

Study Notes

Natural Hazards

Natural hazards occur when natural forces (e.g., tectonic activity, weather) cause harm to humans.
Examples include: tsunamis, droughts, supervolcano eruptions, avalanches, blizzards, forest fires, sinkholes, mudslides, flash floods, tropical storms, volcanoes, and earthquakes.

Factors Affecting Hazard Risk

Wealth: A country's wealth impacts its ability to prepare for and cope with hazards.
Population Density: High population density areas are more vulnerable to hazard impacts.

Earth Structure and Plate Tectonics

Earth's crust is divided into tectonic plates, which are constantly moving.
Plate boundaries (margins) are locations where earthquakes, volcanoes, mountains, and ocean trenches form.
About 8 major plates and many smaller ones exist.
Plate movement is largely driven by convection currents in the Earth's mantle.

Types of Plate Margins

Destructive Margin: An oceanic plate subducts beneath a continental plate, causing earthquakes, volcanoes, and forming trenches and fold mountains. (e.g., Nazca and South American plates)
Conservative Margin: Two plates slide past each other, resulting in powerful earthquakes. (e.g., San Andreas Fault)
Constructive Margin: Two plates move apart, creating a gap filled by magma, leading to volcanic eruptions and gentle earthquakes. (e.g., mid-Atlantic ridge)

Earthquake Locations

Earthquakes are commonly found in bands aligning with plate margins (e.g., Pacific Ring of Fire, mid-Atlantic).
Some earthquakes occur away from plate boundaries, potentially due to human activities (e.g., fracking).

Volcano Locations

Volcanoes are often located along plate margins.
A significant belt encircles the Pacific Ocean (Pacific Ring of Fire), and another exists along the mid-Atlantic ridge.

Case Study: 2016 New Zealand Earthquake (Kaikoura)

Magnitude: 7.8
Primary Effects: 2 fatalities, injuries, damaged/destroyed homes, economic losses, and infrastructure damage.
Secondary Effects: Landslides, flooding, tsunami.
Immediate Responses: Tsunami warning, emergency housing, power and water restoration. International aid.
Long-Term Responses: Funding for reconstruction, road and rail repair, community support initiatives, and earthquake-resistant infrastructure development.

Case Study: 2015 Nepal Earthquake

Magnitude: 7.8
Primary Effects: Thousands of deaths and injuries, numerous damaged/destroyed buildings widespread homelessness, significant economic loss, and water/sanitation issues.
Immediate Responses: International aid, rescue efforts, emergency support by NGOs and aid organisations.
Long-Term Responses: Relief efforts for recovering from destroyed building, World Bank financed reconstruction projects to build earthquake resistant housing, and improve infrastructure.

Reasons for Living Near Hazards

Limited alternatives/affordability: Moving away might not be an option
Familiarity: The people and places are well known.
Effective monitoring/governance: Risk is minimized through preparedness and responses.
Economic activity: Opportunities for tourism and agriculture.
Fertile soil: Volcanic activity results in high-quality soil for crops.

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Description

Explore the critical concepts of natural hazards, their impacts, and the factors affecting risk. Learn about Earth's structure, plate tectonics, and the types of plate margins. This quiz will test your understanding of how natural forces shape our environment and affect human populations.