Detailed Notes - Tectonics - Edexcel Geography A-level

What is a natural hazard?

A natural hazard is a potential threat to human life and property, which can be either hydro-meteorological or geophysical.

What are geophysical hazards?

Geophysical hazards occur near plate boundaries and can cause events like collisions, earthquakes, and volcanic activity.

What happens during an intra-plate earthquake?

Intra-plate earthquakes occur near the middle of plates due to pre-existing weaknesses being reactivated.

What are volcanic hotspots?

Volcanic hotspots are localized areas with unusually high temperatures in the lithosphere, caused by the upwelling of hot molten material from the Earth's core.

What is the Ring of Fire?

The Ring of Fire is an area in the Pacific Ocean basin known for its high volcanic and earthquake activity, located along tectonic plate boundaries.

What trends have been observed in tectonic hazards since 1960?

The total number of recorded hazards has increased, fatalities have decreased overall, and more people are being affected due to population growth.

What is Degg's Model?

Degg's Model illustrates that a disaster will only occur when a vulnerable population is exposed to a natural hazard.

What are the four sections of the Earth's structure?

The Earth consists of the crust, mantle, outer core, and inner core.

What characterizes destructive plate boundaries?

Destructive plate boundaries involve the denser oceanic plate subducting beneath a continental plate, leading to ocean trenches and volcanic activity.

What is seafloor spreading?

Seafloor spreading is the process where magma rises and cools at constructive plate boundaries, forming new oceanic crust.

What are secondary hazards of earthquakes?

Secondary hazards include soil liquefaction, landslides, and tsunamis.

How does a tsunami form during an earthquake?

A tsunami is generated when an oceanic crust is jolted, displacing the water above it, which then propagates as a wave.

What are the characteristics of a volcanic eruption?

Primary hazards include lava flows, pyroclastic flows, tephra and ash flows, and volcanic gases.

What is the Volcanic Explosivity Index (VEI)?

The VEI measures the explosiveness of a volcanic eruption based on the height of ejected materials and duration.

What does the Moment Magnitude Scale measure?

The Moment Magnitude Scale measures the total energy released by an earthquake.

What are the three approaches to managing tectonic hazards?

The three approaches are: Modify the Event, Modify the Vulnerability, and Modify the Loss.

What is the purpose of land use zoning?

Land use zoning aims to prevent building on low-lying or high-risk areas to reduce vulnerability to hazards.

What factors can increase a population's vulnerability to a hazard?

Factors include unstable governance, high population density, geographic isolation, and lack of preparedness.

What is the Park Model in hazard response?

The Park Model represents human responses to hazards, illustrating recovery stages such as relief, rehabilitation, and reconstruction.

What role do NGOs play in disaster management?

NGOs provide essential services such as funding, coordination of rescue efforts, and development of reconstruction plans following disasters.