a large, rigid slab of Earth's lithosphere (outer layer) that sits on the semi-solid asthenosphere beneath it

a semi-solid layer of Earth's upper mantle

the transfer of heat through the movement of fluids: warmer, less dense material rises and cooler, denser material sinks, creating a circular flow

Plate tectonics theory

Geography

An introduction to natural hazards

Factors affecting hazard risk

Global distribution of earthquakes and volcanoes

Processes at constructive/divergent plate margins

Processes at destructive/convergent plate margins

Processes at conservative plate margins

Primary and secondary effects and responses to tectonic hazards

An example of effects and responses to a tectonic hazard in an HIC

An example of effects and responses to a tectonic hazard in an LIC

Reducing risks from earthquakes and volcanoes

Using GIS to visualise physical processes at different types of plate margin

This unit teaches pupils about natural and tectonic hazards, their location, causes and effects. Pupils learn about the different types of hazard before focusing on earthquakes and volcanoes. Pupils will learn about tectonic processes, hazard impacts and the options for mitigation and adaptation.

Natural and tectonic hazards

Order the layers of Earth, starting from the surface.

According to plate tectonic theory, the lithosphere is divided into a number of {{}} plates. These plates sit on top of a semi-solid layer of the upper mantle called the asthenosphere.

the crust and most solid part of the mantle

semi-solid and ductile: bends, flows and stretches under stress

mostly made of crust: oceanic and continental crust

lower density as solid rocks are not compressed as much

What are characteristics of the asthenosphere?

Heat rises: hot material from the lower mantle rises up towards the lithosphere.

When the material cools, it sinks back down again.

This rising and falling creates circular convection currents.

The currents drag on the base of tectonic plates, which moves them.

Put the convection current theory in the correct order.

In 1912, Alfred Wegener published a theory that the continents had once been joined together and had since moved apart. This theory was known as {{}} drift.

A {{}} is a natural event that has the potential to cause damage, loss of life or economic disruption.

Order the layers of Earth, starting from the outside and going towards its centre.

molten/semi-molten rock beneath Earth's surface

molten or partially molten rock that has been ejected by volcanoes

Which of the following are geological hazards?

Hazard {{}} is the probability that a natural hazard will affect a population.

The {{}} is the outer layer of Earth. It is a thin layer between 0 - 60 km thick upon which we live.

Plate tectonics theory

Lesson outcome