Earthquakes Lecture Practice Geography

This set of 30 vocabulary flashcards covers key terminology and concepts related to earthquakes, magnitude scales, and tectonic plate boundaries as presented in the lecture notes.

Earthquake

An intense shaking of Earth’s surface caused by movements in Earth’s outermost layer.

Magnitude

A measure of the strength of an earthquake, typically calculated using the height of seismic waves.

Richter scale

A logarithmic scale used to measure the strength of an earthquake where each whole number increase represents a $10$ times increase in amplitude.

Seismograph/seismometer

An instrument that detects seismic waves from an earthquake to help calculate its magnitude.

Epicentre

The point on the Earth's surface directly above the focus of an earthquake.

Focus (Hypocentre)

The point within the Earth where sudden movement along a fault originates, causing an earthquake.

Constructive (divergent) plate boundary

A boundary where tectonic plates move apart, allowing magma to rise and create new crust.

Destructive (convergent) plate boundary

A boundary where plates move towards each other and old crust is destroyed or goes back into the mantle.

Conservative (transform) plate boundary

A boundary where plates slide past each other, causing earthquakes due to friction without creating or destroying crust.

Faults

Breaks or slips in the rocks within the Earth's layer where sudden movement causes earthquakes.

Logarithmic scale

A mathematical scale used by the Richter scale where each whole number increase represents about $31.6$ times more energy released.

Seismic waves

Waves of energy that travel through the Earth as a result of an earthquake.

Micro earthquake

An earthquake with a magnitude less than $2.0$ that is usually not felt by people.

Minor earthquake

An earthquake with a magnitude of $2.0 - 3.9$ that is often felt but rarely causes damage.

Light earthquake

An earthquake with a magnitude of $4.0 - 5.9$ where dishes rattle and windows shake.

Strong earthquake

An earthquake with a magnitude of $6.0 - 6.9$ that can cause wall cracks and damage to some buildings.

Major earthquake

An earthquake with a magnitude of $7.0 - 7.9$ that causes heavy damage to buildings, bridges, and roads.

Great earthquake

An earthquake with a magnitude of $8.0$ and above causing very heavy damage, ground cracks, and landslides.

Shallow-focus earthquakes

Earthquakes that occur close to the Earth's surface.

Deep-focus earthquakes

Earthquakes that originate deep within the Earth's outermost layer or mantle.

Mid-Atlantic Ridge

A real-world example of a constructive (divergent) plate boundary.

Andes Mountains

A real-world example of a destructive (convergent) plate boundary.

San Andreas Fault

A real-world example of a conservative (transform) plate boundary located in California.

Tectonic plates

Large segments of the Earth's outer layer that are constantly moving and interacting at their boundaries.

Magma

Molten rock that rises from below the Earth's surface to fill gaps at constructive boundaries or cause volcanoes at destructive boundaries.

New crust

The material formed at constructive boundaries when magma rises to fill the gap between plates moving apart.

Amplitude

The height of seismic waves used by scientists to calculate the magnitude on the Richter scale.

Friction

The force that builds up as plates slide past each other at conservative boundaries, eventually causing earthquakes.

Iceland

A geographical location cited as an example of where a constructive plate boundary occurs.

Japan

A geographical location cited as an example of where a destructive plate boundary occurs.