Earthquake Theory Flashcard

Front

What is the elastic rebound theory?

Back

The elastic rebound theory explains that earthquakes occur when stress builds up in rocks until they break, releasing energy in the form of seismic waves. It was first proposed by Reid following the 1906 San Francisco earthquake.

Front

What characterizes tsunamis?

Back

Tsunamis have relatively small amplitudes compared to their very long wavelengths, allowing them to travel across oceans with little loss of energy.

Front

What is the source of an earthquake called?

Back

The source of an earthquake is referred to as the focus.

Front

What is the average composition of the continental crust?

Back

The average composition of the continental crust most closely approximates that of granite.

Front

Which statement about the crust is NOT true?

Back

Oceanic crust is enriched in potassium, sodium, and silicon.

Front

What are seismic waves?

Back

Seismic waves are waves of energy that travel through the Earth, generated by the sudden breaking of rock in an earthquake.

Front

What is the difference between oceanic and continental crust?

Back

Oceanic crust is thinner and denser than continental crust, which is thicker and less dense.

Front

What is a fault in geology?

Back

A fault is a fracture or zone of fractures between two blocks of rock, allowing for movement and displacement.

Front

What is the Richter scale?

Back

The Richter scale is a logarithmic scale used to measure the magnitude of earthquakes based on the amplitude of seismic waves.

Front

What is a seismic focus?

Back

The seismic focus is the point within the Earth where an earthquake originates.