Earthquake Basics

EARTHQUAKES

IMPORTANT TERMS

• Seismology:– The study of

earthquakes…seismo means “shake”

• Fault:– A break in the Earth’s

crust – formed from stress

from tectonic forces

• Stress: – Any push or pull on the Earth’s crust– Causes deformation

Plastic Deformation

• Rocks bend like molded clay• Does NOT cause

earthquakes

• Deformation:– The change in the shape of rock in response to

stress

Elastic Deformation• Rock bends until it breaks

• Elastic rebound• Rock snaps back into

original shape• This causes earthquakes

Point inside the earth where an earthquake begins

The point on the Earth’s surface…directly above the focus