STRESS – The amount of force exerted on a material.

3 TYPES

COMPRESSION

TENSION

SHEAR

COMPRESSION

TENSION

SHEAR

STRAIN – When materials become deformed in response to stress.

STRAIN

FAILURE – When stress exceeds the strength of the material.

FAILURE

FAULT – A failure of Earth’s crust.

3 TYPES

NORMAL

REVERSE

STRIKE-SLIP

NORMAL

REVERSE

STRIKE-SLIP

FOCUS – The point where FAILURE occurs below Earth’s surface: where an earthquake originates.

EPICENTER – The point on Earth’s surface directly above the FOCUS.

Seismic Waves

THREE TYPESPRIMARY

SECONDARY

SURFACE

http://www.geo.mtu.edu/UPSeis/waves.html

SEISMOMETER – An instrument that measures the vibrations caused by earthquakes

SEISMOGRAPH

MAGNITUDE – The amount of energy released during an earthquake.

RICHTER SCALE – A numeric scale that classifies earthquakes based on the size of its seismic waves.

Earthquake measuring 7.0 kills 46 in Indonesia and leaves thousands homeless…

TSUNAMI – A large ocean wave generated by vertical motions of the sea floor during an earthquake.