I. Fault: A crack in the Earth’s crust, where rock rubs against rock.

A. San Andreas Fault

C.

D. Dead Sea Fault

II. Seismograph: Instrument used to record seismic waves

• ‘Seismic’ From seismos, shaking Related to, or caused by an earthquake

of other vibration of the Earth.

‘Tectonic’

From tekton, builder relating to, or caused by large-scale

movements of the Earth’s crust

http://tinyurl.com/8xpgdq

III. Richter Scale

Measures the amount of energy in an earthquake

A. 1.0-3.0: Felt only by a few persons, especially on upper floors of

buildings.

B. 3.0-6.0: Felt by all, many frightened. Some heavy furniture moved; a few instances of fallen plaster.

Damage slight.

C. 7.0+: Damage great in substantial buildings, with partial collapse. Buildings

shifted off foundations.

D. Arkansas is at risk of a major earthquake!

IV. Focus and Epicenter

A. An earthquake's focus the position where the energy stored in the strain of the crust is released.

B. 1. The epicenter is the point on the surface that is directly above the focus

2. The epicenter is usually the location of greatest damage.

V. S, P, and Surface Waves

http://www.kettering.edu/~drussell/Demos/waves/wavemotion.html

A. P Waves Compression (‘scrunching’) waves. Fastest of all waves (15,000 mph) First to arrive Travel in liquids, solids, and gases Usually smallest damage

B. S Waves Up and down waves Medium speed (7000 mph) Arrive after P waves Do not travel through liquid—so they

are stopped in the outer core

C. Surface Waves

Rolling waves Travel only on surface Slowest (4500 mph) So most damage

http://neic.usgs.gov/neis/eq_depot/2002/eq_021103/ak_seismic_waves.html