Transcript Slide 1

CHAPTER 8: EARTHQUAKES
and EARTH’S INTERIOR
ROOTS:
Crypto = hidden (cryptography)
Cumul = mass (cumulative)
Cycl = circle (cycle)
De = reduce (decelerate)
Deca = ten (decade)
Deci = one tenth (decibel)
Dem = people (democracy)
Demi = less than (demigod)
Dendr = tree (dendriform – treelike)
Dent = tooth (dentist)
California Earthquake!
Terrashake!
http://visservices.sdsc.edu/projects/scec/teras
hake/2.1/
CH 8.1 What is an Earthquake?
Earthquake = the vibration of Earth produced by the rapid
release of energy.
Focus = point inside
Earth where the
earthquake starts.
Epicenter = location
on the surface
directly above the
focus.
Epicenter and Focus
http://www.pbs.org/wnet/savageearth/animations/earthquakes/index.html
Fault = fracture in Earth’s crust where movement has
occurred.
1906 San Francisco Earthquake
Western side of fault
moved 4.7 meters to the
north.
Over
people
were homeless.
Over 225,000
3000 people
died.
The San Andreas Fault, CA
Based on the movements of the San Andreas fault the
Elastic Rebound hypothesis was developed.
A. Existing Fault
B. Forces deform
and put pressure
on rocks.
C. The pressure
overcomes the
strength of the
rocks. The rocks
break and slip.
D. The pressure is
relieved and the
ground stops
moving.
Pg.. 220 Figure 4
Elastic Rebound Hypothesis
http://www.sceyencestudios.com/animation.htm
UNCONFORMITY ?????
http://www.classzone.com/books/earth_scien
ce/terc/content/visualizations/es2902/es2902
page01.cfm?chapter_no=visualization
Most earthquakes are
produced by the rapid
release of elastic
energy stored in rock
that has been
subjected to great
forces. When the
pressure on the rock
exceeds the strength
of the rock, the rock
suddenly breaks.
Aftershocks and Foreshocks
Foreshocks = small earthquakes that occur prior to a
larger earthquake.
Aftershocks = small earthquakes that occur following
a larger earthquake.
Foreshocks and Aftershocks
http://earthquake.usgs.gov/learning/animations/animation.php?flash_title=Foreshocks
+Flash+Animation&flash_file=aftershock&flash_width=400&flash_height=275