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)
CHAPTER 8: EARTHQUAKES and EARTH’S INTERIOR
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)
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.
Western side of fault moved 4.7 meters to the north.
1906 San Francisco Earthquake
Over 225,000 people were homeless.
Over 3000 people died.
The San Andreas Fault, CA
Based on the movements of the San Andreas fault the Elastic Rebound hypothesis was developed.
Forces deform and put pressure on rocks.
The pressure overcomes the strength of the rocks. The rocks break and slip.
The pressure is relieved and the ground stops moving.
Pg.. 220 Figure 4
Elastic Rebound Hypothesis
UNCONFORMITY ????? http://www.classzone.com/books/earth_science/terc/content/visualizations/es2902/es2902page01.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