1. Earthquakes!
Earthquakes!

2. What are Earthquake’s???
Earthquake = a sudden and violent shaking of the ground as a result of movements within the earth's crust or volcanic action

3. Stress = the total force acting on crustal rocks per unit of area
-when stress overcomes the strength of the rocks involved,
movement occurs along fractures in the rock (earthquakes)
Strain = the deformation of materials in response
to stress
Epicenter = point on the earth's surface vertically above the focus of an earthquake
Earthquake epicenter offshore or underwater, it can cause a massive tidal wave (tsunami).
-Earthquakes can also cause/trigger landslides and/or volcanic activity

4. Three kind of stress:
Compression = the maximum compressive stress that can be applied to a material before failure occurs
Tension = a stress which stretches rocks in two opposite directions
Shear = where the stress is parallel to the surface of the material

5. Hanging Wall = The block positioned over the fault
Footwall = the block positioned below the fault

6. Types of Faults
Compression causes horizontal and vertical movement
Tension causes horizontal and vertical movement
Shear causes horizontal movement

7. Types of Seismic Waves Squeeze and push rocks in the
Seismic wave animation
Squeeze and push rocks in the
direction along which the waves
are traveling. BODY WAVE
Slower than P-waves. Similar to
the movement of a jump rope that is
jerked up and down at one end.
BODY WAVE
Slowest. Only travel along Earth’s
surface. Cause the most destruction

8. Richter Scale -Numerical rating system that measures
the energy of the largest seismic waves
Developed in 1935 by Charles Richter in partnership with Beno Gutenberg, both of the California Institute of Technology.
Charles Richter
The Richter magnitude scale, assigns a single number to quantify the amount of seismic energy released by an earthquake. It is a base-10 logarithmic scale obtained by calculating the logarithm of the combined horizontal amplitude of the largest displacement from zero on a Wood–Anderson torsion seismometer output. So, for example, an earthquake that measures 5.0 on the Richter scale has a shaking amplitude 10 times larger than one that measures 4.0. The effective limit of measurement for local magnitude is about ML = 6.8.

9. Other scales used
Moment magnitude scale – a rating scale that measures the energy
released by an earthquake. Takes into account the size of the
fault rupture, amount of movement along the fault, and the rocks’
stiffness
Modified Mercalli scale – rates the types of damage and other effects
of an earthquake. Uses Roman numerals, goes from I - XII

10. 10 Most Destructive Earthquakes
Location
Date
Magnitude
Chile
May 22, 1960
9.5
Prince William Sound, Alaska
March 28, 1964
9.2
Andréa of Islands, Aleutian Islands
March 9, 1957
9.1
Kamchatka
Nov. 4, 1952
9.0
Off western coast of Sumatra, Indonesia
Dec. 26, 2004
Off the coast of Ecuador
Jan. 31, 1906
8.8
Rat Islands, Aleutian Islands
Feb. 4, 1965
8.7
Northern Sumatra, Indonesia
March 28, 2005
India-China border
Aug. 15, 1950
8.6
Feb. 3, 1923
8.5

11. 1960 Valdivia earthquake Tsunami Animation News Coverage
The 1960 Valdivia earthquake or Great Chilean Earthquake of May is the most powerful earthquake ever recorded, rating 9.5 on the moment magnitude scale. It occurred in the afternoon around 2:11 pm local time and its resulting tsunami affected southern Chile, Hawaii, Japan, the Philippines, eastern New Zealand, south east Australia and the Aleutian Islands in Alaska.
The epicenter was near Canete about 435 miles south of Santiago although Valdivia, Chile was the most affected city. It caused tsunamis that severely battered the Chilean coast, with waves up to 82 feet. The main tsunami raced across the Pacific Ocean and devastated Hilo, Hawaii. Waves as high as 35 feet were recorded 6,000 miles from the epicenter, and as far away as Japan and the Philippines. The death toll and monetary losses arising from such a widespread disaster can never be precisely known. Various estimates of the total number of fatalities from the earthquake and tsunamis have been published, with the USGS citing studies with figures of killed, and another source uses an estimate of 6000 dead. Different sources have estimated the monetary cost ranged from 400 million to 800 million US dollars. In 2005 terms adjusted for inflation about 2.6 to 5.2 billion
Tsunami Animation
News Coverage

12. Map Showing the Areas Affected by the Tsunami

13. Video Footage During an Earthquake