•What Are Earthquakes

•10 Interesting Facts About Earthquakes

•10 Interesting Facts cont’d..

•San Andreas Fault Line

•Video Footage During an Earthquake

•Richter Scale

•10 Most Destructive Earthquakes

•1960 Valdivia Earthquake

•Map Showing the Areas Effected By Earthquake

•Video Footage From Valdivia Earthquake

•Divergent Boundary Animation•Thrust Fault Animation

•Homework Assignment

•Thank-You For Your Time

What are Earthquake’s???•An earthquake is the result of a sudden release of

energy in the Earth's crust that creates seismic waves. Earthquakes are recorded with a

seismometer, also known as a seismograph. The moment magnitude of an earthquake is

conventionally reported, or the related and mostly obsolete Richter magnitude, with magnitude 3 or

lower: are earthquakes being barely felt and magnitude 7 causing serious damage over large areas. Intensity of shaking is measured on the

modified Mercalli scale.•At the Earth's surface, earthquakes manifest

themselves by shaking and sometimes displacing the ground. When a large earthquake epicenter is located offshore, the seabed sometimes suffers sufficient displacement to cause a tsunami. The

shaking in earthquakes can also trigger landslides and occasionally volcanic activity.

10 Interesting Facts About Earthquake’s

1. The largest recorded earthquake in the United States was a magnitude 9.2 that struck Prince William Sound, Alaska on

Good Friday, March 28, 1964 UTC.

2.The largest recorded earthquake in the world was a magnitude 9.5 (Mw) in Chile on May 22, 1960

3.Although both are sea waves, a tsunami and a tidal wave are two different unrelated phenomenon. A tidal wave is a

shallow water wave caused by the gravitational interactions between the Sun, Moon, and Earth. A tsunami is a sea wave caused by an underwater earthquake or landslide (usually triggered by an earthquake) displacing the ocean water.

4.The hypocenter of an earthquake is the location beneath the earth's surface where the rupture of the fault begins. The

epicenter of an earthquake is the location directly above the hypocenter on the surface of the earth.

5.It is estimated that there are 500,000 detectable earthquand akes in the world each year. 100,000 of those can be felt, 100 of

them cause damage.

10 Interesting Facts Cont’d….6. The magnitude of an earthquake is a measured value of the earthquake size. The magnitude is

the same no matter where you are, or how strong or weak the shaking was in various locations.

The intensity of an earthquake is a measure of the shaking created by the earthquake, and this value does vary with location.

7. Each year the southern California area has about 10,000 earthquakes. Most of them are so small that they are not felt. Only several hundred are greater than magnitude 3.0, and only

about 15-20 are greater than magnitude 4.0.

8. From 1975-1995 there were only four states that did not have any earthquakes. They were: Florida, Iowa, North Dakota, and Wisconsin.

9. The world's deadliest recorded earthquake occurred in 1556 in central China. It struck a region where most people lived in caves carved from soft rock. These dwellings collapsed

during the earthquake, killing an estimated 830,000 people. In 1976 another deadly earthquake struck in Tangshan, China, where more than 250,000 people were killed

10. *The average rate of motion across the San Andreas Fault Zone during the past 3 million years is 56 mm/yr (2 in/yr). This is about the same rate at which your fingernails grow.

Assuming this rate continues, scientists project that Los Angeles and San Francisco will be adjacent to one another in approximately 15 million years.*

San Andreas Fault Line

The San Andreas Fault is the sliding boundary between the Pacific Plate and the North American Plate. It slices California in two from Cape Mendocino to the Mexican

border. San Diego, Los Angeles and Big Sur are on the Pacific Plate. San Francisco,

Sacramento and the Sierra Nevada are on the North American Plate

http://geology.com/articles/images/san-andreas-fault-map.jpg

Video Footage During an Earthquake

• http://www.youtube.com/watch?v=4Y-62Ti5_6s

Richter Scale

•Developed in 1935 by Charles Richter in partnership with Beno Gutenberg, both of the California Institute of Technology, the scale was intended to be used only in a particular study area in California, and on seismograms recorded on a particular instrument, the Wood-Anderson

torsion seismometer •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.

Charles Richter

10 Most Destructive EarthquakesLocation 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 9.0

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 8.7

India-China border Aug. 15, 1950 8.6

Kamchatka Feb. 3, 1923 8.5

1960 Valdivia earthquake

• The 1960 Valdivia earthquake or Great Chilean Earthquake of May 22 1960 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 3000-5700 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

Footage From Valdivia Earthquake

http://www.youtube.com/watch?v=vxXf-dYtG7Q&feature=related

Map Showing the Areas Affected by the Tsunami

Divergent Boundary Animation

:Animation

A divergent boundary is where two adjacent tectonic plates are moving away from each other.

Thrust Fault Animation

• Thrust Fault

A thrust fault is a reverse fault with a dip of 45° or less.

Homework Assignment

• Go through magazines/newspapers and make a collage of different pictures of earthquakes.

• Due Next Week 11-22-08

Thank You For Your Time

• Hope your love for earthquakes has grown.

Jeff Fillman and Biz Van Tiflin