earthquake overview and earthquake engineering activity

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Earthquake overview and Earthquake Engineering activity. What is an Earthquake?. Pattern of earthquakes defines the boundaries of tectonic plates There are about 23 major plates. - PowerPoint PPT Presentation


  • Earthquake overview and Earthquake Engineering activity

  • What is an Earthquake?

  • Pattern of earthquakes defines the boundaries of tectonic platesThere are about 23 major plates

  • Three types of interactions between plates as they move around:

    Sliding past one another - transform boundaryRunning into one another - convergent boundaryMoving away from one another - divergent boundary

  • Where are earthquakes likely to occur?Tectonic development of the New Madrid rift complex, Mississippi embayment, North America:A rift was splitting apart the North American continent 600 million years agoRifting stoppedThe continent has been under compression for at least 150 million yearsThe ancient faults may have been reactivated but are moving in the opposite senseby Lawrence W. Braile, William J. Hinze, G. Randy Keller, Edward G. Lidiak, and John L. Sexton; 1986; in Tectonophysics, Volume 131 (1986).

  • Three types of faultsFormation depends on the type of plate motion and complex reaction of earths lithospheric blocks


  • How strong will the ground shake? Geological Survey Fact Sheet-168-95 1995

  • What determines the level of shaking?MagnitudeMore energy releasedDistanceShaking decays with distanceLocal soilsamplify the shaking

  • P and S Waves

  • It is estimated that there are 500,000 detectable earthquakes in the world each year. 100,000 of those can be felt, and 100 of them cause damage.

  • 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.

  • Richter magnitude scaleBecause of the logarithmic basis of the scale, each whole number increase in magnitude represents a tenfold increase in measured amplitude; as an estimate of energy, each whole number step in the magnitude scale corresponds to the release of about 31 times more energy than the amount associated with the preceding whole number value.

  • from:

  • Taken from:

  • The 1906 San Francisco Earthquake (M~7.8) ~3 m right lateral offset on the San Andreas fault

  • The 1906 San Francisco Earthquake (M~7.8) San Francisco after the Earthquake and fire.

  • The 1906 San Francisco Earthquake (M~7.8) Comparison of fault lengths for selected significant events on the San Andreas.

  • Soft first story failure

  • Building shifted off foundation

  • Olive View Hospital, 1971 San Fernando Earthquake

  • Olive View Hospital, 1971 San Fernando Earthquake

  • Dec. 26, 2003M6.6 Earthquake,Bam, Iran,~80% of buildingsdestroyed

  • Earthquake Engineering Activity:Supplies: (per group)1 sheet of card stock (cut into 1 wide 8 long strips)1 3x5 note card1 meter of tape1 tray1 golf ballRuler

  • Earthquake Engineering Activity:Rules:Must use only the materials providedStructure must be 15 cm in height (the bottom of the ball must be 15 cm off the tray)Structure must hold the golf ball (the ball cannot be taped down)


  • MagnitudeEarthquake EffectsEstimated Number Each Year2.5 or lessUsually not felt, but can be recorded by seismograph.900,0002.5 to 5.4Often felt, but only causes minor damage.30,0005.5 to 6.0Slight damage to buildings and other structures.5006.1 to 6.9May cause a lot of damage in very populated areas.1007.0 to 7.9Major earthquake. Serious damage.208.0 or greaterGreat earthquake. Can totally destroy communities near the epicenter.One every 5 to 10 years

    * G. Hildenbrand,Victoria E. Langenheim, Eugene Schweig, Peter H. Stauffer, and James W. Hendley II Uncovering Hidden Hazards in the Mississippi Valley U.S. Geological Survey Fact Sheet 200-96 1996

    *Significantly different attenuation from west coast Schweig, Joan Gomberg, and James W. Hendley II U.S. Geological Survey (901) 678-2007 Center for Earthquake Research and Information The University of Memphis, Memphis, TN 38152 U.S. Geological Survey Fact Sheet-168-95 1995

    References:The Severity of an Earthquake, a U. S. Geological Survey General Interest Publication



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