EARTHQUAKESEARTHQUAKES

Presented by Presented by Georgios PatrinosGeorgios Patrinos

OUTLINEOUTLINE Introduction Introduction

Causes of earthquakesCauses of earthquakes

Description of initial earthquake developmentDescription of initial earthquake development

Analysis of seismic wavesAnalysis of seismic waves

Magnitude of an earthquakeMagnitude of an earthquake

Interview with people that survived the catastrophic Interview with people that survived the catastrophic effects of big earthquakeseffects of big earthquakes

RecommendationsRecommendations

ConclusionsConclusions

INTRODUCTIONINTRODUCTION No natural phenomenon creates No natural phenomenon creates

more fear and insecurity than an more fear and insecurity than an earthquakeearthquake ..

Every day thousands of earthquakes Every day thousands of earthquakes occuroccur ..

Researchers (Charles Richter, Lord Researchers (Charles Richter, Lord Rayleigh) have investigated the Rayleigh) have investigated the nature of earthquakes nature of earthquakes

Causes of earthquakes The earth is surrounded by The earth is surrounded by

a hard layer of rocks.a hard layer of rocks. This layer, which has an This layer, which has an

average width of 80 km average width of 80 km (and includes a part of the (and includes a part of the upper mantle), is called upper mantle), is called the Lithosphere.the Lithosphere.

Lithosphere separated into Lithosphere separated into different parts which are different parts which are called lithospheric plates.called lithospheric plates.

Under the lithosphere the Under the lithosphere the material is semi liquid and material is semi liquid and forms a layer called the forms a layer called the asthenosphere.asthenosphere.

Causes of earthquakes

Divergent plate Divergent plate boundaries boundaries

Convergent plate Convergent plate boundaries boundaries

Transcurrent plate Transcurrent plate boundariesboundaries

Description of initial earthquake development

When the stresses When the stresses become too great become too great so as to overcome so as to overcome the strength of the the strength of the lithosphere lithosphere material in this material in this area, the rock area, the rock breaks and a breaks and a seismic fault is seismic fault is created.created.

Description of initial earthquake development

Focus of the Focus of the earthquake.earthquake.

Epicenter.Epicenter. Focus depth Focus depth

Analysis of seismic waves

Primary waves (P)Primary waves (P)

Less catastrophic Less catastrophic

Transfer relatively small Transfer relatively small amount of energyamount of energy

secondary wavessecondary waves (S) (S)

The most dangerousThe most dangerous Transfer great amounts Transfer great amounts

of energy of energy

Analysis of seismic waves

Rayleigh wavesRayleigh waves

Love wavesLove waves

Magnitude of an earthquakeMagnitude of an earthquake

MagnitudMagnitudee

DamageDamage

44 Widely felt and is strong enough to crack plaster.Widely felt and is strong enough to crack plaster.

55 A strong vibration shakes the earth, damaging A strong vibration shakes the earth, damaging chimneys and weak buildings.chimneys and weak buildings.

66 Strong enough to badly damage average buildingsStrong enough to badly damage average buildings

77 This earthquake is strong enough to destroy even This earthquake is strong enough to destroy even well-built structureswell-built structures

88 Even special, earthquake-resistant buildings will be Even special, earthquake-resistant buildings will be badly damaged.badly damaged.

99 Widespread destructionWidespread destruction

RecommendationsRecommendations

In view of the above the following In view of the above the following recommendations are outlinedrecommendations are outlined ::

Improvements on antiseismic legislation Improvements on antiseismic legislation and technologyand technology ..

Study of the seismic activity and the Study of the seismic activity and the terrain of the area are obligatoryterrain of the area are obligatory

Education and action plans to minimise Education and action plans to minimise the risk of an earthquake’s aftermath.the risk of an earthquake’s aftermath.

Evacuation plans , emergency exercises .Evacuation plans , emergency exercises .

BibliographyBibliography

Bolt, B.A. (1993) Bolt, B.A. (1993) Earthquakes Earthquakes USA: USA: W.H. Freeman and CompanyW.H. Freeman and Company

Bolt, B.A. (1993) Bolt, B.A. (1993) Earthquakes And Earthquakes And Geological Discovery Geological Discovery USA: W.H. USA: W.H. Freeman and CompanyFreeman and Company

Coburn, A. and R. Spence, (1992) Coburn, A. and R. Spence, (1992) EarthquakeEarthquake Protection Protection UK: John Wiley UK: John Wiley & Sons Ltd& Sons Ltd

Further ReferencesFurther References 1. U.S. Geological Survey (1997) 1. U.S. Geological Survey (1997) EarthquakeEarthquakes.Retrieved August s.Retrieved August

20, 2006, from World Wide Web 20, 2006, from World Wide Web http://pubs.usgs.gov/gip/earthq1/intro.htmlhttp://pubs.usgs.gov/gip/earthq1/intro.html

2. 2. Glasscoe, M. (1998, 13th August) Glasscoe, M. (1998, 13th August) Space technology is used to Space technology is used to observe and measure tectonic motion of the Earth's surface. observe and measure tectonic motion of the Earth's surface. Retrieved August 20, 2006, from World Wide WebRetrieved August 20, 2006, from World Wide Web http://http://scign.jpl.nasa.gov/learn/index.htmscign.jpl.nasa.gov/learn/index.htm

3. Encyclopedia Britannica (2006)3. Encyclopedia Britannica (2006) EarthquakeEarthquake . . Retrieved August Retrieved August 20, 2006, from World Wide Web 20, 2006, from World Wide Web http://www.britannica.com/eb/article-9106195http://www.britannica.com/eb/article-9106195

4. U.S. Geological Survey Earthquake Hazards Program (2006). 4. U.S. Geological Survey Earthquake Hazards Program (2006). Retrieved August 20, 2006, from World Wide Web Retrieved August 20, 2006, from World Wide Web http://http://earthquake.usgs.gov/eqcenter/dyfi.phpearthquake.usgs.gov/eqcenter/dyfi.php

5. Wikipedia, The Free Encyclopedia (2006) 5. Wikipedia, The Free Encyclopedia (2006) EarthquakeEarthquake. . Retrieved Retrieved

August 20, 2006, from World Wide Web August 20, 2006, from World Wide Web http://http://en.wikipedia.org/wiki/Earthquakeen.wikipedia.org/wiki/Earthquake