AmoleSpectra2013. What are ? The resulting vibrations that occur from rocks sliding past one another...

download AmoleSpectra2013. What are ? The resulting vibrations that occur from rocks sliding past one another at a fault Caused by pressure experienced at plate

of 28

  • date post

    18-Dec-2015
  • Category

    Documents

  • view

    212
  • download

    0

Embed Size (px)

Transcript of AmoleSpectra2013. What are ? The resulting vibrations that occur from rocks sliding past one another...

  • Slide 1
  • AmoleSpectra2013
  • Slide 2
  • What are ? The resulting vibrations that occur from rocks sliding past one another at a fault Caused by pressure experienced at plate boundaries Energy is released as seismic waves Seismic waves create the shaking
  • Slide 3
  • The Ring of Fire
  • Slide 4
  • Earthquake Features Focus- exact point inside Earth where quake originates Epicenter- Point on surface directly above focus Energy travels outward from these points in the form of waves
  • Slide 5
  • Types of Seismic Waves Primary or P waves- Longitudinal From focus Fastest (arrives first) Secondary or S waves- Transverse wave From focus Slower (arrives second) Surface waves or L waves- Circular motions Up and down Back and forth From epicenter Moves across surface Slowest (arrives last) Most destructive
  • Slide 6
  • Slide 7
  • Measuring Earthquakes Three Seismograph Difference between arrival times allows seismologists to calculate the distance to the epicenter Draw three circles with radii being the distance to epicenter. The overlapping is the location of the epicenter
  • Slide 8
  • Measuring Earthquakes The Richter Scale is used to measure the energy (magnitude) of the earthquake Does not predict severity/damage Building construction Depth of focus Soil composition and saturation Type of rock Mercalli scale rates the quakes effect of surface (intensity)
  • Slide 9
  • MagnitudeEarthquake EffectsEstimated Number Each Year 2.5 or less Usually not felt, but can be recorded by seismograph. 900,000 2.5 to 5.4 Often felt, but only causes minor damage. 30,000 5.5 to 6.0 Slight damage to buildings and other structures. 500 6.1 to 6.9 May cause a lot of damage in very populated areas. 100 7.0 to 7.9 Major earthquake. Serious damage. 20 8.0 or greater Great earthquake. Can totally destroy communities near the epicenter. One every 5 to 10 years Richter Scale
  • Slide 10
  • 7.8 magnitude (China)
  • Slide 11
  • San Francisco, 1906
  • Slide 12
  • Alaska Earthquake 1964
  • Slide 13
  • Tsunamis are Ocean Earthquakes
  • Slide 14
  • Seismic Waves and Earths Interior FactObservationTheory Waves change speed and direction when the density of the medium changes Velocity of seismic waves are different t different locations The Earth is composed of different layers containing different materials S waves are transverse and cannot pass through liquids S waves do not reach the side of Earths core opposite the focus Part of the Earths core must be liquid Seismic waves can be used to investigate the Earths interior. http://www.pbs.org/wnet/savageearth/animations/earthquakes/
  • Slide 15
  • Slide 16
  • An opening in Earths crust through which magma has reached the Earths surface Release molten rock, ash, and gases Often form hills or mountains as lava builds and cools Generally have one central vent Magma that reaches the surface is called lava Most occur at convergent plate boundaries
  • Slide 17
  • The Ring of Fire
  • Slide 18
  • Slide 19
  • Types of Volcanoes Shield Composite Cinder Cones Seamounts Hot spots
  • Slide 20
  • Shield Volcanoes Magma rich in iron and magnesium Flows great distances Mild and frequent eruptions Gentle slopes Some of the largest
  • Slide 21
  • Shield Volcanoes Mauna Loa, Hawaii
  • Slide 22
  • Composite Volcanoes Alternating layers of ash, cinder, and lava Magma rich in silica Trapped gases cause eruptions that alternate between flows and explosions of cinder and ash Steeper slopes
  • Slide 23
  • Composite Volcanoes Mt. Vesuvius, Italy Mt. Rainer, Washington
  • Slide 24
  • Cinder Cone Volcanoes Smallest and most abundant Violent eruptions due to large amounts of trapped gas Only active for short time Steepest slopes
  • Slide 25
  • Cinder Cone Paricutin, Mexico
  • Slide 26
  • Underwater Volcanoes Called seamounts Look like composite volcanoes Occur at divergent plate boundaries
  • Slide 27
  • Hot Spots Occur in the middle of plates Mantle plumes melt as the rise from the mantle and erupt Mantle plumes under oceans create islands from ash and lava that builds up and breaks through the surface As the plate moves the mantle plume stays creating a chain of extinct volcanic islands
  • Slide 28
  • The Hawaiian Islands