earthquake damage near modena, northern italy magnitude and intensity: m w 6.0 & 5.8; mmi vi-vii...

Click here to load reader

Post on 23-Dec-2015

213 views

Category:

Documents

0 download

Embed Size (px)

TRANSCRIPT

  • Slide 1
  • Earthquake damage near Modena, northern Italy Magnitude and Intensity: M w 6.0 & 5.8; MMI VI-VII Date: May 20 th and 29 th 2012
  • Slide 2
  • Todays Presentation: A short lecture activity sequence designed to engage students in learning about EQ epicenter location Activity works for any class size Activity works for any class size Incorporates three separate activities: Incorporates three separate activities: Slinky demonstration of EQ wavesSlinky demonstration of EQ waves Think-Pair-ShareThink-Pair-Share Physical activityPhysical activity Generation of seismic energy by students Generation of seismic energy by students
  • Slide 3
  • Learning about Earthquakes Two learning objectives for students undertaking E&PS 101 at UNM-VC are: Students will be able to describe earthquakes; Students will be able to describe earthquakes; how they occur,how they occur, what the three types of seismic waves are, andwhat the three types of seismic waves are, and how these waves differ.how these waves differ. Students will be able to determine an earthquakes epicenter from seismic wave data Students will be able to determine an earthquakes epicenter from seismic wave data
  • Slide 4
  • p waves p for primary as they arrive first (they are fastest) p for primary as they arrive first (they are fastest) Compressional wave (push-pull motion) Compressional wave (push-pull motion) s waves s for secondary as they arrive second s for secondary as they arrive second Shear wave (side-to-side motion) Shear wave (side-to-side motion) Speed = approx. 60-65% of p-wave speed Speed = approx. 60-65% of p-wave speed L waves Love and Rayleigh waves Love and Rayleigh waves Large amplitude, Long duration, Low frequency Large amplitude, Long duration, Low frequency Speed = Last to arrive Speed = Last to arrive Seismic Waves with a Slinky Body Waves Surface Waves Students really appreciate the alliteration here
  • Slide 5
  • Learning about Earthquakes Two learning objectives for students undertaking E&PS 101 at UNM-VC are: Students will be able to describe earthquakes; Students will be able to describe earthquakes; how they occur,how they occur, what the three types of seismic waves are, andwhat the three types of seismic waves are, and how these waves differ.how these waves differ. Students will be able to determine an earthquakes epicenter from seismic wave data Students will be able to determine an earthquakes epicenter from seismic wave data
  • Slide 6
  • Locating an Earthquakes Epicenter Think-Pair-Share Study the graph on the right. Make two observations about the two lines labeled P and S.
  • Slide 7
  • Locating an Earthquakes Epicenter It is necessary to measure the amount of time between the arrival of P and S waves on a recording We can use the time to read off a distance using our graph
  • Slide 8
  • Think-Pair-Share For the Loma Prieta earthquake, the P-minus-S interval at the Albuquerque seismic station was 2 minutes and 18 seconds (or 2.3 minutes). How far had the seismic waves traveled to reach Albuquerque? Is this enough information for us to determine the epicenter of the Earthquake? Epicenter Distance (km) Travel Time (min) P S Hint: Each square on vertical axis is 20 seconds, and each square on horizontal axis is 200 km
  • Slide 9
  • One Station is not enough With two we can narrow it down
  • Slide 10
  • Locating an Earthquake Epicenter We need at least 3, widely spaced places where we can record an earthquakes energy. 12 3
  • Slide 11
  • Locating an Earthquake Epicenter Seismograph A Seismograph B Seismograph C
  • Slide 12
  • Live Seismic Data Seismogram A: Seismogram B: Seismogram C: Time (milliseconds)
  • Slide 13
  • Locating an Earthquake Epicenter Seismograph A Seismograph B Seismograph C
  • Slide 14
  • SmartPhone Accelerometers Smart phones measure motion E.g. Turn phone to turn picture feature E.g. Turn phone to turn picture feature That means they can also measure seismic energy Search Earthquake App on the internet for more info
  • Slide 15
  • Lets see whats happening around the world http://www.geonet.org.nz/earthquake/drums/ http://www.ees.nmt.edu/Geop/eworm-heli// http://earthquake.usgs.gov/monitoring/spectr ograms/24hr/ http://earthquake.usgs.gov/monitoring/spectr ograms/24hr/ http://earthquake.usgs.gov/
  • Slide 16
  • The Muddiest Point