1. Using IRIS and other seismic data resources in the classroom John Taber, Incorporated Research Institutions for Seismology

2. Overview IRIS Earthquake Browser Estimating seismic hazard Exploring seismicity in Oklahoma Visualizations, animations, and waveforms – Recording and analyzing data from an educational or research-grade seismometer – Viewing a set of seismograms from an earthquake – Exploring regional tectonics using focal mechanisms – USArray ground motion visualizations

3. Yesterday’s Earthquake

4. As recorded in the US

5. As a story Jointly produced with Univ. of Portland, collaborative content from USGS, UNAVCO and others

6. Tectonics http://www.iris.edu/hq/retm

7. IRIS Earthquake Browser - www.iris.edu/ieb My_link_for_this_image

8. IRIS Earthquake Browser - www.iris.edu/ieb Can use for introduction to plate tectonics – Explore plate boundaries – Turn plate boundary lines on and off – Interactive 3D viewer General exploration of spatial distribution of local and regional seismicity

9. Estimating seismic hazard You have been asked to compare the seismic hazard in two regions to determine which is safer for building a new manufacturing plant. 1.What type of data would you need to collect to make the comparison? 2. How could you express your findings in a quantitative way?

10. Earthquake hazard from a single fault Would like to know How often do the biggest earthquakes occur? When will the next big one occur? Extend earthquake history with geologic record

11. Earthquake recurrence along a single fault Sieh et al., 1989 With a partner: Determine when the next Pallett Creek earthquake is going to occur. Can you estimate the uncertainty in your answer?

12. Earthquake recurrence along a single fault can be highly variable: probabilities hard to assess M >7: mean = 132 yr Standard deviation = 105 yr Estimated probability of next earthquake in 30 yrs is 7-51% -> Nearly Random! Sieh et al., 1989

13. How can we deal with unpredictable nature of individual faults? Try regional approach Use the rate of earthquake occurrence in one time period to forecast earthquake activity in another time period Combine results from multiple faults Consider more than just the biggest earthquakes

14. IRIS Earthquake Browser - www.iris.edu/ieb

15. Estimating seismic hazard Steps: Select a region of the world that is of interest to you Interrogate the earthquake catalog to determine the number of events that occur in a 25 year period – Set the Time Range – Set the Magnitude Range In an Excel spreadsheet, record the total number of events for each magnitude range Determine the number of earthquakes/year for each magnitude range Plot the magnitude range vs the number of earthquakes/year

16. Questions to discuss with a partner Given the range of the data, what sort of plot gives the clearest representation of the data? Do you see any patterns or trends in your data? How does your plot compare to your partner’s plot of a different region? What is the likelihood of earthquakes of magnitude 6.0 or greater and 7.0 or greater occurring in the next year in the 2 regions? What is the likelihood of these events occurring in the next 100 years in each region?

17. Earthquakes, Magnitude >3.5, 1973-2007

20. Earthquakes/year Magnitude California (blue) and Eastern US Earthquakes (red)

22. How often does a M6 earthquake occur?

23. How often does a M7 earthquake occur?

24. Real, imperfect data set

25. Interpretation questions How can you use the seismicity information to estimate which of your two regions would be a safer choice for the manufacturing plant mentioned at the beginning of the exercise? What are some assumptions, limitations, and potential sources of error in drawing conclusions about long-term seismic hazard using the above technique?

26. Customizable USGS Seismic Hazard Maps Submitted draft exercise explores hazard map http://geohazards.usgs.gov/eqprob/2009/index.php

27. Oklahoma seismicity - www.iris.edu/ieb For Oklahoma : Compare 5/1/95-5/1/05 and 5/1/05-5/1/15 Magnitude 2 and greater Count the earthquakes

28. Rapid E a r t h q u a k e V i e w e r Determine global travel times and infer Earth structure Rapid Earthquake Viewer Developed and maintained by Univ S. Carolina

29. Real time data streaming and simple analysis – Simple filtering, arrival picking, locations, magnitudes Recording and analyzing seismic data Jamaseis

30. Recordings from the Global Seismic Network

31. Visual sorting of normal, reverse, and strike-slip mechanisms Can explore distribution in a subduction zone IRIS main menu: Data and Software > Products – Select Moment Tensors, then Quick links – http://www.iris.edu/spud/momenttensor Focal mechanism animation available Exploring regional tectonics using focal mechanisms

32. Select a region and a submitted velocity model and generate a cross section Fate of slabs Crustal and upper mantle thickness under mountain ranges Investigating Earth structure using tomographic models

33. USArray Ground Motion Visualizations Visualizations exist for all parts of lower 48

34. EPO web p a g e f r o m w w w. i r i s. e d u Feedback? Comments? Questions?

35. EXTRAS

36. Selection from focal mechanism animation