1. Exploring Planet Earth braile@purdue.edu www.eas.purdue.edu/~braile Updated October 2011 The AS-1 Seismometer and AmaSeis Software – An Effective Educational Seismograph Larry Braile Department of Earth and Atmospheric Sciences Purdue University IRIS Seismographs in Schools Program http://www.iris.edu/hq/sis http://web.ics.purdue.edu/~braile/new/AS1AmaSeis2008.ppt

2. The AS-1 Seismometer

3. Inexpensive (~$500); easy to set up and use Demonstrate how a seismograph works “Make your own earthquake” Monitor earthquakes – local (~M3+), regional (~M5+), worldwide (~M6.5+) Connects to IRIS data archiving and analysis software (written by Alan Jones) on Windows computer; maintain EQ catalog Display, filter and analyze seismograms Calculate epicenter-to-station distance from S-P times; calculate magnitude

4. 24-Hour Screen Display Extracted Seismogram (developed by Alan Jones, SUNY Binghamton, NY) IRIS AmaSeis Software

5. January 22, 2003, M7.8, Colima, Mexico earthquake recorded on an AS- 1 seismograph and AmaSeis software at West Lafayette, IN. Distance = 26.01 degrees. Seismogram was filtered from 0.001 – 0.1 Hz.. Maintaining a catalog of recorded earthquakes is a convenient and educational exercise associated with educational seismograph operation. Data entries require observation and analysis of seismograms, retrieving information from the internet and performing simple calculations. Monitoring Earthquakes

6. Determine distance from S-P time Using the AmaSeis travel time curve tool to determine the epicenter-to-station distance from the S-P arrival times. January 22, 2003, M7.8, Colima, Mexico earthquake recorded on an AS-1 seismograph and AmaSeis software at West Lafayette, IN; Distance = 26.01 degrees.

7. Drawing an arc on the globe for Oaxaca EQ for TUC station.

8. Comparison of calculated earthquake to station distance and distance estimated from S – P times N = 169; Standard Deviation = 1.89 degrees http://web.ics.purdue.edu/~braile/edumod/MagCalc/AS1Results.htm

9. Calculating Magnitude Inputs: Distance (degrees), Amplitude (digital units from AmaSeis screen; converted to displacement by the calculator), and wave period (seconds). Online Earthquake Magnitude Calculator for the AS-1 Seismograph

10. MS Magnitudes: N = 270; Standard Deviation = 0.25 magnitude units. mb Magnitudes: N = 520; Standard Deviation = 0.26 magnitude units. mbLg Magnitudes: N = 34; Standard Deviation = 0.35 magnitude units. Comparison of AS-1 and USGS Magnitudes

11. Comparison of AS-1 and USGS Mw Magnitudes AS-1 mb, MS and mbLg magnitudes correlate well with M (Mw, moment magnitude) except for the largest earthquakes

12. Exploring Planet Earth AS-1 Seismograph Resources AS-1 Seismograph Information (Links): http://web.ics.purdue.edu/~braile/indexlinks/as1.htm View Near Real Time Seismograph Displays: http://www.iris.edu/amaseis/schools/ Teaching Modules and Tutorials: http://web.ics.purdue.edu/~braile/edumod/as1lessons/as1lessons.htm WLIN Seismograph Earthquake List: http://web.ics.purdue.edu/~braile/edumod/as1lessons/InterpSeis/EqList.xls WLIN Earthquake data for download (as large as 50MB): http://web.ics.purdue.edu/~braile/new/2004.ziphttp://web.ics.purdue.edu/~braile/new/2004.zip also, 2005.zip, 2006.zip, 2007.zip, 2008.zip, 2009.zip, 2010.zip Instructions for downloading 2003 (etc.) data to the AmaSeis folder on your computer: http://web.ics.purdue.edu/~braile/edumod/as1lessons/UsingAmaSeis/download2003.htm