EARTHQUAKE WATCH

One of the best educational activities in seismology is "Earthquake Watch." In its simplest form, you watch for significant earthquakes and discuss them as they happen during the school year. This activity is a long-established routine for many seismologists and research labs--either in a formal meeting or just casually checking the various online earthquake information sources. Today, with real-time earthquake hypocentral information available at several Web sites, Earthquake Watch can easily be done by students in all places from the university to elementary school classrooms. I know that some elementary school teachers use Earthquake Watch to teach geography by plotting significant earthquake epicenters on a large map during the year. Another good use of Earthquake Watch is to learn about the irregular nature of global seismicity.

Let me share some of the lessons I learned from our Earthquake Watch activity last year in a college-level course. The students followed seismicity in a systematic fashion over an entire semester by updating the class notebook of seismicity. I have found that it is best to do a weekly summary. In a college-level class, you can devise a schedule for the entire semester that assigns students to weeks. One student is the "Earthquake Watcher" for a particular week, although larger classes could assign a team of students to each week. Then, at a set time each week, the Earthquake Watcher has a few minutes to present a summary of global seismicity for the past week.

Although there are several online information sources, the USGS NEIS Web site http://wwwneic.cr.usgs.gov/neis/bulletin/bulletin.html is a good choice for the primary seismicity resource. Student training is quite easy: After you discuss the basic hypocentral parameters, you just need to show students how to access and use this one Web site. For the seismicity statistics aspect of Earthquake Watch, the students would simply report the total number of events in each week with magnitude of 5.8 or larger. This magnitude threshold gave us weekly totals that ranged from one to ten--enough events to be interesting, yet not tedious. You might think that the "lucky" student was the one who had just one earthquake in his week, but think again! All students enjoyed talking about "their" earthquakes, and they were disappointed if only one or two events occurred in their weeks. After eight weeks or so of Earthquake Watch, it is worth plotting a histogram of the weekly totals. There will be variations, and it is fun to "fish" for student predictions about what will happen in the remaining weeks. Eventually, someone will suggest that the pattern may just be the irregularities expected from random occurrence--just what you were hoping to hear! This comment provides the entry point into statistics, and it is possible to discuss this subject at all levels. K-12 students can learn something from the classic exercise of flipping a coin and plotting the "runs" of heads or tails; college students might do numerical tests with the random number generator in a spreadsheet, or even formally study the binomial distribution. Regardless of the level of statistical sophistication, students like to make "predictions" about future seismicity, and then they more eagerly follow the remaining weeks of seismicity.

Well, OK--I have to admit it--I also eagerly follow the Earth's fascinating and irregular weekly display of earthquakes!

(This note refers back to the EduQuakes column in the July/August 2000 SRL: For a link to the EduQuakes online Seismology Lab Manual, go either to the online SRL at http://www.seismosoc.org/publications/srl.html or directly to the EduQuakes Web page at http://AAMC.geo.lsa.umich.edu/eduQuakes/eduQuakes.html).

SRL encourages guest columnists to contribute to "EduQuakes." Please contact Larry Ruff with your ideas. His e-mail address is eduquakes@seismosoc.org.

Posted: 1 December 2000