Earthquakes, Volcanoes, Tsunamis, Oh My!

By Michelle Hall-Wallace and C. Scott Walker, University of Arizona

The SAGUARO Project's case study of the January 17, 1994, Northridge earthquake in California allows students to investigate both the geological and societal ramifications of a major earthquake in a large metropolitan area.

Experienced instructors know that teaching introductory level students about global earth processes, geologic hazards, or environmental science can be a challenging task. The full richness of these topics requires students to be able to organize and integrate scientific and societal information, to have a basic knowledge of world geography, and to be capable of visualizing and analyzing three-dimensional spatial and temporal relationships. Increasingly, instructors are turning to technology to address these challenges, but often these technology resources are relatively static, allow only limited interactivity, and prove to be little more than electronic textbooks with a few flashy animations. The need for an involving and flexible teaching resource that inspires students to explore complex data sets and dig into the science underlying them persisted. Persisted, that is, until now.

At the University of Arizona, Tucson, Arizona, students in the Geologic Hazards and Society ("Hazards") class are using GIS to learn about natural disasters. Using a series of GIS-based curriculum materials produced by the Science and GIS Unlocking Analysis and Research Opportunities (SAGUARO) Project, the introductory-level nonscience majors dive into guided explorations of tropical cyclones, tsunamis, volcanoes, and earthquakes. The students, armed with only a five-minute tour of ArcView, diligently work their way through the activities with minimal assistance, often independently. In the process, they perform sophisticated queries and theme-on-theme (overlay) operations, calculate statistics, and analyze computer animations. By the time they've finished an activity, they have learned about fundamental earth science relationships such as tropical cyclone formation and sea surface temperature or earthquake magnitude and frequency, and they have also unknowingly explored some of the "higher end" functionality that makes GIS such a potent tool for understanding our world.

Traditional GIS education takes an "under-the-hood" approach to GIS, essentially emphasizing teaching about the software and hardware underpinnings of GIS. The activities the Hazards students are using turn this notion on its head, and instead they use GIS as a powerful teaching tool to convey information about our dynamic and sometimes dangerous planet. Advantages of this "teach with GIS" approach are evident for both the Hazards students and the course professor.

GOES9 images of Hurricane Georges allow students to relate the storm's appearance to the pressure and wind speed data at the storm's center.

"The students can focus their attention on learning science using the full complement of ArcView software's capabilities," says course professorDr. Terry Wallace. "For example, students determine the sea surface temperature at which tropical cyclones form by performing a unique value classification and graphing the number of cyclones in each temperature category."

The exercise involves ArcView software's Legend Editor and focuses on determining the minimum temperature required for cyclones to form (80� F [26.7� C]). Another part of the cyclone module has students perform a select-by-graphic operation to calculate tropical cyclone wind speeds in different portions of the Atlantic Ocean. Again, the emphasis is on the relationship between cyclone wind speed and location, not the spatial selection process. Nevertheless, the exposure to these and other GIS procedures in the context of answering specific scientific questions provides a foundation for spatial thinking and problem solving. For Dr. Wallace, the advantage is straightforward: he is able to teach science without having to be an ArcView expert.

The activities the Hazards students complete cover different types of natural disasters but are all crafted from a common pedagogical framework. This design emphasizes the following three factors critical to effective GIS-based teaching.

Simplifying the Use of the Tool

First, simplify the use of the tool. This means that many of the multiple step procedures confronting the students are streamlined or automated. For example, when the Hazards students investigate the role of heat in tropical cyclone formation, they load prebuilt legends that categorize the formation points based on the season in which they form. When they switch projections in the plate tectonics activity to view the Eurasian and North American plate boundary extending across the North Pole, they click an icon rather than navigate through the View Properties menu procedure. Numerous other examples show that by eliminating potential sticking points up front, the Hazards students encounter fewer frustrating obstacles, allowing them to stay focused on science concepts and explore data more freely and deeply.

Progressing from Global to Regional to Local Scales

Structuring the activities to progress from global to regional to local scales is also an important design criterion for guiding student learning. Global scale investigations introduce the fundamental science concepts and driving forces behind a particular earth process, review pertinent geography and nomenclature, and set the stage for the larger scale investigations. The regional and local scale studies focus on a smaller area and deal with issues and problems of interest to many communities. Gradually focusing on more local scales helps students relate global phenomena to a world they recognize.

In 1993 the Hokkaido earthquake triggered a tsunami that devastated the Japanese resort town of Aonae. The investigation includes a NOAA animation that models the tsunami's behavior as it makes landfall.

As a Hazards student explores tsunamis, for instance, he or she starts out by looking at the 1960 Chile earthquake and tsunami, an event whose extent, duration, velocity, and other spatial characteristics are best observed and quantified at the global scale.

The scale is then increased to investigate the regional effects from the 1964 Alaska earthquake tsunami. After measuring the extent of the fault rupture zone that triggered the tsunami, students launch a computer-modeled re-creation of the event and observe the interaction between normal tidal activity and the tsunami wave front as it sweeps into Seaside, Oregon. The activity concludes with a still larger scale study of the 1993 Hokkaido earthquake and the 10-meter tsunami that devastated the resort town of Aonae on Okushiri Island. Students manipulate another computer simulation of the wave, then use ArcView to determine the advance warning residents had, based on the town's distance from the trigger event's epicenter. The students' chilling calculation: Aonae residents had six minutes advance notice, which explains the 120 deaths.

Tying Science and Society Together

The final element of good activity design involves tying science and society together as components of an integrated system. Establishing this link is often done in the local scale investigation, as was discussed above with the Aonae tsunami. However, students can explore the link at the global level as well. After examining casualty and economic figures from five major earthquakes since 1950, the Hazards students assess the seismic risk of each of the five countries by querying attribute data describing gross national product, population density, and seismic hazard. This evaluation shows the students how economic and demographic factors play a large role in the seismic risk each country's residents face.

Over the past two years, more than 1,000 college and 1,000 high school students have completed the SAGUARO Project activities. At the college level, where the activities were assigned as homework, greater than 94 percent of the students turned in all of their homework assignments and attained an average score of 85 percent. Both college and high school students expressed in interviews and course evaluations that they enjoyed the activities, especially the dynamic and interactive nature of the GIS views, and the excitement of exploring real data. It is an exciting era for earth science research and an equally exciting phase in the continued evolution of GIS technology.

For more information, contact Dr. Michelle Hall-Wallace, University of Arizona Geosciences Department, Tucson, Arizona (tel.: 520-621-9993, e-mail: Hall@geo.arizona.edu, Web: saguaro.geo.arizona.edu).