Educational Uses and Evaluation of the NSDL Library Content and Tools

As a part of our proposed research activities, we intent to develop a series of learning modules that college and secondary school teachers can integrate into a pre-existing earth science curriculum. We will design a range of products at levels appropriate to secondary school students, introductory college, and upper-level college students. We expect students at each of these levels to have an increasing degree of sophistication and the ability to tackle questions that are more open-ended. Modules can take several forms. At the simplest level, students can be led through a series of exercises in which they access particular data sets. They may then overlay several types of data and examine the relationships that are highlighted by this juxtaposition. Students may be asked to do the same for several different parts of the world and to then draw conclusions based on their analysis. Finally, students can be encouraged to explore on their own using the tools and data sets available in the NSDL. For example, introductory geoscience students commonly make use of the pattern of global seismicity to map plate boundaries. The inclusion of additional data such as focal mechanism solutions allows students to easily discriminate between convergent, divergent and transform boundaries. They may also wish to explore other questions, such as why Hawaii is so seismically active when it sits in an intraplate setting. Here students can gain a fuller appreciation of hot spot processes by overlaying for themselves maps of seismicity, volcanism and topography. While many printed maps of global seismicity use colored epicenters to indicate increasing focal depth, the ability to display cross-sections of earthquake foci allows students to see immediately the geometry of subducting tectonic plates and to appreciate that not all plates descend at the same angle. These tools allow students to explore parts of the earth that are otherwise completely inaccessible.

More advanced students will benefit from this knowledge system at a higher level. For example, maps of topography, depth to basement, and Moho depth provide students with powerful tools to study the mathematics governing the principle of isostasy. Students can explore for themselves which parts of the Earth's crust are in isostatic equilibrium and which areas of topographic relief are maintained by some other mechanism. As new data are brought on line, we will expand the range of subjects covered by the classroom modules. For example, an oceanography class will be able to examine the relationships between primary productivity, sea surface temperature and ocean currents. Similarly environmental issues such as water pollution, watershed problems and their socioeconomic effects will also be able to studied in a realistic environment with the available data and tools.