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How the materials are organized and, how we use them...

This introductory course is divided into four modules, one each on the use of gravity, magnetic, DC resistivity, and refraction seismic observations. Each module consists of two main subsections: lecture notes and the interactive case study. Each module requires approximately 24 hours for students at CSM to complete.

The lecture notes, are presented in a hyper-text manner as a series of short WWW pages complete with graphics and links to outside resources. Our implementation allows students to access the material in any of three ways. The first, and from our standpoint most preferable, method incorporates the use of hyper-links to the appropriate lecture notes directly from the case study. Thus, students can start with the case study and in a relatively seamless way, refer to the notes as information is needed to solve the problem. Additionally, the lecture notes are indexed on an outline Web page. Using this page, students can browse those notes containing material in which they are interested or in which they feel some deficiency. This mechanism is provided mainly for those with some background in the material, but who feel a need to review specifics. Finally, students feeling most comfortable in a traditional lecture environment can move sequentially through the notes before becoming involved in the case study. In principle, this latter method is equivalent to presenting a series of lectures on each geophysical method and then doing laboratory exercises to reinforce the concepts described in the notes.

To complete each module, students must respond to a request for bid (RFB). The RFB presents a problem to be addressed by use of a specific geophysical method. Students are asked to respond to the RFB by submitting a proposal that includes a geophysical survey design, a discussion of geophysical noise relevant to the particular survey, estimates of the geological sources of signal that would and would not be detected by the survey, and estimates of the cost of completing and interpreting data from the survey.

In designing their geophysical surveys, students are provided Java-based Web scripts that allow them to model the geophysical response over geologic structures relevant to the particular RFB. The modeling script generates synthetic observations over simple geological models. Using the forward modeling script and estimates of the cost required to perform each step of the survey, students determine optimal survey parameters for the particular problem, in the sense of survey resolution versus survey cost. Because the optimal survey is defined in terms of a rather nebulous cost-benefit trade-off, different participants rarely define surveys based on the same set of parameters. We actively encourage students to try different survey designs. Whatever design chosen, however, it must be justified to the hypothetical client in the formal bid that is submitted in response to the RFB.

After designing the geophysical survey, the parameters defining each student's survey can be entered into a WWW page and students immediately receive a data set that includes random and systematic noises unique to their particular survey. Students are then guided through a data-reduction procedure using relatively simple spreadsheet manipulations. Upon completing the data reduction, students can finally download a modeling script that allows them to interpret their reduced data by superimposing model computations on the data set. A final report is submitted and includes their preferred solution, uncertainty estimates, a discussion of other interpretations that could fit the geophysical observations and reasons why these other solutions are not preferred.