Computer Methods & Modeling in Geology
Taught by: Kirsten Menking
What is your course Computer Methods & Modeling in Geology about?
This course is designed to teach Earth Science students the process of numerical modeling. In recent years computer modeling has gained importance in geological and environmental research as a means to generate and test hypotheses and to allow simulation of processes in places inaccessible to humans (e.g., Earth's deep interior), too slow to permit observation, or too large to facilitate construction of physical models (e.g., faulting on the San Andreas). Fields within the Earth Sciences now exist in which computer modeling has become the core work of the discipline, yet none of the institutions in our liberal arts comparison group prepares Earth and Environmental Science students for this reality. Furthermore, many geology students report feelings of trepidation, if not downright dread, over the use of mathematics in our science, and feel that they do not know how to apply the mathematics they have learned to real world problems. It was for these reasons, that I decided to create the modeling course.
In the course, students learn the modeling process by constructing simple box models of environmental phenomena in the software STELLA. Once they have gained proficiency with conceptual modeling, they then go on to learn how to program their models in Fortran, the most widely used language in the Earth Sciences today. Phenomena and processes addressed in the course include the global phosphorus cycle, Earth's radiative equilibrium and resulting surface temperature, the flow of heat in permafrost, and radioactive decay of elements and their utility in geologic dating. My objectives in teaching this course are first and foremost to develop students' analytical thinking abilities and quantitative skills, but also to give students background in numerical modeling sufficient to allow them to work with models in their future careers in graduate school, industry, or government and/or to be able to critically evaluate the modeling results of other workers.
What technology did you use to teach the course, and how did it enhance your course?
The course makes use of the STELLA box modeling software package developed by isee systems and Compaq Visual Fortran. STELLA is a wonderful software tool for teaching conceptual modeling and the basics of systems. Using icons for reservoirs and flows, it allows the student to generate fairly sophisticated models without having to know a programming language. A click of the mouse allows boundary and initial conditions to be specified, and an internal graph pad allows the model results to be viewed within the software. Additional features, such as a stick of dynamite used to blow up/delete parts of programs, add whimsy to the software and make it fun for students to use. In addition, a drop down arrow on the model page allows the user to see the mathematics behind the model, a very useful aspect of the software to the teaching of finite difference modeling, and a bridge to the Fortran programming. Compaq Visual Fortran is overly sophisticated for the level of programming carried out in the course, yet has useful features helpful in teaching, such as color coding of different parts of the program text, and a built-in compiler and debugger, and it is for these reasons that I selected it for the programming part of the course.
The Student Response
How have your students responded to your use of technology?
I have administered a questionnaire to the students in Geology 361 at the end of the semester each of the two times I have taught it. Students reported that they felt the course was highly effective in teaching the basics of system dynamics and how systems could be modeled, that they found the iconographic structure of STELLA very useful in learning modeling, and that the STELLA modeling prepared them well for the work in Fortran. Responses to the question "how would you describe the impact of this course on your general understanding of system dynamics and of how systems can be modeled?" included:
"Before I took this course I had no idea how people knew what they knew about systems with large scales and long timescales. Now I see how useful a computer model can be to understanding this. I also learned that the models can be simple but still give a lot of information. This class has been SO useful in making geologic problems realistic."
"This class had a tremendous impact on my general understanding of modeling and system dynamics. It has helped me to realize how valuable modeling can be in geology and how to go about modeling a problem."
"Highly effective, I now understand what modeling a system consists of and can think about such relations mathematically much better than I could six months ago."
Students gave the following responses to the questions: "How do you feel about modeling now that the course is over? Can you foresee using it in the future to study some geological or other process? Has the experience in this course turned you off and made you never want to touch a model again? Something in between?"
"I'm really glad I took this course, and I want to make use of models in the future."
"I can totally see myself using modeling in the future. I would like to get more data and add more complexity to my independent model."
"I really like and appreciate all that modeling can do for me, and plan to use it in the future."
"I find modeling enjoyable, despite the frustrations of the trouble shooting process. I can certainly foresee using modeling in the future, and this course has helped to turn me on to modeling."
In response to the question "Did the course have any impact on your understanding of the usefulness of math in geology?" students said:
"Yes, this is one of the only courses which has done so."
"Yes, it had a huge impact. This class showed me that calculus is very important in the study of geology. Because of this class I'm planning on taking calculus."
"DEFINITELY!! I am going to try and improve my math skills and fix any holes and deficiencies I have."
"Yea - now I wish I'd taken more math. - I may take some next year but haven't had any since freshman year. For the practical applications such as this you have to be able to truly understand it, not just do it."
What kinds of challenges did you face when teaching this course?
The primary challenge that I face when teaching this course is that I am teaching it alone. As students create their models, they typically need assistance debugging them, and the very small syntactical mistakes that they make can take me many minutes to find. This means that as I work with one student, other students have to wait for my attention, sometimes for a very long time. For some students, this leads to a great deal of frustration. I hope to address this problem the next time I teach the course by having a former student of the course act as a teaching assistant.back
What new directions would you like to explore in your teaching with technology?
In recent years, I have begun to explore using the tool of Geographic Information Systems in my courses. Like STELLA, the software ArcGIS facilitates spatial and temporal hypothesis generation and problem solving, and I look forward to incorporating into my classes where it makes sense to do so.