Long-term field-based studies in geoscience teaching

Multiyear measurements of geologic processes with slow rates of change can provide valuable data sets for student learning in the classroom and opportunities for undergraduate independent research. Here, we describe three projects for which data have been collected for 34, 20, and 10 yr, respectively: the erosion of a small meandering stream, the weathering of limestone cubes, and local stream hydrology/chemistry, including discharge, dissolved and suspended load, and major ion chemistry. These data have been used at all levels of the curriculum in various ways, from visualizing basic geologic principles in introductory courses to sophisticated statistical analysis and interpretation in upper-level courses, always in a context of student research leading to discovery about Earth systems. Depending on the project and the schedule for data collection, students have played a major role in the data collection, synthesis, and interpretation while also learning valuable analytical and statistical skills. Because the data sets are the product of many classes of students, there is a strong sense of ownership of the data and thus significant quality control, making the data sets useful as baseline studies for future projects. Where the study requires frequent and time-sensitive sampling, it is more difficult for students to collect data or make measurements. They may, however, have a hand in analyzing the samples collected in order to learn analytical and interpretive techniques. In some cases, these projects have expanded to include new long-term data sets that augment the original studies.