BEACH-PROFILING AS A MEANS OF ENGAGING GEOSCIENCE STUDENTS ON COASTAL FIELD TRIPS

For introductory Earth Science and Oceanography courses, we developed a beach-profiling exercise that enables students to collect, interpret, and present data from select southern California beaches. Teams of 6 students use a profiling tool that consists of two white polyvinyl chloride (PVC) rods (6 m long) connected by 5 m of plastic rope, which is marked at 0.5 m intervals with brightly painted knots.

Two team-members move the profiling tool from a known position in the backshore down to the average reach of waves. Horizontal distance is measured either by tape or in 5 m increments, leg-by-leg, as the front and back rods are advanced alternately down the beach face. Vertical distance is determined from the back rod position by sighting along the graduated rope until it intercepts the horizon at the front rod. The difference in rope-height between the two rods gives the elevation-change for each leg of the profile. A third person collects sediment samples at 0.5 m intervals for textural analysis, while a fourth records surface features (sand ripples, scarps, berms, etc.). The fifth and sixth team-members inventory benthic organisms in trenches 30 cm deep, 0.5 m apart. Teams present the physical-biological character of a beach in either written, oral, or poster format. Over time, students will have compiled a library of historical changes in morphology for a given beach. When they compare fall profiles with spring profiles for different years, they will fully appreciate the variability of nearshore currents and their seasonal influence on the appearance of beaches.

This structured field project demonstrates how classroom/textbook concepts have tangible field applications. It further allows students to: 1) participate in active learning, 2) observe natural trends or patterns, 3) collect, assemble, and interpret data, 4) develop conclusions, and 5) experience the gratification of independent discovery and achievement.