First students studied landscapes that had experienced weathering and erosion. Students made predictions about why or when the changes occurred. What did the land look like 100 years ago? What might the land look like 100 years in the future?
Next, students conducted a Chemical Weathering experiment using four types of rocks (basalt, limestone, sandstone, and granite). To demonstrate chemical weathering, the rocks were exposed to white vinegar. Students made initial observations, and then waited until the rocks had been exposed to the vinegar for 48 hours. Many physical changes occurred.
Our final science investigation was to help students understand erosion better. Students used “stream tables” to create their erosion models. A mixture of sand and pebbles was used to create the land. Students used a clear container with a small hole to simulate slow, steady rainfall. One group member used an iPad to make a video of the erosion process.
The next day, we returned to the lab, and in three different groups students devised new plans for their erosion models. One group created a stream table with a “flood” on a flat surface. Another group, created a stream table with a slope with “normal rainfall”. Our final group designed a stream table with a slope as well as flood water simulation. Each group found evidence of erosion and weathering that differed based on the different variables.
Our weathering and erosion investigation is a great way to have our students discuss real world problems and imagine what solutions they might create towards change.