Glaciers were a big deal in Wisconsin. We had studied their impact on the landscape during an introductory portion of studying early history of Wisconsin. My students learned about the five regions of our state and how the glacier affected the landscape. I knew I needed to connect today's glaciers at this point and get them to understand that glaciers still are active and change the Earth's surface.
To help students understand how a glacier moves, I wanted them to see a glacier calve. This video clip is exciting because it is as if you are in the boat with these people! I asked them if they would like to take a tour that got so close to the glacier? I also asked them to think about what kinds of things the glacier was bringing with it as it calved. Several students offered up ideas about gravel and one student commented that anything that was in its way would go with it into the ocean. He said that standing on one was probably not a good idea!
We discussed how the ice broke of and then we noticed how it pushed up from the ocean as if it were a huge whale breaching. I explained that these glaciers are melting slowly and this is occurs daily. I told them that we were going to watch a glacier melt right in our classroom! We moved to the science lab to begin our work. This visual strategy was important as we moved into the investigation using our own glaciers!
An All Afternoon Process: You will need a whole afternoon to observe and sketch the glacier. My math class starts right after lunch and so I started the process as soon as they were back from recess. I had to interrupt my math class for them to take turns looking at their glacier throughout the afternoon to accommodate the ice melting process. I planned that math lesson well so that the interruptions were during a skill practice time.
Materials to be set up the day ahead of time: 1 cup of fine sand & soil mix, a smaller size bread pan, large flat tray with a hole at the end for drainage, bucket to catch the water or a sink. A jelly roll pan works well too. I used one of those gummy sided clips, (that is used to hold papers on the wall ) and stuck it to the pan about a quarter of the way down to keep the glacier from sliding down.
Directions: Create a glacier for each group of students by placing 1 cup of sand & soil mixture in the bottom of two bread pans. Fill it with water and freeze. The next day, remove the ice chunks from the bread pans and place it in the tray. Just before students started, I propped the pans up at a 45 degree angle so that the water would flow and pool at one end. This helps students see how water moves and helps it move the soil a little more aggressively for them.
We began: Students sketched the ice chunk and noted the time at the beginning on their "There’s a Glacier in the Classroom" data sheet. I had them photograph the glacier and sketch from the photo. This strategy ensured that the time and the sketch are accurate. Otherwise, it melts as they are sketching. I instructed them to describe exactly what they saw in precise language. This strategy also creates a little photo journal that they can swipe forward to see the process again.We took turns measuring the end that is on the far end of the slope. I did this because it will show the most diverse change. It is a point where the gravity and water flow have the most effect on the sand/soil.
After we finished the first sketch, I stopped to have them share questions and noted them on the board. Questions were rich. They wondered if one would melt before the other? They wondered how the sand would change? These questions help them be accountable for their investigation as NGSS Science and Engineering Practices demand.
After all the notebook writing was done, I asked them to predict based on their prior knowledge about ice and glaciers.
Every half hour, we went back into the lab, photographed, measured and described what was happening on the data chart. I stopped them at the second observation to be sure they understood by asking, "What are we modeling?" We kept going until the end of the day with our last read at 1:45. Glacier 1 & Glacier 2 had melted almost completely at this point. They had noted differences in how the sand changed and students were ready to discuss what they had seen!
As students finished up their final drawings, I asked them, "What surprised you?" There answers were filled with excitement. We discussed the measurements and how the sand shifted lower, higher and then lower again. We talked about how there are rivers within the glaciers in the real world that moves debris and flows the melting process along. I asked, "What if we had used a heat lamp?". They understood that more heat would speed up the melting process and the water would flow faster."Does it change the surface of the land?," was asked to help students think about the standard. Some students had begun writing on their short answer sheet. I stopped and went over each question. I focused on the back questions that expect the student to combine the other two labs and focus on what the model shows us about real life. In my reflection, I talk about what needs to be done so that this is understood better. I assigned the writing to be completed at home.