Moving Through Soil

 

This week, After School To-Go students learned about aquifers, runoff, and other essential concepts in the Environmental Scientist career! Girls created a filter to observe the flow of polluted groundwater through Earth’s soil.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

First, students discussed soil’s importance to the environment. Soil plays a role as a habitat for lots of critters, a source of nutrients for crops, and a material used to produce foundations for houses and other buildings. Next, students began construction of their own soil filters. Soil and sand were layered in paper cups to represent the naturally-occurring layers of sediment found in the ground. STEM Crew poured dirty and polluted water into each group’s soil- and sand-filled cups as students observed the difference between the filtered water and the original dirty water. While the filtered water looked clearer than the original, it still looked pretty mucky!

 

 

 

 

 

 

 

 

 

Girls then built a model of a well to observe the effects of water moving through the soil as groundwater. With different types of soil and a paper towel roll, students were able to simulate soil’s ability to filter polluted water. When water “polluted” with purple food coloring was poured around the well in the soil, water that collected in the well was red. Girls deducted that the blue pollutants had been filtered, but the red pollutants were able to collect in the well. At the end of the activity, students observed the different soils’ effectiveness as a filter. Sandy soils filter less, while clay soils and soils with lots of organic matter can catch more pollutants!

 

 

 

Sedimentation Rock Cups

 

This week, the girls unearthed the truth about what lies in the top layer of Earth’s crust as they became Soil Scientists!

 

 

 

 

 

Before diving in, Girlstart students learned facts about the composition of soil, including the five layers that make soil up. After learning about the layers, they played a game in order to further cement the information in their mind. The game involved acting out each layer as the STEM crew leader called out a specific layer. When Bedrock was called out the girls fell to the floor, spreading out to be as close to the ground as possible. When humus, the top layer of soil, was called out the girls jumped with all their might trying to be as high off the ground as possible. In the collage above, in the bottom right corner picture you can see the girls acting out their interpretation of subsoil, as you would guess this is the middle layer!

 

 

 

 

 

The experiment began with each group receiving a bag with topsoil, gravel, clay, silt, and grass that they poured out on a plate and analyzed. They used their analysis in order to predict which materials would reside on the bottom and so forth. Following the soil, water was added and the girls mixed the soil mixture to completion and waited for their mixture to settle into layers. As this occurred, the girls watched with amazement and excitement as most of their hypotheses proved correct!

 

 

It’s a Landslide!

This week, students learned about concepts used in the Seismologist career! Girls applied these skills to the problem of a landslide in a small town.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

In small groups, girls used baking pans and paper ramps to set up their landslide simulators. Small toy houses and a paper bridge were used to model a town located at the bottom of a hill. Sand was poured at the top of the “mountain” to represent loose sediments. Lastly, students took turns shaking their baking pans to simulate an earthquake!

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Girls used a modified scale, similar to the Richter scale, to shake their baking pans harder and simulate a stronger earthquake. After 5 trials of stronger and stronger quakes, students compared the resulting landslides in their journals. Larger sediments, like gravel and pebbles, were added to the sand. Students tested the effects of earthquakes with these materials and brainstormed solutions to the problem of property damage after landslides.