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.

 

Weathering and Erosion

 

This week, Girlstart students (and future geologists!) reviewed physical weathering, chemical weathering, and erosion before putting different types of soils to the test!

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Before beginning their activity, students worked together to review the difference between chemical and physical weathering. Tables volunteered their ideas, then STEM Crew leaders provided an antacid tablet for girls to observe. Students watched the tablet dissolve in a glass of water and create bubbles as an example of a chemical change. Crew leaders explained that the dissolved tablet had undergone a chemical change. Minerals in rocks can also dissolve – a common example of chemical weathering. On the other hand, physical weathering does not lead to a change in a rock’s chemical composition.

 

 

 

 

 

 

 

 

Girls were then given soil, soil with grass, and sand. Using these materials and a paper cup, students created landforms and weathered them away with water. Because of the loose grains, students found that their sand landforms weathered away more quickly than the other soil types. Finally, students evaluated the significance of their newfound knowledge as geologists. What applications can you think of for this knowledge? Some student answers included protection of homes in floodplains and prediction of landform movement over time.