My Science Box

Summary
The Lawrence Hall of Science in the hills above UC Berkeley offers fantastic hands-on workshops and exhibits related to earthquakes and plate tectonics. The middle school program, “Earthquakes: Whose Fault Is It?” provides an excellent introduction to seismology. The program begins with a large puzzle of the Earth’s tectonic plates to introduce the idea of plate tectonics and begin a discussion of the location and movement of the tectonic plates. Students then investigate earthquakes and learn to read real and simulated seismograms. Finally, students use seismic recordings to locate the epicenter of an earthquake. Afterward the workshop, the permanent outdoor exhibit, “Forces that Shape the Bay” provides a free-form venue to explore plate tectonics through hands-on exhibits. The other exhibits and planetarium are also worthwhile.

Marin Headlands: photograph of Marin Headlands from the Golden Gate Bridge by Christopher BelandSummary

Earthquake TowerSummary
In this project, students construct drinking straw towers that must withstand the shaking of a shake table. One by one, 250 gram sandbags are loaded onto the towers. The towers must remain standing for 1 minute from the start of the simulated earthquake. Students then have 2 minutes to repair any damage before another sandbag is loaded and the next earthquake test begins. Students quickly learn basic principles of earthquake engineering and architecture as well as the team skills that are a basic part of all science and engineering fields.

Summary

Summary

Summary

Summary

Summary
This lesson is an extension of the GEMS guide: “River Cutters” by the Lawrence Hall of Science (see note below). In the GEMS curriculum, students are introduced to erosion by modeling the formation of rivers in tubs of diatomaceous earth, a silt-like substance into which meandering river channels and deltas form. This lesson builds off of the River Cutters activities by using a combination of sediment types in the models. They observe how gravel and large particles of sand remain in place whereas silt is washed downstream in fast flowing river channels. In contrast, where the water velocity slows as it reaches the newly forming bay, a beautiful silt-covered delta forms. These observations lead students to the conclusion that fast moving water picks up the smaller sediment particles and eventually deposits them in places where the water slows. Students can then take this theory to test it out in real world conditions at a local creek in the Sediment Study Project, observing sediments and water velocity at different sites along a creek’s length. The concept of how sediments are deposited becomes a core feature of subsequent geology lessons and investigations in which the environmental conditions surrounding the formation of large particled conglomerates may be differentiated from small particled shales and siltstones.

Special Note: This lesson plan is written with the assumption that students have some experience using the river models in the GEMS guide “River Cutters”, written by Cary Sneider and Katharine Barrett and produced by the Lawrence Hall of Science. In this guide, students make observations of rivers carved in just silt (diatomaceous earth), sequencing events in time, noticing patterns, recording information, and acquiring the terminology necessary to describe common erosion patterns. My students completed the first 5 sessions of River Cutters although completing the first 3 lessons is sufficient. So as not to infringe upon the copyright of the GEMS unit, only the extension activity is described here.

Summary
In this culminating project, students go out into the field and test their theories about erosion and sedimentation at a local creek. How are sediments distributed along the creek? Does it vary by location (the source, mid-stream, and the mouth)? Does it vary by the velocity of the current? Different classes can collect information for the different study areas. At a study site, they will draw maps, measure the velocity of the current, and collect sediment samples from the creek bed. These samples are analysed back in the classroom for the percent of different sediments they contain. Finally, students stand back and examine their data to try to make sense of the sediments they find. If it is not possible to bring students to a creek, there are many ways to bring the data to them. Collect the sediment samples yourself with photos and water velocity information OR use the Suspended Sediment Database to draw your conclusions. This USGS database provides stream flow and sediment information for over 1,500 rivers and creeks nationwide (see the Going Further section for more information on using the USGS’s database).