Plate tectonics and Earth's structure

Rebuild the Bay Bridge!

http://www.newbaybridge.org/classroom/

 


Field Trip - Lawrence Hall of Science

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.


Field Trip - Marin Headlands

Marin Headlands: photograph of Marin Headlands from the Golden Gate Bridge by Christopher BelandMarin Headlands: photograph of Marin Headlands from the Golden Gate Bridge by Christopher BelandSummary
The Marin Headlands contain the geologic record of a great deal of plate tectonic action that can be used to piece together the history of the formation of California. Briefly, around 180 million year ago, the North American plate collided with a now subducted plate called the Farallon plate. As the Farallon plate dove under the North American plate, bits and pieces of the Farallon plate were scraped off. These bits and pieces can be found in the Marin Headlands in several distinctive rock formations: pillow basalts (at the Point Bonita Lighthouse), chert (near Rodeo Lagoon), and sandstone (at Rodeo Beach). By closely observing these rocks and figuring out how they formed, an understanding of how California itself was formed may be inferred.


Project - Earthquake Towers

Earthquake TowerEarthquake 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.


5. Seafloor Spreading

Summary
Students take what they know about earthquake, volcano and mid-ocean ridge distributions (The Big One and Plate Patterns) and put it together with what they know about convection in the Earth’s mantle (Journey Through Earth and Convection in a Pan). They revisit what they know about how earthquakes are created, by the sudden release of energy as plates collide or rub together (but not so much when they split apart). They look for patterns in their world maps, observing that mid-ocean ridges and dense earthquake/volcano zones tend to lie on the opposite side of plates. With this information, they can infer the direction that the plates are moving. Next students build a model illustrating seafloor spreading and discuss the magnetic and seafloor age data that support this model. Finally, students codify the different types of plate boundaries, describing the various features and characteristics of each.


4. Convection in a Pan

Summary
What drives the motion of the Earth’s tectonic plates? Partly, it is convection, the process by which heat energy is transferred by currents in a liquid or gas. Convection currents within the mantle carry tectonic plates along with the slowly moving mantle like giant rafts carried along by a current in a river. To help students understand this idea, soapy water in a pie pan is heated from below and convections currents can be observed forming and moving in the soapy water. Several prelude demonstrations help students recognize that hot things rise and cold things sink.


3. Journey Through Earth

Summary
In the style of Jules Verne’s book Journey to the Center of the Earth, take your students on a walk, using sidewalk chalk to mark the boundaries between the different layers inside our planet. After you pass through each layer, tell your students about the layer of the Earth they just traveled through. This lesson was developed by Eric Muller of the Exploratorium Teachers’ Institute. Here you will find a student handout for taking notes during the walk, a teacher cheat sheet and some assessment ideas. Download a detailed lesson plan for this activity from Eric Muller’s website, originally published in The Science Teacher, September 1995.


2. Plate Patterns

Summary
Kilauea Crater, Hawaii: Pu'u 'O'o crater at dusk. Image courtesy of USGS.Kilauea Crater, Hawaii: Pu'u 'O'o crater at dusk. Image courtesy of USGS.Starting with an earthquake epicenter map (generated by students in The Big One activity), students add information about where active volcanoes are located and the location of the mid-ocean ridges. With the combined information about volcanoes, mid-ocean ridges, and earthquake epicenters, student can trace the boundaries of the Earth’s major plates. On individual student maps containing earthquake epicenter data, they outline the plate boundaries, learn the names of each plate, and use colored pencils to highlight volcano zones and mid-ocean ridges. Future activities in this box have students adding plate direction and speed information to student maps as well as labeling 4 different types of plate boundaries: continent-continent convergent boundaries, subducting convergent boundaries, transform boundaries, and divergent boundaries. The direction and speed of many plates can be inferred from the opposition of mid-ocean ridges on one side of the plate and volcano zones on the other.


1. The Big One

Summary
San Francisco, 1906: Aftermath of the 7.8 magnitude earthquake that caused an estimated 3,000 deaths and $524 million in damage.San Francisco, 1906: Aftermath of the 7.8 magnitude earthquake that caused an estimated 3,000 deaths and $524 million in damage.Students use the USGS World Earthquake Archive to research the major earthquakes in recorded history. Each student is given a range of dates and assembles a table of facts on 10 earthquakes within that time frame. Students present their research and plot the locations of their earthquakes on a large world map, thereby discovering distinct earthquake zones that define the boundaries of the earth’s plates (see the Plate Patterns activity for ways to elaborate on this idea).

Objectives
Can use the USGS Earthquake Archives to research information about historically important earthquakes around the world.
Can diagram and explain what causes earthquakes in general terms.
Can understand and use basic earthquake terminology (fault, epicenter, magnitude, etc.)
Can use latitude and longitude information to plot locations on a world map.

Vocabulary
fault
earthquake
epicenter
magnitude
seismogram
latitude
longitude
tectonic plate