This is a web-based lesson on plate tectonics. There are now many great sites on plate tectonics, and the objective was to use them to enhance the teaching of plate tectonics. This is obviously a big load of information and could easily be spread over multiple classes.

First I walked through the many lines of evidence supporting the theory using the sites listed below. While I did, students completed the handout. The purpose of the handout was to drive home the fact that plate boundary locations are marked by several unique geologic features (and to make sure students stayed engaged).

Topography of Ocean Basins:

http://web.ngdc.noaa.gov/mgg/image/global_topo_large.gif (topo of all ocean basins)

http://web.ngdc.noaa.gov/mgg/image/2minrelief.html (use to show topo of southeastern Pacific)

http://pubs.usgs.gov/publications/text/topomap.html (detailed topo of part of East Pacific Rise)

Heat Flow:

http://www.geo.lsa.umich.edu/~shaopeng/heatflow.html (global heat flow map)

Volcanoes:

http://volcano.und.nodak.edu/vwdocs/vwlessons/plate_tectonics/part12.html (global distribution of volcanoes)

Earthquakes:

http://www.seismo.unr.edu/ftp/pub/louie/class/100/plate-tectonics.html (global distribution of earthquakes – no plate boundaries)

http://csep10.phys.utk.edu/astr161/lect/earth/plate_boundaries.gif (global distribution of earthquakes – plate boundaries visible)

http://wwwneic.cr.usgs.gov/neis/bulletin/bulletin.html#utc (most recent earthquakes – focal depths of past earthquakes in a given region nicely illustrate plate boundary type, particularly subduction zones!)

Age:

http://web.ngdc.noaa.gov/mgg/image/sedthick.jpg (sediment thickness in ocean basins)

http://EARTHVIEW.SDSU.EDU/TREES/smCfloorage.GIF (age of oceanic crust)

Next we discussed relative plate motions, both present and past, and how the face of the earth has changed dramatically through geologic time.

http://www.solarviews.com/r/earth/plates.gif (actual plate boundary locations)

http://cddisa.gsfc.nasa.gov/926/slrtecto.html (present relative velocities)

http://www.ucmp.berkeley.edu/geology/anim5.html (plate motions over past 750 Ma – backward)

http://www.ucmp.berkeley.edu/geology/anim2.html (plate motions over past 750 Ma – forward)

Finally, we discussed mechanisms that may be driving plate motions.

http://www.earth.monash.edu.au/~greg/Conv.html (simple convection model)

http://www.sciam.com/exhibit/090996exhibit.html (3D global convection model)

http://www.earth.monash.edu.au/~greg/Subd.html (model of subducting slab)