Oceans
Investigation 5:
Changes in the Ocean Floor

This investigation will help you to:

When the Earth Moves: Seafloor Spreading and Plate Tectonics,
National Academy of Sciences
Historical account of plate tectonic theory

From Earthquakes to Continental Drift,
National Academy of Sciences
Supporting evidence for the theory of plate tectonics came from the ocean.

This Dynamic Earth: The Story of Plate Tectonics,
USGS
An account of the development of plate tectonic theory.