Hotspot Islands: Messages from Moving Plates

The Earth’s crust is broken into large tectonic plates that move over the top layer of the mantle. The magma from the mantle can break through the crust at divergent plate boundaries, like at the Mid-Atlantic Ocean Ridge to form underwater mountain ridges. This module focuses on oceanic hotspots and assumes the magma plume from the mantle is fixed in place. Students will look at how the ages of hotspot islands, like the Hawaiian islands, can be used to determine which way large tectonic plates are moving.