Earth Science

Plate Tectonics

Intraplate Activity

Study Tip
The Latin term “intra” means within, therefore you can remember that intraplate activity is geological action that takes place in plates rather than at their boundaries.

Terrestrial Intraplate Activity

Intraplate activity is any sort of geological activity that takes place within a plate away from plate boundaries.

On Land:

  • Hotspots are areas of high pressure on the surface of a plate that causes melting. Mantle plumes that rise through the mantle cause these high-pressure areas.
  • Eruptions at hotspots create volcanoes.
  • Hotspot magmas rarely penetrate through thick continental crust, so hotspot activity on continents is rare.
Study Tip
The Latin term “intra” means within, therefore you can remember that intraplate activity is geological action that takes place in plates rather than at their boundaries.
Study Tip
The same way a person may cast a shadow over another person when they stand under the sun, planets or celestial bodies that have aligned themselves cast shadows over one another as well.

Intraplate Activity in the Oceans

  • The Hawaiian Islands were a product of oceanic hotspot activity.
  • The islands are progressively older toward the northwest because they are further from the hotspot.
  • The Pacific Plate is moving northwest over the hotspot.
  • Since hotspots are stationary in the mantle, geologists can use some hotspot chains to tell the direction and the speed a plate is moving.
The Hawaiian Islands
The Hawaiian Islands are products of intraplate activity in the oceans
Concept Check
  • What is intraplate activity?
  • How were the Hawaiian Islands formed?
  • How are hotspots formed?