Plate Boundary Volcanism Reference: Tarbuck and Lutgens Pages Volcanoes are associated with two of the three types of plate boundaries, these being convergent and divergent boundaries. Very little volcanic activity is seen at transform fault boundaries.  3) Interior of tectonic plates. 2) Subduction zones 1) Ridges (or spreading centers)  Volcanism associated with plate tectonic activity are found in three areas on Earth;

2) within continental plates (Yellowstone National Park) Intraplate Volcanism 1) beneath the oceans (Hawaiian Islands)  This type of volcanism is produced by rising hot mantle material called Hot Spots. Hot spots can be found under continents and the ocean floor.  Intraplate volcanism occurs in two areas;

 An example includes the Hawaiian Islands. Intraplate Volcanism 1) Beneath Oceans  Hotspots within the mantle cause magma to move upward and flow onto the ocean floor forming shield volcanoes and volcanic islands. Magma

 Yellowstone National Park has this type of volcanism. Intraplate Volcanism 2) Within Continents  Hotspots within the mantle cause magma to move upward and flow onto the continental surface forming volcanoes and lava plateaus.

Sample Problem With the aid of a labelled diagram explain how the Hawaiian Island Chain formed. Answer: The Pacific plate moved over a stationary hot spot, forming new volcanic islands directly over the hot spot. The older volcanic islands move with the Pacific plate and travel farther away form the hotspot with each passing year. Over a period of time a chain of islands form. The older islands are no longer fed by the hot spot and therefore become dormant (extinct) or inactive volcanic islands. Ocean Plate Younger Older Hot Spot