Hot Spots

Visible in the form of volcanoes or hot springs Hot Spots are stationary place where magma burns through the earth's mantle to reach the surface. This occurs both oceanic and continental plates; Hot Spots are located at transition zones between the inner core and outer crust. There for some unknown reason the earth's mantle is hotter than the surrounding mantle. Hot Spots account for the Hawaiian Islands and the geothermal activity in Yellowstone National Park.

In the case of an oceanic hot spot the magma pushes through the crust on the ocean floor. The material is quickly cooled under the water and the magma is cooled into a gentle slope. As additional material is expelled from the hot spot the slope builds until it eventually reaches sea level forming an island.

As the plate moves at a fixed rate of 3 inches (75 mm) per years eventually a chain of volcanoes is formed. Looking at a volcano's size and its location within a chain indicates the amount of time it was located on the hot spot and when it was created. A sudden shift in the plate will cause the current volcano to be moved off the hot spot and a new volcano to be created. When the plate moves only at its fixed rate the larger volcanoes occur.

Looking at the shape of the chain from oldest to youngest illustrates the plate movement at that particular hot spot.

In the Galapagos Islands the Nazca Plate is subducted under the South American Plate in the Pacific Ocean off the Coast of Ecuador. The subducted material is melted and recycled in the forming of a new volcano. The Hot Spot in the Galapagos, where each of the islands were formed is located under Fernandina.