Climate and Topography of Polynesia
Many volcanic islands in Polynesia occur in the interior of a tectonic plate rather than along a plate boundary. These are hotspot volcanoes. A hotspot is a large plume of hot mantle material that rises from deep within the Earth.
A line of volcanoes develops as a tectonic plate moves over a hotspot (see Figure 10.9). The plate continues to move, but the hotspot remains in the same place. When a volcano moves away from an oceanic hotspot, it starts to erode and is eventually no longer visible above the surface of the water.
Figure 10.9 Diagram of a hotspot showing the upper layers of the Earth and a chain of volcanoes on the surface as the tectonic plate moves over the hotspot. (Robert J. Lillie, U.S. National Park Service, 2020. Public Domain).
Source: Robert J. Lillie, U.S. National Park Service, https://www.nps.gov/media/photo/gallery-item.htm?pg=6327391&id=b4df744a-48a9-48a4-b1ce-f658858abf97&gid=62DAEE86-7A72-4797-95FD-D69484194B4D
This work is in the Public Domain.