As the tectonic plates continue to move over a stationary hot-spot, the volcanoes break away and move along with the plate allowing new volcanoes to form in their place such as the Hawaiian Islands.
Hot Spots
A volcanic hot spot is an area in the mantle from which heat rises in the form of a thermal plume from deep within the Earth. Higher heat and lower pressure at the base of the lithosphere melts rock and forms magma. The magma rises through the cracks in the lithosphere and erupts to form volcanoes. As the tectonic plates continue to move over a stationary hot-spot, the volcanoes break away and move along with the plate allowing new volcanoes to form in their place. This plate tectonic movement over a hot-spot results in chains of volcanoes, such as the Hawaiian Islands.
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CauseHeat generated in Earth's core creates convection currents in Earth's Mantle which may cause a rising mantle plume in the middle of a tectonic plate far from tectonic plate boundaries where most geologic activity occurs.
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Effect
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Hot Spots are Volcanoes that DO NOT form along Plate Boundaries
Land-Forms & Geologic Activities
Real-world Example: |
Hawaii is a Famous Hot Spot
The ages of the Hawaiian Islands
correspond directly with their positions. The oldest Hawaiian island of Kauai is approximately 5.1 million years old, followed by Oahu at 3.4 million years old. Molokai is next, at 1.9 to 1.8 million years old; Lanai, at approximately 1.3 million years; and Maui, at 0.8 to 1.3 million years old. The oldest parts of the Big Island of Hawaii are less than 0.4 million years old, and new lava flows consistently add brand-new land. |
The hot spot remains stationary, while the Pacific plate moves in a northwesterly direction at a rate of approximately 2 to 4 inches per year. The movement carries the volcanic islands away from the hot spot, making them dormant. Meanwhile new, active volcanoes form at the hot spot, which today is underneath the Big Island of Hawaii.
Video Guide:
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Topic Tips
- Hot spots like Hawaii are extremely unique in that they are some of the few active volcanoes that are NOT located along a plate boundary.