1. The Hot Spot:
* A Plume of Magma: A hot spot is a fixed point within the Earth's mantle where a plume of unusually hot magma rises from deep within the Earth.
* Volcanic Activity: This rising magma melts through the overlying crust, creating volcanoes.
2. Plate Movement:
* The Pacific Plate: The Hawaiian Islands are located on the Pacific Plate, which is constantly moving northwestward.
* Volcanic Chain: As the Pacific Plate moves over the stationary hot spot, a chain of volcanoes is created. The oldest volcanoes are furthest away from the hot spot, and the youngest are closest.
3. Age Progression:
* Volcano Formation: As the Pacific Plate drifts northwestward, the hot spot continues to erupt, forming new volcanoes.
* Erosion and Submergence: Once a volcano moves far enough away from the hot spot, its supply of magma cuts off. The volcano becomes extinct and begins to erode. Eventually, older volcanoes may sink below sea level.
Example:
1. Hawaii (Big Island): The youngest and most active volcano in the chain, still directly over the hot spot.
2. Maui, Molokai, Oahu: Older volcanoes that are no longer active but still above sea level.
3. Niihau, Kauai: Even older, extinct volcanoes that have undergone significant erosion and are now relatively flat.
4. Emperor Seamounts: A chain of submerged volcanoes extending northwest of Kauai, representing the very oldest remnants of the Hawaiian hot spot.
Summary:
The age progression of the Hawaiian Islands is a direct result of the interplay between a stationary hot spot and the movement of the Pacific Plate. The older islands are located further away from the hot spot because they have been carried northwestward by plate motion over millions of years.
