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My understanding is that the Hawaiian islands were produced as the Pacific plate moved over a stationary hot spot, which sent magma burning up through the plate as it passed over, forming a trail of volcanic islands on top.
But why dots instead of a line? In other words, why did that process produce islands instead of a continuous piece of land? Does the rising magma start and stop periodically?
Don't be mislead by the subaerial part, it is actually a ridge on a large scale but neither the lava production rate nor erosion rates are constants. That leaves the ridge with higher and lower parts, as well as gaps. Furthermore reef building biocenoses change shape and appearance of the eroding volcanic edifices.
Hawaiian (and other like for instance the Canarian) volcanoes go through stages during their lifetime with different production rates and magma composition. Connections to the magma chamber(s) may remain in place for some time while the volcanic edifice moves relative to the magma source(*), until it has moved so far away that rising magma seeks new ascent channels to rise and deformation forms new dykes and cracks and so it may erupt from different vents, and that from a possible complex and subdivided magma chamber(s) fed by the plume underneath.
That process may leave an appearance of single detached volcanoes like e.g. M. Loa and M. Kea, but they are just similar things at different stages. Many volcanoes never reach a subaerial state and remain submerged, contributing to the appearance of detached islands.
(*) i would say, whether it is the plate that moves or the plume or the connections between plume and magma chambers is mostly irrelevant. Base argument is that the rate is not constant and eruptions may seek different paths during time. As to the exact why and how, that's ongoing discussion.
Hawaii s a chain island made of various continuous eruptions. It's like a conveyor belt. As the hotspot deposited lava cooling under the sea..... the island would form.....as the Pacific plate moved....the hot spot remains in position and starts over. Some mountains never made it to the surface.... Hawaiian chain is over 26 million years old.....but its youngest island is only half a million.....and 2600 miles if islands that after millions of years eroded into the small atolls [midway, etc.] You see now.
