The answer is;
A crack forms in oceanic crust.
Volcanoes erupt under the ocean.
Molten rock rises up through the crust.
New material pushes older rock away from the ridge.
Seafloor spreading occurs in divergent boundaries where two tectonic plates are moving away from each other. As the plates diverge, the void is filled up by upweling magma from the mantle. This causes an eruption at the boundaries causing a cascade of mountains along the ridge. Therefore, the closer to the ridge you get, the newer the crust is.
Is there a picture for this?
Answer: 1
Explanation:
http://www.mayfieldschools.org/Downloads/protein_synthesis_review_worksheet.pdf
The reason is two fold, the first is the active volcano of Kilauea implies there is a lot of heat under the big island of Hawaii, and that heat causes the island to be buoyed up. However, the other islands do not have active volcanos, are colder, and have subsided, the 2nd is, because the volcanoes on the older islands are dormant, those islands are and are no longer growing and are steadily eroding away.
