The net reslut of this action is thermal heating of the oceans, at key positions, which in turn reaches the surfaceto be carried aloft into the atmosphere to become part of our surface weather pattern system. As the oceans are heated winds of a high velocity are created and driven over the land areas due to temperature differential. In the Pacific Ocean there are ocean basins - volcanoes, of which there are estimated to be about 20,000 on the ocean bottoms of the world. Some of these form single mountains, and others join with other volcanoes to form ridges. The highest ones rise above the surface of the water as islands, which in many cases linear groups such as the Hawaiian Islands.
Island groups are simply the highest summits of ridges.
Many island groups of the Pacific are linear in form, with the largest and highest island of the group at one end and the lowest and smallest at the other. This feature is true of the Hawaiian Islands, explained as the result of intermittent movement of the tectonic plate over what is called a hot spot. Molten volcanic material is ejected from it and results in the formation of a large mass of material if the plate pauses for a sufficient length of time at the spot. In this way a volcanic island, or ridge, is built. The plate moves, and another part of it lies over the hot spot, receiving fresh volcanic material.