How Were the Hawaiian Islands Formed?

French Peter/Perspectives/Getty Images

The Hawaiian Islands are volcanic in origin, and they formed millions of years ago. According to the National Ocean Service, the islands developed because of a hot spot in the middle of the Pacific Ocean. The consistent eruption of lava fed by the hot spot resulted in volcano formations that rose above sea level to form the islands of Hawaii.

The Hawaii hot spot has been active for at least 70 million years. The hot spot itself is fixed in place, but the plate where the volcanoes were built is moving constantly, tearing the volcanoes away from the active hot spot and carrying them northwest of the Pacific Ocean. The constant movement of the plate stops volcanoes from erupting, but it also allows new volcanoes to be formed. Lo’ihi seamount, an active volcano south of Kilauea, is the firstborn from the countless eruptions and plate movements.

Each island in Hawaii is composed of an active volcano. The Big Island, which is the largest of the Hawaiian Islands, is home to five major volcanoes, including Mauna Loa, the largest volcano on Earth. Aside from the eight major islands, the Hawaiian archipelago is also composed of islets, atolls and underwater seamounts in the North Pacific Ocean.