Without volcanoes, there would be no Hawaii. The eight primary islands that make up this archipelago owe their existence to a roiling spot of magma deep under the ocean floor known as the Hawaii hotspot.

The hotspot is thought to lurk for now below the archipelago's youngest and most active landmass, the Big Island of Hawaii. Its molten rock fuels the eruption of this island's four active volcanoes: Mauna Loa, Kīlauea, Hualālai, and the offshore underwater volcano Lōihi.

While the hotspot itself remains largely stationary, the overriding Pacific plate does not; it creeps northwest at a rate of three to four inches each year. Because of this, the volcanic activity on the planet's surface also shifts. That movement formed