The Hawaiian islands were formed from volcanic activity sourced at an undersea collection of magma called a hotspot. As the tectonic plate beneath the Pacific Ocean moves northwest, the hot spot remains where it is, slowly creating new volcanoes. Due to the land currently over the hotspot's location, the active volcanoes are located around the southern half of the Big Island.
Exposed Fault Lines:
Volcanic rock formed from magma erupted from the nearby volcanos.
Steam erupting through the surface:
Lava in a crater:
The island of Hawaii has grown at an average rate of about 0.02 km2/yr for the past 600 years.