HOT SPOTS!

The vast majority of earthquakes and volcanic eruptions occur near plate boundaries, but there are a few exceptions. The Hawaiian Islands, made entirely of volcanic rock, have formed in the middle of the Pacific Ocean more than 3,200 km from the nearest plate boundary. Areas like the Hawaiian Islands are referred to as “hot spots.” In certain locations around the world, volcanos has been active for very long periods of time. This happens when small, long-lasting, and exceptionally hot regions, called hotspots, exist below the plates that provide sources of high heat energy to sustain volcanism. The Hawaiian Island chain resulted from the Pacific Plate moving over a deep, stationary hotspot in the mantle, located beneath the present-day position of the Island of Hawaii. Heat from this hotspot produced a steady source of magma by partly melting the overriding Pacific Plate. The magma, which is lighter than the surrounding solid rock, then rises through the mantle and crust to erupt onto the seafloor to form an active seamount. Over time, countless eruptions cause the seamount to grow until it finally emerges above sea level to form an island volcano. Continuing plate movement eventually carries the island beyond the hotspot, cutting it off from the magma source, and it is not longer active. As one island volcano becomes extinct, another develops over the hotspot, and the cycle is repeated.