Loihi is the youngest volcano associated with the Hawaiian chain and is located 15 miles (28 km) southeast of Kilauea volcano. Earthquake swarms indicate that the volcano is active. The summit of the volcano is 3,178 feet (969 m) below sea level and contains a caldera-like depression. Two rift zones extend to the north and southeast. If Loihi erupts at rates comparable to Kilauea and Mauna Loa, it will reach sea level in a few tens of thousands of years. Map by U.S. Geological Survey.