Mauna Kea is a dormant shield volcano on the island of Hawaiʻi. Its peak is 4,207.3 m (13,803 ft) above sea level, making it the highest point in Hawaii and the island with the second highest high point, behind New Guinea. The peak is about 38 m (125 ft) higher than Mauna Loa, its more massive neighbor. Mauna Kea is unusually topographically prominent for its height: its prominence from sea level is 15th in the world among mountains, at 4,207.3 m (13,803 ft); its prominence from under the ocean is 9,330 m (30,610 ft), rivaled only by Mount Everest. This dry prominence is greater than Everest's height above sea level of 8,848.86 m (29,032 ft), and some authorities have labeled Mauna Kea the tallest mountain in the world, from its underwater base. Mauna Kea is ranked 8th by topographic isolation.