Mauna Kea is an inactive volcano on the island of Hawaiʻi. Its peak is 4,207.3 m above sea level, making it the highest point in the state of Hawaii and second-highest peak of an island on Earth. The peak is about 38 m higher than Mauna Loa, its more massive neighbor. Mauna Kea is unusually topographically prominent for its height: its wet prominence is fifteenth in the world among mountains, at 4,205 m; its dry prominence is 9,330 m. This dry prominence is greater than Mount Everest's height above sea level of 8,848.86 m, and some authorities have labeled Mauna Kea the tallest mountain in the world, from its underwater base.