Tallest mountain

Mauna Kea (White Mountain) on the island of Hawaii, USA, is the world's tallest mountain. Measured from its submarine base in the Hawaiian Trough to its peak, it has a combined height of approximately 10,205 metres (33,480 feet) of which 4,205 metres (13,796 feet) are above sea level.

There is some debate as to precisely where the base of Mauna Kea should be considered to begin. While most of the sea floor is between 2,500 and 3,000 fathoms (4,572–5,486 m) off the island's northern and eastern shores, and between 2,000 and 2,500 fathoms (3,657–4,572 m) to the south and west, the deepest point in the local region is a small trough called the Hawaiian Deep/Trough – "a depression of the surrounding oceanic plate as a consequence of loading by volcanoes of the island of Hawaii, including Mauna Kea". In this depression, the sea floor plunges to some 3,200–3,280 fathoms (5,500–6,000 m), which is how we reached our total height for Mauna Kea.