A major submerged terrace whose seaward edge is at about 150 m depth was investigated in 1983 during 10 dives with the Hawaii Undersea Research Laboratory (HURL) submersible Makali'i off Kealakekua Bay, Hawaii. The seaward termination of the terrace is a steep wall of reef limestone that extends from 150 to 250 m below sea level. Three samples of limestone collected from the reef face at depths of 204-219 m yield a weighted average 14C age of 13 250 yr BP. The best fit of depth, age, and subsidence data indicates that the northwestern coast of Hawaii has subsided at an absolute rate of 1.8 to 3+ mm/yr and that the rate of subsidence has generally increased over the past 0.3 Myr. Each reef terrace grew intermittently for nearly 0.1 Myr: the -150 m reef terrace was drowned about 13 000 yr BP, the -390 m terrace about 145 000 yr BP, and the -580 m terrace about 255 000 yr BP. -from Authors
Additional Publication Details
Drowned reefs as indicators of the rate of subsidence of the Island of Hawaii.