Explorers of the Great Barrier Reef have discovered a giant pinnacle of coral.
This week, a team of scientists reported finding a detached coral feature that rises from the seabed to a height of nearly one-third of a mile — taller than the Empire State Building. Its discoverers call it the first large new element of Australia’s famous reef system to be identified in more than 120 years.
Moreover, the new reef is flourishing, in contrast to many ill ones in the Great Barrier and around the globe. Corals in warm, polluted waters often suffer environmental stresses that can turn them white and, if prolonged, kill them off. The wastage is known as coral bleaching.
“It was a good day” when the team brought the massive new reef to light for the first time, said Robin Beaman of James Cook University, the expedition’s chief scientist.
The discovery was made aboard a joint research expedition of Australian scientists and the Schmidt Ocean Institute, based in Palo Alto, Calif. Founded by Eric Schmidt, the former chairman of Google, and his wife, Wendy, the institute lets scientists use its research vessel, the Falkor, at no cost. Nearly the length of a football field, the ship can map the remote seabed with beams of sound and lower tethered and autonomous robots that capture close-up images of the unexplored depths.
Already this year, the Australian team has used the ship to probe the Coral Sea, finding odd features and life-forms, as well as the inky depths off Western Australia. There it stumbled on a coiling gelatinous creature estimated at 150 feet in length, potentially the world’s longest example of marine life.
Viewed from afar, the Great Barrier Reef seems like a single giant structure of coral outcroppings. It is the world’s largest reef system, running along the northeastern coast of Australia for more than 1,500 miles, and has generated much concern because its shallower parts have bleached repeatedly. But it is not continuous. Instead, it is comprised of hundreds of islands and thousands of individual reefs — some ringing the isles, some free-standing, some forming long ribbons that parallel the coastline.
The new discovery lies in the northern part of the reef roughly 60 miles from the Cape York Peninsula, a wilderness area in Australia’s far north that has few towns, ports or tourists. That makes its nearby reefs relatively difficult to visit and explore.
Even so, mariners long ago charted seven pinnacle reefs off the cape that, by definition, lie apart from the main barrier system. Bathed in clear waters, the detached reefs swarm with sponges, corals and brightly colored fish — as well as sharks — and are oases for migrating sea life. Their remoteness makes the pinnacles little-studied, and Australia’s Great Barrier Reef Marine Park Authority has assigned them its highest levels of protection, which limit such activities as commercial fishing. One detached reef at Raine Island is the world’s most important nesting area for green sea turtles.
The new pinnacle was found a mile and a half from a known detached reef. Dr. Beaman, who formerly served in the Royal Australian Navy as a hydrographic surveyor, said he and his team were certain it was previously unknown. Its seven relatives, he added, were all charted in the 1880s, more than 120 years ago.
He said the team first glimpsed the new pinnacle on Oct. 19 and mapped it the next day with sound beams that detailed its deep contours. “We could see it in 3-D,” he said. The team then conducted an exploratory dive on Oct. 25 with the underwater robot, livestreaming close-up images on the Schmidt institute’s website and YouTube channel.
“It was thrilling,” Dr. Beaman said of the summit’s riot of life. “There were sharks everywhere, three different kinds.” The dive found not only hosts of fish and corals but the shells of chambered nautiluses — a living fossil whose ancestors go back a half-billion years.
Dr. Beaman said the reef’s limestone base is roughly a mile wide and the summit rises more than 1,690 feet, about 130 feet shy of the sea’s surface.
The pinnacles are ancient, he said, having grown slowly over millions of years to their current heights. Dr. Beaman said it happened as the seabed receded in step with Australia’s rocky footings moving downward over geologic time in a process known as continental drift. In response, the corals kept building new layers so their symbiotic algae would be close enough to the surface to tap sunlight for photosynthesis.
“They grow from the top down,” he said of the pinnacles. “They keep clinging to this living zone.” Dr. Beaman added that the expedition had found hundreds of small peaks that failed to make enough new layers, which are known as drowned reefs.
“This one has managed to stay alive and is still growing,” he said of the newly discovered reef. “Corals are so simple. But they build these incredible structures.”