Great Barrier Reef Blue Hole Filmed For First Time Ever
December 12, 2017—Marine biologist Johnny Gaskell just explored a hidden hollow in the Great Barrier Reef of Australia. Called a blue hole, it formed during an ice age when the area's limestone floor was above water. When ocean levels again rose the site became a deeper patch of seafloor. In March 2017, a massive cyclone hit a section of the reef. But even in the cyclone's path, this blue hole survived.
