Makatea Island, Tuamotu Archipelago, French Polynesia
Today we visited the island of Makatea, a raised coral atoll in the Tuamotus. Maketea, in Polynesian, means this kind of island and we have seen one more of these maketeas at Henderson Island early in our voyage. Charles Darwin, on his voyage through these waters on HMS Beagle, developed his theory of the formation of atolls as the end product of a process which begins with a volcanic island, like Easter Island or Pitcairn Island, emerging from the sea and, of course, there are thousands of these oceanic volcanoes in the Pacific. He envisioned that once the volcano becomes dormant a fringing reef develops all around the shore of the volcano. Then the volcano, no longer being pushed up by volcanic activity beneath it, begins to sink back down below sea level. But as long as it sinks slowly, the reef can grow upward all along its length. Eventually the fringing reef becomes a barrier reef and protects a lagoon with the remnants of the original volcanic island in the center as we saw at Mangareva. In Darwin’s final stage of development, the central island sinks beneath the waves and the barrier reef continues to grow upward forming an atoll as we have seen Raoia and Fakareva. He showed that large areas of the Pacific are characterized by a sinking seafloor and abundant atolls. Clearly at Maketea, and other makatea islands, another step has taken place, because here the entire atoll has been raised more than 200’ above sea level. Obviously the coral did not grow out of the sea and so the island had to have been pushed up carrying the atoll with it and forming the makatea. Thus, on this voyage we have seen the entire sequence which Darwin envisioned and even a final step which he did not—the makatea. And today we walked on the raised coral of the archtype, Makatea Island. No textbook, no photographic essay, nor any documentary film could match the experience which we have had of visiting, in person, all the stages, plus one, of Charles Darwin’s oceanic islands.
Today we visited the island of Makatea, a raised coral atoll in the Tuamotus. Maketea, in Polynesian, means this kind of island and we have seen one more of these maketeas at Henderson Island early in our voyage. Charles Darwin, on his voyage through these waters on HMS Beagle, developed his theory of the formation of atolls as the end product of a process which begins with a volcanic island, like Easter Island or Pitcairn Island, emerging from the sea and, of course, there are thousands of these oceanic volcanoes in the Pacific. He envisioned that once the volcano becomes dormant a fringing reef develops all around the shore of the volcano. Then the volcano, no longer being pushed up by volcanic activity beneath it, begins to sink back down below sea level. But as long as it sinks slowly, the reef can grow upward all along its length. Eventually the fringing reef becomes a barrier reef and protects a lagoon with the remnants of the original volcanic island in the center as we saw at Mangareva. In Darwin’s final stage of development, the central island sinks beneath the waves and the barrier reef continues to grow upward forming an atoll as we have seen Raoia and Fakareva. He showed that large areas of the Pacific are characterized by a sinking seafloor and abundant atolls. Clearly at Maketea, and other makatea islands, another step has taken place, because here the entire atoll has been raised more than 200’ above sea level. Obviously the coral did not grow out of the sea and so the island had to have been pushed up carrying the atoll with it and forming the makatea. Thus, on this voyage we have seen the entire sequence which Darwin envisioned and even a final step which he did not—the makatea. And today we walked on the raised coral of the archtype, Makatea Island. No textbook, no photographic essay, nor any documentary film could match the experience which we have had of visiting, in person, all the stages, plus one, of Charles Darwin’s oceanic islands.
