by Yasufumi Iryu, Hiroki Matsuda, Werner Erwin Piller, Terrence M. Quinn, Maria Mutti

Coral reefs are tropical to subtropical, coastal ecosystems comprising very diverse organisms. Late Quaternary reef deposits are fossil archives of environmental, tectonic, and eustatic variations that can be used to reconstruct the paleoclimatic and paleoceanographic history of the tropical surface oceans. Reefs located at the latitudinal limits of coral reef ecosystems (i.e., those at coral-reef fronts) are particularly sensitive to environmental changes; especially those associated with glacial-interglacial changes in climate and sea level. We propose a scientific drilling campaign in the Ryukyu Islands (= the Ryukyus) in the northwestern Pacific Ocean to investigate the dynamic response of the corals and coral reef ecosystems in this region to Quaternary climate and sea level change. Such a drilling campaign, which we call the COREF (coral-reef front) Project, will allow the following two major questions to be evaluated: (1) What is the response of the coral-reef ecosystems to Holocene sea-level rise? This projects aims at collecting Holocene reef sequences across a spectrum of latitudes, from the northernmost to the southernmost sites, to characterize the response of reef ecosystems to the Holocene sea-level rise along the latitudinal gradient. (2) What is the response of the coral-reef ecosystems to previous high stands of sea level and associated warm intervals of the mid-Pleistocene. Examining mid-Pleistocene coral reef communities across the same latitudinal spectrum will provide information on how these responded to warmer episodes in the past and hence provide valuable information on how future migrations of the coral reef front may occur as a consequence of ongoing global warming. The geographic, climatic and oceanographic setting of the Ryukyu Islands provide an ideal natural laboratory to address each of these research questions. To resolve the problems described above, the Ryukyu Islands are one of the best fields.

• Major scientific objectives of this project are to examine the following questions:
• (1) What is the response of the coral-reef ecosystems of the Ryukyus to Holocene sea- level rise? This projects aims at collecting Holocene reef sequences across a spectrum of latitudes, from the northernmost to the southernmost sites, to characterize the response of reef ecosystems to the Holocene sea-level rise along the latitudinal gradient.
• (2) What is the response of the coral-reef ecosystems of the Ryukyus to previous high stands of sea level and associated warm intervals of the mid-Pleistocene (= latest early to middle Pleistocene time between 0.41 Ma and 0.85 Ma)? Examining mid-Pleistocene coral reef communities across the same latitudinal spectrum will provide information on how these responded to warmer episodes in the past and hence provide valuable information on how future migrations of the coral reef front may occur as a consequence of ongoing global warming.

Climate Change, Coral Reef Drilling, COREF, Geobiosphere, Global Environment, ICDP-2010/02, Paleoclimatology, Quaternary, Ryukyu Islands, Sea-Level Changes

Latitude: 30.42531, Longitude: 130.97264