HUSCAP logo Hokkaido Univ. logo

Hokkaido University Collection of Scholarly and Academic Papers >
理学院・理学研究院  >
雑誌発表論文等  >

Oxygen isotope systematics in Diploastrea heliopora: new coral archive of tropical paleoclimate

GCA_67_1439-.pdf574.24 kBPDF見る/開く

タイトル: Oxygen isotope systematics in Diploastrea heliopora: new coral archive of tropical paleoclimate
著者: Watanabe, Tsuyoshi 著作を一覧する
Gagan, Michael K. 著作を一覧する
Corrége, Thierry 著作を一覧する
Scott-Gagan, Heather 著作を一覧する
Cowley, Joan 著作を一覧する
Hantoro, Wahyoe S. 著作を一覧する
発行日: 2003年 4月 1日
出版者: Elsevier
誌名: Geochimica et Cosmochimica Acta
巻: 67
号: 7
開始ページ: 1349
終了ページ: 1358
出版社 DOI: 10.1016/S0016-7037(02)01221-8
抄録: Diploastrea heliopora forms dense, robust, dome-shaped coral colonies throughout the reef ecosystems of the tropical Pacific and Indian Oceans. This slow-growing (2 to 6 mm/yr) coral has the potential to yield continuous paleoclimate records spanning up to 1000 yr for the warmest waters on Earth, the Indo-Pacific Warm Pool, and has a long fossil history as a single recognizable species. Despite the potential of Diploastrea to be an important new paleoclimate archive, little is known about the systematics of geochemical tracers incorporated into its skeleton. To fill this knowledge gap, we compared skeletal δ18O signatures in live Diploastrea and Porites colonies from Southwest Lagoon, near Amédée Lighthouse, New Caledonia (at the southern latitudinal limit for Diploastrea) and Alor, Indonesia (in the core area of the Indo-Pacific Warm Pool). We designed a new microsampling technique to minimize smoothing and distortion of the isotopic records due to the complex calyx architecture and slow growth of Diploastrea. High-resolution isotope profiles from the septal portion of the Diploastrea corallite are attenuated, whereas those restricted to the central columella are similar in quality to those extracted from the well-established Porites coral archive. The δ18O-temperature relationship for the columellar portion of Diploastrea (−0.18‰/°C) is in good agreement with that derived for a nearby Porites (−0.19‰/°C; Quinn et al., 1996), on the basis of comparison with an in situ sea surface temperature record from Amédée Lighthouse. There is a measurable difference of 0.3 ± 0.1‰ between the kinetic/biological disequilibrium offsets from seawater δ18O composition for Diploastrea and Porites. Despite this offset in mean δ18O, Diploastrea accurately records the regional differences in mean temperature and salinity between New Caledonia and the Indo-Pacific Warm Pool. Additional tests show that Diploastrea records El Niño–Southern Oscillation (ENSO) interannual variability in sea surface temperature and salinity across the southwestern Pacific, indicating that it should yield dependable paleo-ENSO records. Based on these results, we propose that D. heliopora has the potential to provide an important new coral archive of tropical paleoclimate.
資料タイプ: article (author version)
出現コレクション:雑誌発表論文等 (Peer-reviewed Journal Articles, etc)

提供者: 渡邊 剛


本サイトに関するご意見・お問い合わせは repo at へお願いします。 - 北海道大学