High Pacific native Wörheide

Core/Site name:

Great Barrier Reef


Queensland, Australia






Astrosclera willeyana

Proxy measurement:

o18 c13

Sampling resolution:


Climate sensitivity:

temperature, salinity, industrialization CO2

Dating resolution:


Dating information:



1552 AD


1990 AD


Stable Isotope Data from the sclerosponge Astrosclera willeyana,collected at Ribbon Reef #10, Great Barrier Reef, Queensland, Australia 14 40' 70" S, 145 40' 90"" E, 23m water depth.Stable isotope time series (46 samples) of delta18O and delta13C were measured in successive growth layers of the large Astrosclera from Ribbon Reef #10 (GBR).Astrosclera forms its skeletal aragonite in equilibrium with the ambient seawater, and represents, therefore, a high precision recorder of the isotopic history of the ambient seawater.Delta13C of surface water dissolved inorganic carbon in the northern Great Barrier Reef has apparently decreased continuously since the mid-16th century. The total decrease is 0.7 per mill.The major decline of 0.5 per mill. occurred during the industrial period of the 19th and 20th century, likely to be due to the increased release of CO2 by deforestation and burning of fossil fuel during the period of industrialization after 1850 (increased input of lighter carbon isotopes).The oxygen isotope history shows a slightly colder (and/or dryer) phase before 1850, which correlates with the Little Ice Age. A considerable shift to lighter values occurred during the 20th century (warming of SST). This may be due to an anthropogenic greenhouse effect. Most of the major climatic changes caused by ENSO/El Niño events as well as by large volcanic eruptions in the last four and a half centuries were recorded in the oxygen isotope record of Astrosclera."

Data entered by name:

Saenger, Casey

Data entered by email:

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Main reference(s):

Wörheide, G., 1998. The reef cave dwelling ultraconservative coralline demosponge Astrosclera willeyana Lister 1900 from the Indo-Pacific. Micromorphology, ultrastructure, biocalcification, isotope record, taxonomy, biogeography, phylogeny. Facies, 38: 1-88.

Link to reference 1:


Data storage link 1:



Age model assumes constant growth rate

Current dating method:

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Annual snow acc rate:

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Category: Ocean2k