High Pacific native Lough

Core/Site name:

Multiple

Country/Region:

Great Barrier Reef, Australia

Archive:

corals

Proxy measurement:

Extension rate, Density, Calcification

Sampling resolution:

annual

Climate sensitivity:

Biological Processes

Dating resolution:

Annual

Startyear:

1479 AD

Endyear:

1991 AD

All uncertainties:

2-3 year dating uncertainty.

Description:

Great Barrier Reef Coral Extension, Density, and Calcification data from 60 Porites coral cores covering the entire length of the Great Barrier Reef, Australia. Data set contains extension (cm/yr), density (g/cm3), and calcification (g/cm2/yr) from 60 individual cores.The Australian Institute of Marine Science began collecting cores from very large massive colonies of Porites on the Great Barrier Reef in the early 1980s. Such cores cannot normally be identified to species. The cores were mounted and sawn to remove slices that were about 6-7mm thick. All slices were X-rayed and skeletal density measured along a central track on each slice using a gamma densitometer. The high density portion of annual density bands in Porites from the Great Barrier Reef appears to form usually between October and March, the Southern Hemisphere summer. Peaks in the density profiles were successively counted backwards from the last (outermost or youngest) peak. Density was assumed to peak in January and the most recent peak was dated from the date of collection of the core. Dates were then assigned to all peaks in the series. Time series of the following skeletal growth parameters were then obtained:1) Average annual density (g.cm-3)2) Annual linear extension measured between low density troughs (cm.yr-1)3) Annual calcification (g.cm-2.yr-1); the product of annual average density and annual linear extensionThese data were obtained from 60 coral cores taken from 39 sites on the Great Barrier Reef. The density profiles do not always display regular, obvious annual peaks and we could not be absolutely sure of the dating for some profiles. We consider there may be errors of + or - 2-3 years in the starting date of some of these series.This data set replaces IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2001-024 previously lodged with NOAA Paleoclimatology Data Center. It includes measurements from an expanded range of coral cores and remeasuring and redating of all old and new material. The new measurements included simultaneous measurements of coral luminescence (not included in the data set) which allowed for improved chronological control. The earlier data set was also based on annual extension being measured between adjacent density maxima whereas the new data set is based on linear extension being measured between adjacent density minima.

Data entered by name:

Thirumalai, Kaustubh

Data entered by email:

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Main reference(s):

De'ath, G., J.M. Lough, and K.E. Fabricius. 2009. Declining coral calcification on the Great Barrier Reef. Science, Vol. 323, pp. 116 - 119, 2 January 2009.Lough, J.M. and D.J. Barnes, 2000. Environmental controls on growth of the massive coral Porites. Journal of Experimental Marine Biology and Ecology, 245: 225-243.Lough, J.M. and D.J. Barnes, 1997. Several centuries of variation in skeletal extension, density and calcification in massive Porites colonies from the Great Barrier Reef: a proxy for seawater temperature and a background of variability against which to identify unnatural change. Journal of Experimental Marine Biology and Ecology, 211: 29-67.Chalker, B.E. and D.J. Barnes, 1990. Gamma densitometry for the measurement of coral skeletal density. Coral Reefs, 4: 95-100.

Data storage link 1:

http://hurricane.ncdc.noaa.gov/pls/paleox/f?p=519:1:3013599921808672::::P1_STUDY_ID:1863

Data storage link 2:

ftp://ftp.ncdc.noaa.gov/pub/data/paleo/coral/west_pacific/great_barrier/readme_greatbarrier.txt

Current dating method:

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Annual snow acc rate:

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Category: Ocean2k