TY - JOUR
T1 - Examining water temperature proxies in Porites corals from the Great Barrier Reef
T2 - A cross-shelf comparison
AU - Fallon, Stewart J.
AU - McCulloch, Malcolm T.
AU - Alibert, Chantal
PY - 2003/12
Y1 - 2003/12
N2 - Cores from colonies of the coral species Porites sp. were collected from inshore, mid-shelf, and outer reef localities (central Great Barrier Reef) to test the robustness of the major elemental sea surface temperature (SST) proxies (B/Ca, Mg/Ca, Sr/Ca, U/Ca) to the influence of inshore processes. Time series analyses of Sr/Ca, U/Ca, B/Ca, and Mg/Ca are compared to sea surface temperature (SST) in order to provide calibrations for these elements. This study shows that there are significant variations between the corals with respect to some of the proxies. In some cases, variations of ∼6°C are observed for a single U/Ca value. This magnitude of variation is also seen in the Mg/Ca proxy and, to a smaller extent, in the B/Ca-SST relationship. In two of the corals, both Mg/Ca and U/Ca do not follow a seasonal signal. The Mg/Ca and U/Ca ratios for two inshore corals are significantly different than the offshore corals (lower and higher, respectively). The other two proxies (B/Ca and Sr/Ca) do not display any inshore vs. offshore variations except for one inshore site that did not have a clear seasonal signal for either of these proxies. The Sr/Ca-SST relationship is the most robust, with a temperature variation of ∼2°C for a single Sr/Ca value, which is within error for this technique.
AB - Cores from colonies of the coral species Porites sp. were collected from inshore, mid-shelf, and outer reef localities (central Great Barrier Reef) to test the robustness of the major elemental sea surface temperature (SST) proxies (B/Ca, Mg/Ca, Sr/Ca, U/Ca) to the influence of inshore processes. Time series analyses of Sr/Ca, U/Ca, B/Ca, and Mg/Ca are compared to sea surface temperature (SST) in order to provide calibrations for these elements. This study shows that there are significant variations between the corals with respect to some of the proxies. In some cases, variations of ∼6°C are observed for a single U/Ca value. This magnitude of variation is also seen in the Mg/Ca proxy and, to a smaller extent, in the B/Ca-SST relationship. In two of the corals, both Mg/Ca and U/Ca do not follow a seasonal signal. The Mg/Ca and U/Ca ratios for two inshore corals are significantly different than the offshore corals (lower and higher, respectively). The other two proxies (B/Ca and Sr/Ca) do not display any inshore vs. offshore variations except for one inshore site that did not have a clear seasonal signal for either of these proxies. The Sr/Ca-SST relationship is the most robust, with a temperature variation of ∼2°C for a single Sr/Ca value, which is within error for this technique.
UR - http://www.scopus.com/inward/record.url?scp=0347028378&partnerID=8YFLogxK
U2 - 10.1007/s00338-003-0322-5
DO - 10.1007/s00338-003-0322-5
M3 - Article
SN - 0722-4028
VL - 22
SP - 389
EP - 404
JO - Coral Reefs
JF - Coral Reefs
IS - 4
ER -