High Caribbean Reconstructed Haase-Schramm

Core/Site name:

Montego Bay and Pedro Bank

Country/Region:

Jamaica

Elevation:

-20 and -125

Archive:

corals

Species:

Ceratoporella nicholsoni

Proxy measurement:

Sr/Ca

Sampling resolution:

decadal

Climate sensitivity:

mixed layer & thermocline temperature

Dating resolution:

greater than 10

Dating information:

radiometric (U-Th, PB19, 14C)

Startyear:

1344 AD

Endyear:

1992 AD

All uncertainties:

"External precision (2sd) for d18O is ±0.07‰ (PDB)based on multiple analyses (n=87) of standards NBS 19 and IAEA CO1""

Description:

""The externalreproducibility (2sd) of the Sr/Ca ratios was determined to be 1.5% from repeatedmeasurements (n=123) of the in-house aragonite standard ""Ce96-4’""""

Data entered by name:

""The external reproducibility of our U/Th dating resultswas determined as about ±20 years (2sem)""

Data entered by email:

radiocarbon age ""Precision is better than ±30 conventional radiocarbon years."""

Main reference(s):

We investigate aragonitic skeletons of the Caribbean sclerosponge Ceratoporella nicholsoni from Jamaica, 20 m below sea level (mbsl), and Pedro Bank, 125 mbsl. We use d18O and Sr/Ca ratios as temperature proxies to reconstruct the Caribbean mixed layer and thermocline temperature history since 1400 A.D. with a decadal time resolution. Our age models are based on U/Th dating and locating of the radiocarbon bomb spike. The modern temperature difference between the two sites is used to tentatively calibrate the C. nicholsoni Sr/Ca thermometer. The resulting calibration points to a temperature sensitivity of Sr/Ca in C. nicholsoni aragonite of about -0.1 mmol/mol/K. Our Sr/Ca records reveal a pronounced warming from the early 19th to the late 20th century, both at 20 and 125 mbsl. Two temperature minima in the shallow water record during the late 17th and early 19th century correspond to the Maunder and Dalton sunspot minima, respectively. Another major cooling occurred in the late 16th century and is not correlatable with a sunspot minimum. The temperature contrast between the two sites decreased from the 14th century to a minimum in the late 17th century and subsequently increased to modern values in the early 19th century. This is interpreted as a long-term deepening and subsequent shoaling of the Caribbean thermocline. The major trends of the Sr/Ca records are reproduced in both specimens but hardly reflected in the d18O records.

Link to reference 1:

Giri Kattel / Helen McGregor

Link to reference 2:

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Data storage link 1:

Haase-Schramm, A., F. Böhm, A. Eisenhauer, W.C. Dullo, M.M. Joachimski, B. Hansen, and J. Reitner. 2003. Sr/Ca ratios and oxygen isotopes from sclerosponges: Temperature history of the Caribbean mixed layer and thermocline during the Little Ice Age. Paleoceanography 18(3):1073.

Data storage link 2:

http://www.boehmf.de/Haase_et_al.pdf

Comments:

http://www.agu.org/pubs/crossref/2003/2002PA000830.shtml

Category: Ocean2k