Sr/Ca ratios and oxygen isotopes from sclerosponges: Temperature history of the Caribbean mixed layer and thermocline during the Little Ice Age

Haase A, Böhm F, Eisenhauer A, Dullo WC, Joachimski M, Hansen B, Reitner J, Schramm A (2003)

Publication Status: Published

Publication Type: Journal article, Original article

Publication year: 2003

Journal

Paleoceanography American Geophysical Union (AGU) / Wiley

Publisher: Agu American Geophysical Union

Book Volume: 18

Pages Range: 18-1

Journal Issue: 3

DOI: 10.1029/2002PA000830

Abstract

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 SO 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 warning from the early 19th to the late 20th century, both at 20 and 125 mbsl. Two temperature minima in the shallow water records 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 SO records.

Authors with CRIS profile

Alexandra Haase
Michael Joachimski Lehrstuhl für Geologie (Exogene Dynamik)

Involved external institutions

Max-Planck-Institut für Chemie (Otto Hahn Institut) / Max Planck Institute for Chemistry DE Germany (DE) GEOMAR Helmholtz-Zentrum für Ozeanforschung Kiel DE Germany (DE) Georg-August-Universität Göttingen DE Germany (DE)

How to cite

APA:

Haase, A., Böhm, F., Eisenhauer, A., Dullo, W.-C., Joachimski, M., Hansen, B.,... Schramm, A. (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), 18-1. https://dx.doi.org/10.1029/2002PA000830

MLA:

Haase, Alexandra, et al. "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 (2003): 18-1.

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