Reef Carbonate Productivity During Quaternary Sea Level Oscillations

Type Article
Date 2018-04
Language English
Author(s) Husson L.1, Pastier A. -M.2, Pedoja K.3, Elliot M.4, Paillard D.5, Authemayou C.6, Sarr A. -C.1, Schmitt A.4, Cahyarini S. Y.7
Affiliation(s) 1 : Univ Grenoble Alpes, CNRS, ISTerre, Grenoble, France.
2 : Univ Rennes 1, CNRS, Geosci Rennes, Rennes, France.
3 : Univ Caen, CNRS, Caen M2C, Caen, France.
4 : Univ Nantes, CNRS, LPG Nantes, Nantes, France.
5 : CEA, CNRS, LSCE, Gif Sur Yvette, France.
6 : Univ Brest, CNRS, LGO, IUEM, Plouzane, France.
7 : Indonesian Inst Sci, LIPI, Res Ctr Geotechnol, Bandung, Indonesia.
Source Geochemistry Geophysics Geosystems (1525-2027) (Amer Geophysical Union), 2018-04 , Vol. 19 , N. 4 , P. 1148-1164
DOI 10.1002/2017GC007335
WOS© Times Cited 9
Keyword(s) coral reefs, sea level, carbonate, modeling, paleoclimate
Abstract

Global variations in reef productivity during the Quaternary depend on external parameters that may alter the global chemical balance in the oceans and atmosphere. We designed a numerical model that simulates reef growth, erosion, and sedimentation on coastlines undergoing sea level oscillations, and uplift or subsidence. We further develop a probabilistic evaluation that accounts for variable vertical ground motion, erosion, and foundation morphologies. Absolute sea level change appears primordial, as productivity must have increased by an order of magnitude since the onset of the glacial cycles, approximate to 2.6 Ma. But most important is relative sea level change, i.e., eustasy modulated by uplift or subsidence, that rejuvenates the accommodation space and exposes pristine domains of the shore to active reefs at each cycle. Integrated over the long-term, vertical land motion sets the pace of reef growth: productivity in tectonically unstable domains is thus expected to be up to 10 times higher than in stable regions, if any. We quantify the global length of reef coasts and the probability density functions for slopes and uplift rates. Productivity waxes during transgressions to reach 2-8 GtCaCO3/yr and wanes during highstands, which may contribute to increase atmospheric pCO(2) by several tens of ppm during deglaciations. Over the last 1.5 Ma, reefs precipitated approximate to 0.8 x 10(6) GtCaCO3 (approximate to 500 x 10(3) km(3)), the equivalent of a 1 m-thick layer spread over the entire surface of the Earth. This production modulates the calcium budget, for it represents some 30% of the modern Ca flux in the ocean.

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How to cite 

Husson L., Pastier A. -M., Pedoja K., Elliot M., Paillard D., Authemayou C., Sarr A. -C., Schmitt A., Cahyarini S. Y. (2018). Reef Carbonate Productivity During Quaternary Sea Level Oscillations. Geochemistry Geophysics Geosystems, 19(4), 1148-1164. Publisher's official version : https://doi.org/10.1002/2017GC007335 , Open Access version : https://archimer.ifremer.fr/doc/00638/74993/