DICASE

Type Oceanographic cruise
Ship Téthys II
Ship owner CNRS until 2019 - IFREMER since 2020
Dates 02/06/2014 - 11/06/2014
Chief scientist(s) LANSARD Bruno ORCID

LABORATOIRE DES SCIENCES DU CLIMAT ET DE L'ENVIRONNEMENT - UMR 8212

Orme des Merisiers

Bâtiment 714

Chemin de Saint Aubin - RD 128

91191 Gif sur Yvette Cedex

+33(0)1 69 08 77 11

contact@lsce.ipsl.fr

https://www.lsce.ipsl.fr/

DOI 10.17600/14007100
Objective

The DICASE cruise looked at the spatial variability of benthic recycling of organic matter and its interactions with carbonates. So it focused on organic and inorganic carbon dynamics at the interface between bottom water and sediments and provided some elements of response about the spatial variability of CO2 fluxes at the water-sediment interface. In sediments, organic carbon is mainly mineralized, whereas carbonates are either preserved or dissolved depending on the sediments' pH. Therefore the amount of carbon stored in sediments depends on the rate at which terrigenous and marine organic matter is deposited, on the intensity of organic carbon recycling and on the pH conditions. The cruise provided an initial integrated study of carbonate dissolution in Rhone delta sediments by measuring pH profiles in situ and ex situ, total alkalinity, DIC, Ca2+ and Mg2+ in order to highlight any dissolution of carbonates in these sediments. The related project is MERMEX.

Scientific context

Main results

Data acquired and analyses carried out at sea and on shore

Data managed by SISMER

Bibliography

Publications

Dumoulin J-P, Pozzato L., Rassman J., Toussaint F., Fontugne M., Tisnerat-Laborde N., Beck L., Caffy I., Delque-Kolic E., Moreau C., Rabouille C. (2018). Isotopic Signature (δ13C, ∆14C) of DIC in Sediment Pore Waters: An Example from the Rhone River Delta. Radiocarbon, 60(5), 1465-1481. Publisher's official version : https://doi.org/10.1017/RDC.2018.111 , Open Access version : https://archimer.ifremer.fr/doc/00724/83636/


Pozzato Lara, Rassmann Jens, Lansard Bruno, Dumoulin Jean-Pascal, Van Breugel Peter, Rabouille Christophe (2018). Origin of remineralized organic matter in sediments from the Rhone River prodelta (NW Mediterranean) traced by Delta C-14 and delta C-13 signatures of pore water DIC. Progress In Oceanography, 163, 112-122. https://doi.org/10.1016/j.pocean.2017.05.008


Rassmann Jens, Lansard Bruno, Pozzato Lara, Rabouille Christophe (2016). Carbonate chemistry in sediment porewaters of the Rhône River delta driven by early diagenesis (northwestern Mediterranean). Biogeosciences, 13(18), 5379-5394. Publisher's official version : https://doi.org/10.5194/bg-13-5379-2016 , Open Access version : https://archimer.ifremer.fr/doc/00354/46505/


References of International Seminar Communications

Rabouille C, Pozzato L, Toussaint F, Cathalot C, Rassmann J, Lansard B, Laborde N, Moriarty J and C Harris (2017). Origin of organic matter and temporal variability of carbon recycling in deltaic sediments at different time scales: an example in the Rhône River Delta, 14th International Estuarine Biogeochemistry Symposium (IEBS), 04-07/06/17, Rimouski, Canada.

Rassmann J, Eitel E, Cathalot C, Brandily C, Lansard B, Taillefert M and C Rabouille (2017). Benthic fluxes indicating uncoupled aerobic and anaerobic processes in the Rhône River prodelta, 27th Goldschmidt Conference, 13-18/08/17, Paris, France.

Rassmann R, Rabouille C, Taillefert M, Eitel E, Bombled B, Pozzato L and B Lansard (2017). Alkalinity fluxes across the sediment-water interface from anoxic sediments in the Rhône River Delta (NW Mediterranean), 14th International Estuarine Biogeochemistry Symposium (IEBS) 04-07/06/17, Rimouski, Canada.

Rassmann J, Rabouille C, Taillefert M, Eitel E, Bombled B and B Lansard (2016). Quantifying chemical fluxes across the sediment-water interface and their impact on the carbonate system: A case study at the Rhône River mouth (NW Mediterranean), 17-22/04/2016, EGU 2016, Vienna, Austria.

Rassmann J, Rabouille C, Toussaint F, Cathalot C, Tisnerat-Laborde N and B Lansard (2016). Carbon recycling in deltaic sediments: variations at different timescales in the Rhone River delta. Ocean Sciences Meeting, 21-26/02/16, New Orleans, USA.

References of National Seminar Communications

Rassmann J, Rabouille C, Toussaint F, Cathalot C, Abchiche A, Aouji O, Buchholtz G, Tisnérat-Laborde N and B Lansard (2016). Observing oxygen dynamics and carbon recycling in deltaic sediments at different timescales using in situ methods: an example from the Rhone River delta. 25ème Réunion des Sciences de la Terre, 24-28/10/16, Caen, France.

Rassmann J., Rabouille C., Lansard B., Pozzato L., Bombled B. et J.-P. Dumoulin (2015). Le système des carbonates à l'interface eau-sédiment forcé par la diagenèse précoce : cas du prodelta du Rhône. 3ème colloque de la Flotte Océanographique Française, 11-12/06/15, Bordeaux.

Thesis using campaign data

Rassmann Jens (2016). Le système des carbonates influencé par la diagenèse précoce dans les sédiments côtiers méditerranéens en lien avec l’acidification des océans / The carbonate system driven by early diagenesis in Mediterranean coastal sediments in relation to ocean acidification. PhD Thesis, Université Paris saclay. https://archimer.ifremer.fr/doc/00659/77076/