Stable carbon isotope record of planktonic foraminifera and organic matter from sediment cores in the Gulf of Aqaba

The high sedimentation rates at the core sites (about 54 cm/Kyear) provide high temporal resolution (~10 years). Recent sediments at the top of the cores reflect conditions younger than 1950.

The delta13C records of the planktonic foraminifera from three multicores display similar trends, showing a uniform and consistent pattern before the 1750s, and a gradual decrease of approximately 0.63 per mil over the last two centuries. This decrease seems to track the decrease of delta13CDIC in surface waters, which is mainly caused by the increase of anthropogenic input of 13C-depleted CO2 into the atmosphere. Similarly, a trend towards lighter values of the carbon isotopic composition of sedimentary organic matter (delta13Corg) during the last 200 years supports the interpretation obtained from the planktonic foraminiferal delta13C.