Radiocarbon Reservoir Ages in the Mediterranean Sea and Black Sea

Abstract

We measured apparent marine radiocarbon ages for the Mediterranean Sea, Black Sea, and Red Sea by accelerator mass spectrometry radiocarbon analyses of 26 modern, pre-bomb mollusk shells collected living between AD 1837 and 1950. The marine reservoir (R(t)) ages were estimated at some 390 ± 85 yr BP, 415 ± 90 yr BP and 440 ± 40 yr BP, respectively. R(t) ages in the Mediterranean Sea and Black Sea are comparable to those for the North Atlantic Ocean (<65°N), in accordance with the modern oceanic circulation pattern. The ΔR values of about 35 ± 70 yr and 75 ± 60 yr in the Mediterranean area show that the global box-diffusion carbon model, used to calculate R(t) ages, reproduces the measured marine 14C R(t) ages in these oceanic areas. Nevertheless, high values of standard deviations, larger than measurement uncertainties are obtained and express decadal R(t) changes. Such large standard deviations are indeed related to a decrease of the apparent marine ages of some 220 yr from 1900 AD to 1930 AD in both the Mediterranean Sea and the western North Atlantic Ocean.

Holocene Variations of Radiocarbon Reservoir Ages in a Mediterranean Lagoonal System

“…14 C ages were also obtained on a series of Holocene mollusk shells sampled at different depths of the ~8-m-long core PB06. Careful examination of the 14 C ages versus depth relationships suggests that R(t) in the past was lower and similar to the value presently measured in the Gulf of Lion (618 ± 30 14 C yr, Siani et al 2000). The change in R(t) from 618 to 943 yr is thought to result from final closure of the coastal lagoon by the sandy barrier, due to the along-shore sediment transfer.…”

“…For the central part of the Gulf of Lion, Siani et al (2000) found a higher R estimated at 245 ± 30 yr (R(t)  618 ± 30 14 C yr), which is the average of 3 samples collected at Sète and Banyuls and recalculated by using the calibration model of Hughen et al (2004). This offset from the Marine04 model has been explained as a result of biological processes or hardwater effects due to the discharge of coastal rivers after dissolution of limestone via several brackish lagoons, before reaching this part of the Mediterranean Sea.…”

Growth and demise of cold-water coral ecosystems on mud volcanoes in the West Alboran Sea: The messages from the planktonic and benthic foraminifera

“…The chronology of the two cores retrieved from Dhaka and Maya MVs (TTR17-MS411G and TTR17-MS419G, respectively) is based on 8 AMS 14 C ages ( (Siani et al, 2000) was subtracted to the obtained radiocarbon conventional ages, which were calibrated using the program Calib 5.1 (Stuiver and Reimer, 1993).…”

“…Calibration using the software Calib 5.1 (Stuiver and Reimer, 1993). A reservoir effect of 400 years was subtracted (Siani et al, 2000). G. inflata increases from 45 cm upwards to over 30% in the upper part of the core with a negative peak (10%) at 35 cm.…”

Differences between the last two glacial maxima and implications for ice-sheet, δ18O, and sea-level reconstructions

“…PGM/MIS 6: Astakhov, 2011Astakhov et al, 2016;Ehlers et al, 2011a, b;Gurski et al, 1990;Mohr, 1993;Rose, 2009;Rose et al, 2002, Ruzicka, 2004Velichko et al, 2011. 2003a,b). d 18 O records include data for the surface-dwelling planktonic foraminifer Globigerinoides ruber (white) for all cores, and for the subsurface-dwelling planktonic foraminifer Neogloboquadrina pachyderma (dextral) for core LC21 (habitats after Rohling et al, 2004), and we use conversions to sea level after Rohling et al (2014) Grant et al, 2012;Hennekam, 2015), and recalibrating original 14 C datings with the most recent 14 C calibration curve (Reimer et al, 2013) using a DR value of 35 ± 70 years (Siani et al, 2000).…”