Reservoir ages in the western tropical north Atlantic from one coral off Martinique Is (Lesser Antilles)

Sea surface reservoir ages (R) are reported from radiocarbon (C-14) measurements of the annual growth bands of coral Siderastrea siderea collected on the Atlantic coast off Martinique Island, in the Lesser Antilles volcanic arc.

Mean values of R are similar between 1835 and 1845 during pre-anthropogenic times at 385 +/- 30 yr and between 1895 and 1905 at 382 +/- 20 yr when there was a huge eruption from the Montagne Pelee volcano in 1902-1903. Limited C-14 aging of sea surface (similar to 40 yr) may be due to enhanced volcanic activity. Variability of R is slightly greater during 1835-1845 than during 1895-1905. It is linked to a moderate increase of Delta C-14 of 5 parts per thousand, strengthened by a clear increase of O-18 of delta 0.4 parts per thousand. This is attributed to a decrease of the northward advection of the South Atlantic Waters into the western tropical North Atlantic and Caribbean Sea and relative enhanced westward flux of the tropical North Atlantic surface waters, the southern waters having lower values of C-14 and delta O-18 than the North Atlantic ones. From 1835 to 1845, the fraction of the South Atlantic Waters transported up to Martinique Island was reduced from 25% to 15%.oteurs de recherche.

Figures: A) Location of the samples cited in the text and schematic patterns of the oceanic currents. 1: Martinique 2: Cariaco basin (Guilderson et al., 2005); 3: Puerto- Rico (Kilbourne et al., 2007); 4: Belize (Druffel, 1980); 5: Gulf of Mexico (Wagner et al., 2005); 6: Florida (Druffelet Linick, 1978; Druffel, 1980, 1982); 7: Bahamas (Fernandez et al., 2012); 8: Bermuda North shore (Druffel, 1989; 1997); 9: Bermuda South shore (Goodkin et al., 2012); 10: Santa Helena (Lewis et al., 2008). NEC: North Equatorial current; NECC: North equatorial undercurrent; NBC: North Brazil current; GC: Guiana Current; SEC: South Equatorial current; EAW: East Atlantic current; CC: Caribbean current; GS: Gulf Stream. The 1000m isobath is represented. B)Values of the sea surface reservoir ages R (years) off Martinique and at the sites located on Figure 1A as a function of calendar years (AD). Grey box figures out the 2yr long eruption of Montagne Pelée.

Reference: Paterne M, Feuillet N, Cabioch G, et al. Reservoir Ages in the Western Tropical North Atlantic from One Coral off Martinique Island (Lesser Antilles). Radiocarbon. 2018;60(2):639-652. doi:10.1017/RDC.2017.118