Evidence of old carbon in the deep water column of the Panama Basin from natural radiocarbon measurements
Published Web Locationhttps://doi.org/10.1029/98GL01157
Radiocarbon (Δ14C) analyses were performed on sinking and suspended particulate matter, dissolved inorganic carbon (DIC), sediment and sediment fluff from a deep-water station in the Panama Basin. Δ14C signatures for sinking particulate inorganic and organic carbon (PIC, FOC) collected at 3354 meters depth were lower than surface DIC Δ14C values, and higher than the inorganic and organic carbon from the sediment (SIC, SOC). We compare these data with those obtained for other Pacific and Atlantic sites and show that the gradient between surface DIC Δ14C and deep suspended POC Δ14C is the same irrespective of distance from the coast. This indicates that: 1) resuspended SOC is an equally important contributor to deep POC at locations close to and far from continental slopes, and/or 2) DOC sorption is a significant contributor for causing low Δ14C values of deep POC.