Chronologically constrained marine Spheroidal Carbonaceous Particle (SCP) record for Svalbard (Greenland Sea, Arctic Ocean)

Spheroidal Carbonaceous Particles (SCPs) are a component of fly-ash formed during the high temperature combustion of coal and fuel-oil. They have no natural sources and the marked increase in their concentration, concurrent with the ‘Great Acceleration’ in the 1950s CE, has previously been proposed as a marker for the ‘Anthropocene Epoch’. To define if sediments are less than ~200 years old, SCPs are proposed to offer a reliable and cost-effective method to determine sediments of industrial era age. They can improve and extend (by decades) age models where chronologies such as 210 Pb are hampered by high sedimentation rates and therefore dilution. Here, we present the first published SCP record for the marine realm in Svalbard, and for the entire Arctic Ocean. The first appearance of SCPs is dated to ~1856 CE, a first peak in SCP concentration is observed in the 1950s-70s CE and a secondary smaller peak corresponds with maximum total consumption of coal at local power plants occurring in the early 1990s CE. The observed SCP profile is supported by independent 210 Pb dating and is shown to be reproduceable as it is detected in two different marine sediment cores. Evidence presented here therefore demonstrates that the proposed global SCP pattern, as also previously observed in the NW Atlantic, subpolar N Atlantic and Baltic Sea, is recorded in remote areas of the Greenland Sea and provide further evidence for early anthropogenic influence in the high Arctic. This study shows the potential for using SCPs in the wider Arctic to improve the chronology of marine sedimentary sequences that cover the overlap between instrumental observations and proxy reconstructions.