Sediment Accumulation and Carbon Burial in Four Hadal Trench Systems

Hadal trenches are considered to act as depocenters for organic material, although pathways the material transport and deposition rates poorly constrained. Here we assess focusing, accumulation of carbon in four hadal trench systems underlying different surface ocean productivities; eutrophic Atacama Kuril-Kamchatka trenches, mesotrophic Kermadec oligotrophic Mariana Trench. The study is based on distributions naturally occurring 210Pbex, 137Cs total from recovered sediment cores by applying previously quantified benthic mineralization rates. Periods steady discreet mass-wasting deposits were identified profiles latter associated with historic recorded seismic events respective regions. During periods without mass wasting, estimated focusing factors along axes elevated, suggesting more or less continuous downslope toward interior trenches. during these exhibited extensive site-specific variability, but generally similar values encountered at much shallower settings such continental slopes margins. Organic not mirrored productivity, appeared confounded local bathymetry. inclusion mediated enhanced accumulations past ?150 years up a factor ?4. Thus, due intensified infrequent events, important sites sequestration deep sea.