Advancing on large-scale trends of apparent organic matter reactivity in marine sediments and patterns of benthic carbon transformation

Abstract

Abstract. Constraining the mechanisms that control organic matter (OM) reactivity and, thus, degradation, preservation and burial in marine sediments across spatial and temporal scales is key to understanding carbon cycling in the past, present, and future. However, we still lack a quantitative understanding of what controls OM reactivity in marine sediments and, as a result, how to constrain it in global models. To fill this gap, we quantify apparent OM reactivity (i.e., model-derived estimates) by extracting reactive continuum model parameters (a and v) from observed benthic organic carbon and sulfate dynamics across 14 contrasting depositional settings distributed over five distinct benthic provinces. Our analysis shows that the large-scale range in apparent OM reactivity is largely driven by the wide variability in parameter a (10−3

Comment on bg-2020-435

“…Data for the Northern European margin sites Aarhus Bay, Arkona Basin, and the Skagerrak transect (Table 1; rows D, E, G, H, and I) are part of the European funded project METROL (Aquilina et al, 2010;Dale et al, 2008aDale et al, , 2008bKnab et al, 2008;Mogollón et al, 2012). Data from the Helgoland Mud Area, North Sea (Table 1; row F) (Henkel and Kulkarni, 2015), the Arabian Sea transect (Table 1; rows J, K, and L) (Bohrmann and cruise participants, 2010a(Bohrmann and cruise participants, , 2010b(Bohrmann and cruise participants, , 2010c, Bering Sea (Table 1; row M) (Gersonde, 2009), and Argentine Basin (Table 1; row N) (Henkel et al, 2011) are presented on PANGAEA database (see above). We use those sitespecific datasets to inform our data-model analysis and to constrain OM reactivity and related benthic processes (Sect.…”

“…(a) Global scale; (b) European margin; (c) Arabian Sea 1010 region. Map produced with Ocean Data View(Schlitzer, 2019).…”