Lateral transport facilitates terrestrial organic carbon burial in the Santa Barbara Basin over the past 80 years (1937–2018 CE)
Journal
Palaeogeography, Palaeoclimatology, Palaeoecology
Journal Volume
653
Start Page
112407
ISSN
0031-0182
Date Issued
2024-11
Author(s)
Abstract
Small mountainous rivers (SMRs) play a crucial role in cycling of organic carbon (OC) within the land-to-ocean aquatic system. Heavy rainfall-induced river floods and hyperpycnal plumes are essential for the efficient transfer of terrestrial OC from the land biosphere to long-lived marine sediments, yet the quantitative assessment of its contribution remains poorly constrained. Here we used the OC content, C/N ratio, carbon isotopes (δ13C, Δ14C), and dry bulk density of a sediment core (SBB-190629) to track the temporal changes of terrestrial OC deposition in the Santa Barbara Basin (SBB) over the past 80 years (1937–2018 CE). By combining data from a sediment trap (CCS-Forams), we estimated the mass accumulation rate of lateral-transported terrestrial OC, which accounts for 62–79% of terrestrial OC buried in the SBB. We suggest that heavy rainfall-induced hyperpycnal plumes facilitate rapid transport of terrestrial OC from the Santa Clara River estuary into the SBB depo-center, resulting in increased burial flux of terrestrial OC during years with heavy rainfall. This study underscores the significant role of lateral transport processes in transferring terrestrial OC within the land-to-ocean aquatic system.
Subjects
Hyperpycnal plumes
Lateral transport
Santa Barbara Basin
Terrestrial organic carbon
Publisher
Elsevier BV
Type
journal article