Source‐to‐Sink Signal Propagation in a Small, Coupled Catchment‐Deep‐Sea Fan System: The Sithas Example From the Corinth Rift (Pleistocene, Greece)

ABSTRACT Quantifying sediment fluxes is an essential part of the Source‐to‐Sink approach in the understanding of sedimentary systems. However, the transfer of sediment from the source to the sink and the factors controlling it are still poorly understood. We focus on a small catchment coupled with its offshore deep‐sea fan: the Sithas system (Gulf of Corinth, Greece). We restore the volume of sediment eroded in the catchment using geomorphic constraints; quantify the volume of sediment deposited in the offshore basin, after revising the age model; and calculate erosional fluxes using the BQART model. This allows for the comparison of the reconstructed fluxes of sediment eroded and deposited since 800 ka across the entire source‐to‐sink system. For the Sithas coupled catchment‐deep‐sea fan system, we show an increase in sedimentary fluxes both in erosion and deposition since 800 ka and particularly since 400 ka, where cyclic variations of ~120 kyr are recorded in erosion and deposition compartments. We suggest that the overall increase in flux results from a change in the catchment size due to the tectonic evolution of the region. The record of cyclic variations from 400 kyr in fluxes matches with the maturity of the system and with the intensification of glacial cycles and tectonic constraints migration. We also suggest that the discrepancy between erosion and deposition reflects a temporary storage between source and sink areas, probably along the coast. This has changed since 30 ka, introducing the last phase of evolution characterised by phased source and sink dynamics, suggesting a lack of temporary storage and a connection between river outlet and submarine canyon head. This study shows that sediment fluxes are controlled by the catchment's size as well as by climatic and tectonic factors and that even a small sedimentary system can be affected by temporary sediment storage.