Based on a systemic approach, this study intends to characterize the patterns and the temporal rhythms of the glacio-fluvial continuum adjustment to the post-Little Ice Age climate change. According to lichenometric dating and quantification of the glacial and fluvioglacial responses of fifteen glaciers tongues and sandurs in south-Iceland, the range of observed adjustments scenarios is explored. The heterogeneous and asynchronous nature of responses are tested and the variables controlling the observed adjustment variability are identified. Based on the collected and analyzed data sets: (i) we highlight the asynchronous LIA maximum extent of south-Icelandic glaciers and the significant heterogeneity in glacier fronts retreat intensity which both reflect the complex nature of glacier response to climate change; (ii) we suggest the existence of marginal processes akin to self-organized criticality which control sediment transport efficiency and water discharges; (iii) we identify a prevailing pattern for the post-LIA fluvial adjustment of sandur type I and the independent response of jökulhlaup sandur (type III) to glacier front fluctuations.