Morphometry and characteristics of subglacial meltwater corridors within the Finnish Lake District Ice Lobe of the former Fennoscandian Ice Sheet – Implications for subglacial hydrology and ice lobe dynamics

Abstract

<p>Detailed knowledge of subglacial hydrology is essential for understanding past and future ice sheet behavior, yet direct observations in contemporary settings remain challenging. Subglacial meltwater corridors (SMCs) are composite landforms that record various forms of subglacial drainage and, together with eskers, provide key constraints for past ice sheet reconstructions and future drainage modeling. In the present study, we investigated SMCs in the Finnish Lake District Ice Lobe (FLDIL) of the former Fennoscandian Ice Sheet (FIS). By examining their morphometry, relief types, and association with eskers, our aim was to evaluate how their characteristics relate to regional variations in topography, landform distribution and ice sheet dynamics. Our results demonstrate that bedrock topography, the thickness of glacial overburden, and the presence of potential subglacial lakes exert major control on SMC form and distribution. The spatial pattern of SMC–esker associations also reveals distinct regional variations in dominant drainage modes. These findings support earlier hypotheses of ice flow reorganization events driven by changes in ice sheet configuration and proglacial water depth during deglaciation. In addition, our results highlight significant differences between the dynamics of the western and eastern sectors of the FLDIL lobe and provide new insights into paleo-subglacial lakes as active components of the subglacial drainage system in the Finnish sector of the FIS.<br></p>