Factors affecting the dynamics of the North Karelian/Oulu Ice Lobe, Central Finland, during the last deglaciation – a LiDAR and DEM interpretation of subglacial lineation patterns

• Published in: Bulletin of the Geological Society of Finland
• Main Authors: T. Nikarmaa, J.P. Lunkka, N. Putkinen
• Format: Article in Journal/Newspaper
• Language: English
• Published: Geological Society of Finland 2017
• Subjects: LiDAR; Scandinavian ice sheet; Oulu; Northern Ostrobothnia; glacial lineations; streamlined formations; Mega-scale glacial lineations; Kalevala end moraine; Geology; QE1-996.5; Ice Sheet; karelia*; karelian
• Online Access: https://doi.org/10.17741/bgsf/89.2.003; https://doaj.org/article/168f7874f1164ec094c76eb597d1c4c4

The SIS (Scandinavian Ice Sheet) became divided into several active, semi-independent ice lobes during the last deglaciation ca 13 000–10 000 years ago. The largest of them, the North Karelian/Oulu Ice Lobe (NKIL/OIL), covered vast areas in central Finland and in northwest Russian Karelia. This paper studies the behaviour and subglacial conditions of the NKIL/OIL with the inversion modelling method. The method is based on the identification and interpretation of mapped glacigenic streamlined lineations, formed during active flow stages of the NKIL/OIL. DEM and LiDAR data on lineations was obtained from seven subsets in different zones of the NKIL/OIL. Results indicate that the NKIL/OIL dynamics were strongly affected by pre-existing Quaternary sediment thickness, bedrock lithology, structures and topography. Due to these factors, the NKIL/ OIL operated through several flow corridors and had several retreat and re-advance cycles throughout its life span.