Crag-and-tail features: convergent ice flow through Eclipse Sound, Baffin Island, Arctic Canada

Abstract

Elongate glacial landforms are typically orientated in the direction of ice flow (Benn & Evans 2010). They are often preserved in the submarine environment, providing information on past ice-sheet extent and flow pathways. The northeastern margin of the Laurentide Ice Sheet (LIS) covered much of eastern Baffin and Bylot islands during the Last Glacial Maximum (Dyke et al. 2002). Numerous elongate landforms on the seafloor of Eclipse Sound and Pond Inlet indicate the direction of ice flow around Bylot Island in the Canadian Arctic (Fig. 1b; Bennett et al. 2014). Fig. 1. Multibeam swath bathymetry, longitudinal profile, cross-section and sub-bottom acoustic profile of elongate submarine features in Eclipse Sound, Arctic Canada. ( a ) Location of study area (red box; map from IBCAO v. 3.0). ( b ) Sun-illuminated multibeam-bathymetric image of convergent crag-and-tails. Acquisition system Kongsberg Simrad EM300. Frequency 30 kHz. Grid-cell size 10 m. ( c ) Ice-flow lines inferred from crag-and-tails (white lines). Glacier flow is from SW to NE (white arrow). Crag-and-tails are roughly distributed in arcs of decreasing radius from SW to NE (red lines). ( d ) Longitudinal profile through a crag-and-tail (located in (b)). VE×4. ( e ) Cross-profile through crag-and-tails. Black arrows mark five sedimentary tails. VE×8. ( f ) Shallow sub-bottom profile across Eclipse Sound showing …