New insights into the formation of submarine glacial landforms from high-resolution Autonomous Underwater Vehicle data

摘要: Abstract Autonomous Underwater Vehicles (AUVs) deployed close to the seafloor can acquire high-resolution geophysical data about topography and shallow stratigraphy of seabed, yet have had limited application within fields glacial geomorphology ice sheet reconstruction. Here, we present multibeam echo-sounding, side-scan sonar, sub-bottom profiler High-Resolution Synthetic Aperture Sonar (HISAS) acquired during three AUV dives on northeast Antarctic Peninsula continental shelf. These enable landforms, including mega-scale lineations (MSGLs), grounding-zone wedges (GZWs) iceberg ploughmarks, be imaged at a horizontal resolution few tens centimetres, allowing for identification subtle morphological features. We map tidal ridges that are interpreted as having been formed 1) along ice-sheet grounding line by squeezing up soft sediments vertical motion cycles, 2) tidally driven grounded or near-grounded icebergs. also mapping small GZWs show location short-term still-stands re-advances zone. No meltwater channels identified from our data, suggesting free-flowing may not essential formation MSGLs. The examples presented here how AUV-derived provide step-change in ability image enabling new interpretations past dynamics sedimentation fine temporal spatial scales.