Text and photos: Henry Patton, chief scientist
Even by generous estimates, around 80% of the world’s oceans have not been surveyed – the surface of Mars is better mapped than our own planet. This fact rings true in the Barents Sea as well, where there are still vast areas where we don’t really know what the seafloor looks like. Imaging and reconstructing the landform imprint left behind by the last ice sheet is therefore much like trying to complete a vast unfinished jigsaw puzzle, where there are still more pieces left in the box than on the table.
Here is one such jigsaw piece we found and surveyed this week. This impressive channel feature carried vast quantities of water beneath the ice sheet, which perhaps came via vertical pipes that captured meltwater from the ice-sheet surface above. Like in river systems that you see onshore, there are similar morphologies in these subglacial features too, including channel braiding and the occasionally connected lake basin.
Knowing these features exist and that water was abundant gives us clues into what conditions were like at the base of the ice sheet, and into the processes of how the ice sheet eventually collapsed.
Surveying the seafloor is a frustratingly slow process – to get images of sufficient quality we are sailing at less than 20 km per hour. However, the live data feed that comes in makes great ‘slow TV’ for geoscientists! From the warmth of the instrument room, it’s possible to be captivated for hours, watching as the glacial landforms slowly reveal themselves and never knowing what to expect next. Of course, there are many teasing features that we see along the way that would be great to visit, but time is limited and we must be patient and come back another year to add more pieces to the puzzle.
