It was Johan who first noticed, during a patrol of our Ice Surface Observatory, a tall jet of water bursting from the ice surface several kilometers to the West, punctuating the otherwise flat horizon. Out first thought was that this could be spray from water gushing into a huge moulin.
We then noticed this spray kicked off in the afternoon every day, shortly after the day’s peak melt, supporting our moulin spray hypothesis. As it turned out, the helicopter pilot flying our first ‘dash’ was as interested as we were and agreed to an impromptu flyover of the site. This solved the mystery – there was indeed a huge moulin at the site, but this was not the source of the jet – it was spray from a huge volume of fast-flowing meltwater cascading down a step and into a sharp bend in a supraglacial stream.
I was lucky enough to capture this film of the flyover…
PDRA at the University of Sheffield. 2016 Rolex Young Laureate. Rock climber.