(CNN) What may have been the world's tallest waterfall briefly formed on Greenland's ice sheet last year, draining a meltwater lake of 5 million cubic meters of water -- equivalent to 2,000 Olympic-sized swimming pools -- in just five hours.

Drone imagery captured the lake drainage in unprecedented detail.

Scientists from the University of Cambridge in the UK recorded the extraordinary phenomenon through the use of aerial drones.

Their study, published this week i n the journal Proceedings of the National Academy of Sciences, investigates the link between this transfer of meltwater to the bottom of the ice and rising global sea levels. Greenland has the world's second-largest ice sheet, and is the single largest contributor to global sea-level rise, the study said.

"Before this study, we already knew that many lakes drain and that fractures may be important in the lake drainage process, but the formation of fractures in terms of 'where', 'when' and 'how' has not been studied before, at least not with the resolution and details featured in our work," one of the researchers, Poul Christoffersen, from Cambridge's Scott Polar Research Institute, who led the research told CNN via e-mail.

A meltwater lake on the Greenland ice sheet as viewed from a drone

Caused by cracks forming on the ice sheet, these cascades are responsible for dumping huge quantities of surface water to the ice bed, where it can accelerate the movement of ice towards the sea. After draining, lakes leave behind holes called moulins, which allow meltwater to continue to travel to the bottom of the ice sheet.

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