Largest supraglacial lake

The largest lake on top of a glacier forms each year on the surface of the Amery Ice Shelf in East Antarctica, which also forms part of the longest glacier system in the world. The lake forms during the summer months when the surface snow and ice melts and the water collects in a large trough in the ice surface to form what is known as a "supraglacial lake". The largest reported extent of the lake was in January 2017 (during the height of the Antarctic summer) when it was measured at 71.5 square kilometres (27.6 square miles).

The largest lake under a glacier is also in Antarctica. Subglacial Lake Vostok is one of almost 400 lakes trapped beneath the Antarctic Ice Sheet and is 230 kilometres (143 miles) long and up to 50 kilometres (31 miles) wide. It has a surface area of approximately 14,000 square kilometres (5,405 square miles).