Glaciers in the Antarctic are being melted from below by a newly discovered process that adds to fears over rising sea levels and climate change.

A study revealed a previously undocumented process where melting glacial ice sheets change the ocean in a way that further accelerates the rate of ice melt and sea level rise.

The findings show that glacial meltwater makes the ocean's surface layer less salty and more buoyant, preventing deep mixing in winter and allowing warm water at depth to retain its heat and further melt glaciers from below.