Scientists explain how meltwater reaches ocean depths

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An international team of researchers has discovered why fresh water, melted from Antarctic ice sheets, is often detected below the surface of the ocean, rather than rising to the top above denser seawater. The team found that the Earth’s rotation influences the way meltwater behaves – keeping it at depths of several hundred metres. The research is published this week in the journal Nature in association with colleagues at University of Southampton, National Oceanography Centre, Southampton, University of East Anglia (UEA), British Antarctic Survey (BAS) and Stockholm University.

An international team of researchers has discovered why fresh water, melted from Antarctic ice sheets, is often detected below the surface of the ocean, rather than rising to the top above denser seawater. The team found that the Earth’s rotation influences the way meltwater behaves – keeping it at depths of several hundred metres. The research is published this week in the journal Nature in association with colleagues at University of Southampton, National Oceanography Centre, Southampton, University of East Anglia (UEA), British Antarctic Survey (BAS) and Stockholm University.

Professor Alberto Naveira Garabato, of Ocean and Earth Science at the University of Southampton and lead author of the study, says:  “We believe our study is an important step in understanding how the meltwater mixes in the ocean and will help with the design of climate models, which largely assume meltwater is only present on the surface of oceans. Our research emphasises its detection at greater depths and explains why it is found there.”

The researchers made their discovery during an expedition in the Southern Ocean, led by Professor Karen Heywood of UEA, on British Antarctic Survey’s Royal Research Ship James Clark Ross.  The trip was undertaken in 2014 as part of the NERC-funded iSTAR programme4.  The team measured turbulence experienced by meltwater as it flowed out of a cave beneath the Pine Island Glacier – one of the fastest melting glaciers in Antarctica.  They used a VMP23 (Vertical Microstructure Profiler) to detect subtle fluctuations in the water.

Read more at British Antartic Survey

Image Credits: University of Southampton