A rare dataset collected by instruments at the point where Antarctica’s largest ice shelf begins to float reveals ocean processes that drive melting at this critical part of the continent.

During a 2019 expedition to the Kamb Ice Stream, a river of ice which feeds the Ross Ice Shelf, we were able to deploy a string of hydrographic instruments into a thin wedge of ocean beneath the shelf where it begins to lift off at a latitude of nearly 83 degrees South.

The instruments collected data on changing currents, temperature and salinity for nine months before they started to succumb to the extreme conditions.

Our initial analysis suggests the ocean cavity under the ice remains stratified into two layers. The lower layer consists of ocean water, but the upper layer is a mix of ocean and melt water.

Our new research shows the ocean deep beneath the Ross Ice Shelf is cool but much more variable than originally thought – responding to tidal flows as well as the shape of the seabed and the underside of the ice.

New data show warmer water appearing at the periphery of the ice shelf and in some isolated parts of the cavity. How this warm water could make its way into these southernmost limits of the ice shelf cavity is an important question for how Antarctica might respond to a changing........

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