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<\/div>Aerial view of an ice sheet in Antarctica<\/p>\n
David Vaughan\/BAS<\/p>\n<\/div>\n<\/figcaption><\/figure>\n<\/p>\n
Antarctica\u2019s melting ice sheets may retreat faster as warm seawater intrudes underneath them. Warming ocean temperatures could also lead to a \u201crunaway\u201d feedback effect that allows warm seawater to push further inland, leading to more melting and faster sea level rise.<\/p>\n
As the climate warms, the future of Antarctica\u2019s vast ice sheets remains uncertain, with projections ranging widely for how rapidly they will melt and therefore how much they will contribute to sea level rise. One dynamic that researchers have only recently come to view as an important factor are intrusions of warm seawater beneath the ice.<\/p>\n
\u201cThe intrusion mechanism is a lot more powerful than we previously understood,\u201d says Alexander Bradley<\/a> at the British Antarctic Survey.<\/p>\n Such intrusions occur due to the difference in density between the fresh water flowing out from beneath the ice sheet and the relatively warm ocean water where the ice meets the seafloor \u2013 an area known as the grounding line. This is difficult to directly observe as it occurs beneath hundreds of metres of ice, but simulations suggest the warm water could extend inland for kilometres in some places.<\/p>\n <\/p>\n One model <\/a>by Alexander Robel<\/a> at the Georgia Institute of Technology in Atlanta and his colleagues found extensive intrusions could more than double the amount of ice loss from an ice sheet by adding heat from below and lubricating the flow of ice along the bedrock.<\/p>\n