Undersea anchors of ice that help prevent Antarctica's land ice from slipping into the ocean are shrinking at more than twice the rate compared with 50 years ago, research shows. More than a third of these frozen moorings, known as pinning points, have decreased in size since the turn of the century, experts say. Further deterioration of pinning points, which hold in place the floating ice sheets that fortify Antarctica's land ice, would accelerate the continent's contribution to rising sea levels, scientists warn.
