Seasonal stable oxygen isotope cycles in an Antarctic bivalve shell (<i>Laternula elliptica</i>): a quantitative archive of ice-melt runoff

Abstract

Oxygen isotope ratios in the shell of a Recent Antarctic marine bivalve Laternula elliptica are shown and their potential for environmental reconstruction is discussed. The shell δ 18 O profiles of this species represent the seasonal change in melted ice water inflow. Oscillations in the shell δ 18 O values reflect seasonal change in seawater δ 18 O values, caused by an addition of meltwater in summer. Since annual temperature variation is minimal and the inflow of the regional ice-melt is the dominant control on the shell δ 18 O values, the oxygen isotope record of L. elliptica is a quantitative indicator of the palaeo-ice-melting events in the Antarctic continental margin.