Nobody in Rome or Carthage Seems to have noticed the catastrophic meltdown of a large patch of Antarctic ice cap in the third century BC, but the evidence is staggering - a 23,000 square kilometer field of volcanic fallout from a crater that punched a hole in a half mile of overlying ice.
A recent volcanic eruption beneath the West Antarctic ice sheet
... radar data from the Hudson Mountains, West Antarctica5... had previously been interpreted erroneously as the ice-sheet bed. We show that the reflections are present within an elliptical area of about 23,000 km2 that contains tephra from an explosive volcanic eruption... which we term the Hudson Mountains Subglacial Volcano. The layer depth dates the eruption at 207 BC240 years, which matches exceptionally strong but previously unattributed conductivity signals in nearby ice cores. The layer contains 0.019–0.31 km3 of tephra, which implies a volcanic explosive index of 3–4.
Production and episodic release of water from the volcano probably affected ice flow at the time of the eruption. Ongoing volcanic heat production may have implications for contemporary ice dynamics...