Ice core and palaeoclimatic evidence for the timing and nature of the great mid-13th century volcanic eruption
Ice cores from both the Arctic and Antarctic record a massive volcanic eruption in around AD 1258. The inter-hemispheric transport of ash and sulphate aerosol suggests a low-latitude explosive eruption, but the volcano responsible is not known. This is remarkable given estimates of the magnitude of the event, which range up to 5 × 1014-2 × 1015 kg (200-800 km3 of dense magma), which would make this the largest eruption of the historic period, and one of the very largest of the Holocene. The associated collapse caldera could have had a diameter up to 10-30 km. Palaeoclimate reconstructions indicate very cold austral and boreal summers in AD 1257-59, consistent with known patterns of continental summer cooling following tropical, sulphur-rich explosive eruptions. This suggests an eruption in AD 1257, producing a stronger climate forcing than hitherto recognized.