Kuwae Caldera and Climate Confusion

A circular argument has been developed and further propagated through a series of studies that link a major climate-modifying eruption in the 15th century with Kuwae caldera in Vanuatu. Clear evidence in both N and S hemispheres suggests a major eruption with global atmospheric sulphur loading occurred in 1455-56. Concurrent 14C determinations from pyroclastic units and estimations of caldera size have been used to link this event to Kuwae. The 1964 defined and 1994 relocated “Kuwae” caldera structures are both large, but our recent proximal mapping and earlier archaeological studies reveal no evidence for a high intensity (VEI 6) eruption of this age from either centre. Instead, the mid 1400’s strata record localised pyroclastic flow deposition from multiple events, with little evidence for fall deposits. Depositional and clast character imply a largely or wholly submarine nature of the eruptions, indicating they were unlikely to have generated global climate impacts.