Bureau scientists Nels Iverson and Nelia Dunbar were co-authors on two papers published in early October. The first paper was published in Climate of the Past on the ice core chronology of the recently drilled South Pole ice core (SPC14). Accurate chronologies of ice cores are crucial for calibrating all other measurements made on the ice core and allow for spatial and temporal relationships of our climate system to be assessed. Iverson and Dunbar provided volcanic event “tie points” which link different ice core records together.
The second paper in Nature-Scientific Reportsclosely examines a large volcanic sulfur peak preserved in the ice core that erupted from an unknown volcano in the mid-15th century. This sulfur peak has been an important chemical marker in many Antarctic ice cores but no source volcano has ever been confirmed, although Kuwae volcano in Vanuatu has been suggested to be the source. The new South Pole ice core contained ash particles in the same time interval as the sulfur peak and their geochemical fingerprint is not similar to Kuwae, suggesting they come from a different volcanic source. Initially, a search for the source volcano in the South Pacific came up with no good candidates until a new paper on Chilean volcanoes allowed for the Reclus volcano to be identified as the source volcano.