The Influence On Atmospheric Composition of Volcanic Eruptions as Derived From Ice-Core Analysis

Abstract

Polar ice cores offer datable past snow deposits in the form of annual ice layers, which reflect the past atmospheric composition. Trace substances in the cores are related to the past mid-tropospheric impurity load, this being due to the vast extent of the polar ice sheets (or ice caps), their surface elevations and remoteness from most aerosol sources. Volcanic eruptions add to the rather low background impurity load via their eruptive products. This paper concentrates on the widespread influence on atmospheric impurity loads caused by the acid gas products from volcanic eruptions. In particular the following subjects are discussed: acid volcanic signals in ice cores, latitude of eruptions as derived by ice-core analysis, inter-hemispheric dating of the two polar ice sheets by equatorial eruptions, volcanic deposits in ice cores during the last glacial period and climatic implications.