Abstract

Many of the important properties and uses of ice actually depend on impurities that are present: isotopic variants of water molecules, small amounts of soluble and insoluble material derived from the aerosol and gas phase, and the trace constituents of the air bubbles that make up around 10% of the volume of ice at atmospheric pressure. These impurities, and their location within the ice structure, affect local properties of the ice such as the electrical conductivity and mechanical strength, which scale up to give ice sheets their geophysical properties. In addition, the concentrations of different impurities are used to give unique records of palaeoclimate and palaeoenvironmental properties, extending so far 800,000 years back in time. Ice core records from Greenland and Antarctica have for example shown us clearly that the increases in greenhouse gases of the last 200 years are unprecedented in the context of the last 800,000 years; ice cores have shown us that very rapid climate switches, probably related to ocean heat transport, can happen; and they have revealed details of the factors behind the major swings in Earth’s climate from glacial to interglacial conditions that occur roughly every 100,000 years. The talk will mix discussion of the analytical chemistry behind the measurements and the environmental chemistry that influences the climate.