How are volcanic eruptions recorded in ice?
The second reason is the change in the earths temperature created by volcanic eruptions. At cold periods more water is formed in the upper atmosphere with heavy oxygen. Heavy oxygen is an isotope of oxygen (greater number of neutrons) this is measurable and allows scientist to predict what the climate used to be like (paleoclimatology). A very quick change in climate may be in be caused by a vast eruption and hence can be seen in the isotopic ratios of oxygen within ice cores.
