How Do We Measure the Climatic Effects of Volcanic Eruptions?
There are two main indeces used to assess the effects of volcanic eruptions on climate. They are the Dust Veil Index (DVI) and the Volcanic Explosivity Index (VEI). The Dust Veil Index (DVI) is based on estimations of the amount of material dispersed into the atmosphere as well as the temperatures at and amount of sunlight reaching the Earth’s surface. This index is unfortunately dependant on observations made at mid-latitudes and therefore only really representative of the effects of eruptions on mid-latitude climate. The Volcanic Explosivity Index (VEI) is a system that ranks eruptions using only volcanological criteria to assess the magnitude, intensity, dispersion and destructiveness of a volcanic event. It does not rely on temperature and solar radiation measurements at the surface so it can be useful for worldwide eruptions. These eruptions are ranked from 1 to 8 with 8 being the most explosive. Those eruptions presumed to have injected material into the stratosphere have a VEI o