The exact number of volcanologists in the world is difficult to determine because volcanology combines many different elements of the geological sciences. Nonetheless, the International Association of Volcanology and Chemisty of the Earth's Interior, which is the main professional organization for volcanologists, currently has around 1500 members from around the world. This includes people from many sub-disciplines that study every aspect of volcanoes. However, the number of people that monitor and work on actively erupting volcanoes is much more limited and is probably only at most several hundred people throughout the world.