Volcanic Explosivity Index
Giuseppe Mercalli also observed eruptions of the volcanoes Stromboli and Vulcano in the Aeolian Islands. His descriptions of these eruptions became the basis for two indices of the Volcanic Explosivity Index: 1 – Strombolian eruption, and 2 – Vulcanian eruption. He also photographed Vesuvius immediately after its eruption in 1906.