**7. Explosive volcanism**

Explosive volcanism can be classified into two types, as shown in **Table 3**. The internal and external eruptive dynamics of the volcano consist of two phases: Phase 1: Exsolution of volatiles from the over-saturated magma, and explosive fragmentation of magma with the conversion of thermal energy in kinetic energy. Phase 2:

#### **Figure 21.**

*Draw that show how magma evolves through a pyroclastic material (exsolution and fragmentation). Modified from Cortini and Scandone [25].*

#### **Figure 22.**

*Diagram of the explosiveness versus the height of the eruptive column. Modified from Cas and Wright [8].*

Expulsion of the mixing composed of fragments of solidified magma and gas, and a formation of an eruptive column (**Figure 21**). The two phases are initially connected and determine the explosive style of the eruption. As follow a diagram of the Classification of explosive eruptions with two volcanological parameters (Explosiveness-Height of the pyroclastic column) (**Figure 22**). This diagram explains the differences between various types of volcanic eruptions. Diagram is redrawn after Cas and Wright [8].
