**10. Hawaiian eruption**

Some eruptions descriptions have been subdivided into phases for the sake of clarity from the inside to outside volcano.

Phase 1: The ascent rate of the bubble-free basaltic magma is >1 m/s. The low viscosity allows the formation of large bubbles that are brought to the surface (**Figure 29**).

**Figure 26.** *Strombolian eruption schematically explained (author's collection).*

**Figure 27.**

*Paroxysistic phase of the eruption of 1944 AD (author's collection). Photo made from allied force during the second world war.*

Phase 2: The expansion of the large bubbles expels fragments of magma outward from the conduit that forms incandescent lava fountains with a speed of 10–20 m/s reaching heights of 200–500 m (**Figure 29**). The lava fountains erupt

**Figure 28.** *Medieval deposits from a Vesuvius eruption, a sort of Strombolian activity (author's collection).*

**Figure 29.** *Hawaian eruption (taken from the web).*

high-temperature scoriae that falling still hot remobilize lava flow without roots (spatter fed lava flow). Lava fountains can also form in craters occupied by a lava lake.
