*The Somma-Vesuvius Activity with a Focus to the AD 79 Eruption: Hazard and Risk DOI: http://dx.doi.org/10.5772/intechopen.89989*

for the construction of a new stratovolcano, the Vesuvio, which grew within the Somma caldera [14–19]. Since 1550, many coeval chronicles and the pictures of the Atlas by the cartographer Gerardus Mercator (1512–1594) make it possible to deduce that in this time span the Vesuvius was quiescent and that Gran Cono was covered by a closely cropping vegetation. On December 16, 1631, Vesuvius resumed its activity after 500 years of quiescence period. The eruption, with both effusive and explosive products, was not expected by the inhabitants, who were not aware that Vesuvius was an active volcano (**Figure 20**). Famous label was placed at Portici by Spanish viceroy after the AD 1631 eruption to warn the future generation about the volcanic risk of the Vesuvius (**Figure 21**). From 1631 to 1944, the last interplinian phase occurred. The typical volcanic activity, effusive and weak explosive, was developed according to a succession of volcanic cycle, called vesuvian cycle. Between the end of eighteenth century and the first half of the nineteenth century, in the absence of photographs,

**Figure 22.** *(a) December 1760 eruption, Fabris. (b) October 20, 1767, Fabris (c) June 1794 eruption.*

*Forecasting Volcanic Eruptions*

the mediaeval interplinian period occurred. During this period, the volcano alternates quiescence periods to effusive phases with low energy Strombolian style eruptions. The last reliable historical reports about this long time span concern the effusive activity that took place in 1139. The mediaeval interplinian activity was responsible

*Engraving showing Somma-Vesuvius during a repose period before the 1631 eruption.*

*Portici marble label as the first action of Civil Protection at Somma-Vesuvius after the 1631 eruption.*

**94**

**Figure 21.**

**Figure 20.**

#### *Forecasting Volcanic Eruptions*

grew, in Napoli, painters "a la gouaches." These artists represented the wonderful landscapes of the vesuvian area. Their pictures are the precious examples of the Neapolitan "vedutismo" (**Figure 22**).

A progressively increasing of both strombolian and effusive intracrateric activity preceded the 1822 paroxysm. In September, an appreciable seismic activity was recorded and also many springs of the vesuvian area dried up. After some volcanic eruptions, on October 20 and 21 during the night, finally the lava overflowed the crater rim and directed toward Resina (Ercolano) (**Figure 23**). In these years, on the southern flank of Vesuvius, above the Salvatore hill, the building of the first volcanological observatory of the world, the **Osservatorio Meteorologico Vesuviano**, was built. It was officially inaugurated on September 28, 1845, during the Conference of Italian Scientists held in Napoli.

This particular moment in history signaled for the people living there at a transition from a phase of fear of the volcano to one of lasting and increasing knowledge (**Figure 24**). The 1906 eruption was the paroxysmal phase of the Vesuvian cycle

**Figure 23.** *Interplinian eruption of 1822.*

**97**

**Figure 26.**

**Figure 25.**

*1906 eruption: eruptive column and lava flow.*

*suggest the height of the 1944 eruption column.*

*The Somma-Vesuvius Activity with a Focus to the AD 79 Eruption: Hazard and Risk*

1874–1906. The eruption was observed and described by many Italian and foreign volcanologists. For the first time with 1906 eruption, Vesuvius photos were diffused in the scientific world also due to the contribution of newspapers and magazines (**Figure 25**). In 1913, the last Vesuvian cycle of the modern historic interplinian phase started, and on March 18, 1944, the paroxysmal eruption began (**Figure 26**). It was not long after the war that Italian people, especially those around Vesuvius, were busy sorting out other problems. The volcano eruption almost seemed like the lesser of two evils when compared to the destruction wrought by the Second World War in Campania. During the eruption, the Allied Force Command was involved in bringing an enormous help, through evacuation, to the population of Vesuvian municipalities and, in particular, of San Sebastino, which was firstly threatened and then invaded by lava flows (**Figure 27**). In 1944, Vesuvius entered a quiescence phase still now lasting, even if every now and then low magnitude seismic events,

*1944 eruption: beginning of the eruption followed by a Vulcanian style eruption with an allied plane that* 

*DOI: http://dx.doi.org/10.5772/intechopen.89989*

**Figure 24.** *Historical Vesuvian Observatory (first volcanological observatory on earth).*

## *The Somma-Vesuvius Activity with a Focus to the AD 79 Eruption: Hazard and Risk DOI: http://dx.doi.org/10.5772/intechopen.89989*

1874–1906. The eruption was observed and described by many Italian and foreign volcanologists. For the first time with 1906 eruption, Vesuvius photos were diffused in the scientific world also due to the contribution of newspapers and magazines (**Figure 25**). In 1913, the last Vesuvian cycle of the modern historic interplinian phase started, and on March 18, 1944, the paroxysmal eruption began (**Figure 26**). It was not long after the war that Italian people, especially those around Vesuvius, were busy sorting out other problems. The volcano eruption almost seemed like the lesser of two evils when compared to the destruction wrought by the Second World War in Campania. During the eruption, the Allied Force Command was involved in bringing an enormous help, through evacuation, to the population of Vesuvian municipalities and, in particular, of San Sebastino, which was firstly threatened and then invaded by lava flows (**Figure 27**). In 1944, Vesuvius entered a quiescence phase still now lasting, even if every now and then low magnitude seismic events,

**Figure 25.** *1906 eruption: eruptive column and lava flow.*

#### **Figure 26.**

*1944 eruption: beginning of the eruption followed by a Vulcanian style eruption with an allied plane that suggest the height of the 1944 eruption column.*

*Forecasting Volcanic Eruptions*

Neapolitan "vedutismo" (**Figure 22**).

the Conference of Italian Scientists held in Napoli.

grew, in Napoli, painters "a la gouaches." These artists represented the wonderful landscapes of the vesuvian area. Their pictures are the precious examples of the

A progressively increasing of both strombolian and effusive intracrateric activity preceded the 1822 paroxysm. In September, an appreciable seismic activity was recorded and also many springs of the vesuvian area dried up. After some volcanic eruptions, on October 20 and 21 during the night, finally the lava overflowed the crater rim and directed toward Resina (Ercolano) (**Figure 23**). In these years, on the southern flank of Vesuvius, above the Salvatore hill, the building of the first volcanological observatory of the world, the **Osservatorio Meteorologico Vesuviano**, was built. It was officially inaugurated on September 28, 1845, during

This particular moment in history signaled for the people living there at a transition from a phase of fear of the volcano to one of lasting and increasing knowledge (**Figure 24**). The 1906 eruption was the paroxysmal phase of the Vesuvian cycle

**96**

**Figure 24.**

*Historical Vesuvian Observatory (first volcanological observatory on earth).*

**Figure 23.**

*Interplinian eruption of 1822.*

**Figure 27.** *1944 lava flow invaded the San Sebastiano al Vesuvio.*

**Figure 28.** *Vesuvius crater after the 1944 explosive eruption.*

together with a continuous fumarolic activity at the crater, remind people that, although dormant, the volcano is still active (**Figure 28**).
