What happens if Mount Vesuvius erupts again?


“The Vesuvius is in front of me. Now it is blazing and smoking. What an extraordinary sight! imagine an enormous firework that does not stop for even a minute” Nicolaj V. Gogol’, 1838

Underneath Vesuvius lies a big magma chamber, about 10 km deep. Researchers discovered that there are about 400 kmq of liquid magma, which means it’s possible to give power to eruptions for thousand of years. The city beneath the volcano is still expanding, unware of the danger. At present, more than 500,000 people live in the area (18 villages).

Italian authorities have renewed the cash offer of up to 30,000 euros (about $40,000) for any family wishing to move outside the shadow of Mount Vesuvius in the attempt to reduce the potential hazard of what has been described as the world’s most dangerous volcano. Campania, the region that includes Naples, last month set up a 30 million euro ($40 million) Vesuvius hazard risk program, confirming and improving last year’s cash offer for those wishing to relocate to safer areas.



The volcano hasn’t blown its top since 1944. At that time, lava destroyed some orchards and homes and 26 people were killed.

“The government emergency plan for an eruption therefore assumes that the worst case will be an eruption of similar size and type to the 1631 VEI 4 one. In this scenario the slopes of the mountain, extending out to about 7 kilometres (4.3 mi) from the vent, may be exposed to pyroclastic flows sweeping down them, whilst much of the surrounding area could suffer from tephra falls. Because of prevailing winds, towns to the south and east of the volcano are most at risk from this, and it is assumed that tephra accumulation exceeding 100 kg/m² – at which point people are at risk from collapsing roofs – may extend out as far as Avellino to the east or Salerno to the south east. Towards Naples, to the north west, this tephra fall hazard is assumed to extend barely past the slopes of the volcano. The specific areas actually affected by the ash cloud will depend upon the particular circumstances surrounding the eruption.
The plan assumes between two weeks and 20 days’ notice of an eruption and foresees the emergency evacuation of 600,000 people, almost entirely comprising all those living in the zona rossa (“red zone”), i.e. at greatest risk from pyroclastic flows.\The evacuation, by trains, ferries, cars, and buses is planned to take about seven days, and the evacuees will mostly be sent to other parts of the country rather than to safe areas in the local Campania region, and may have to stay away for several months. However, the dilemma that would face those implementing the plan is when to start this massive evacuation, since if it is left too late then thousands could be killed, while if it is started too early then the precursors of the eruption may turn out to have been a false alarm. In 1984, 40,000 people were evacuated from the Campi Flegrei area, another volcanic complex near Naples, but no eruption occurred.
Ongoing efforts are being made by the government at various levels (especially of Regione Campania) to reduce the population living in the red zone, by demolishing illegally constructed buildings, establishing a national park around the upper flanks of the volcano to prevent the erection of further buildings and by offering financial incentives to people for moving away. One of the underlying goals is to reduce the time needed to evacuate the area, over the next 20 or 30 years, to two or three days.
The volcano is closely monitored by the Osservatorio Vesuvio in Naples with extensive networks of seismic and gravimetric stations, a combination of a GPS-based geodetic array and satellite-based synthetic aperture radar to measure ground movement, and by local surveys and chemical analyses of gases emitted from fumaroles. All of this is intended to track magma rising underneath the volcano. No magma has been detected within 10 km of the surface, and so the volcano is classified by the Observatory as at a Basic or Green Level” [Wikipedia]

List of the eruptions

79 AD, 172, 203, 222, possibly 303, 379, 472, 512, 536, 685, 787, around 860, around 900, 968, 991, 999, 1006, 1037, 1049, around 1073, 1139, 1150, and there may have been eruptions in 1270, 1347, and 1500.The volcano erupted again in 1631, six times in the 18th century, eight times in the 19th century (notably in 1872), and in 1906, 1929, and 1944. There has been no eruption since 1944, and none of the post-79 eruptions were as large or destructive as the Pompeian one.

Vesuvius erupting videos

Mount Vesuvius erupting in 1938 – “The Vesuvius is in front of me. Now it is blazing and smoking. What an extraordinary sight! imagine an enormous firework that does not stop for even a minute” Nicolaj V. Gogol’, 1838

Mount Vesuvius erupting in 1944