Angelo Paone

By Angelo Paone and Sung-Hyo Yun

The Baekdusan volcano was formed through three stages of activity: (a) a basalt shield (aging between 22.6 and 1.48 Ma), (b) a trachytic comendite stratocone (aging between 1.19 and 0.02 Ma), (c) a trachyte-comendite ignimbrite deposits (aging from 20 ka till date). Volcanic seismicity, ground deformation, and volcanic gas geochemistry yield new evidence for magmatic unrest of the volcano between 2002 and 2006. The monitoring data suggest that Mt. Baekdusan is a potentially active volcano and that its close monitoring is needed. One of the possible volcanic hazards from this volcano is the pyroclastic density currents. In order to evaluate the small-scale pyroclastic flow emplacement scenario of the 1903 AD eruption, Titan2d mass-flow model is used. The 1668–1702 AD and the Millennium eruption are characterized by 4–5 and ~7 VEI, respectively. The Millennium eruption can be considered as the last colossal super-eruption like Tambora, and so Baekdusan volcano could have even a global effect. The parameters used are as follows: volume (5–10 × 107, 1 × 109, 2 × 1010 m3), the vents of the 1903, 1668–1702, and Millennium eruptions; the pyroclastic flow runout calculated in the field are small (3,000 m :1903 eruption), intermediate (5,000 m :1668–1702 eruptions), and large (7–80,000 m, Millennium eruption). The initial velocities (m/s) range from 50 (1903 eruption) to as high as 300 (Millennium eruption). The input parameters have constructed three scenarios (1903, 1668–1702, and Millennium eruptions) following the recent volcanic history of Baekdusan volcano. These eruptions embrace all the possibly explosive eruptive scenarios that can occur at Baekdusan volcano in the future. The 1903 type scenario has been performed; according to the vent location, the flow moves in diverse directions (NE, SE) with a thickness of 3 m, and if the vent is the center of the caldera the flow fills the caldera with a thickness of 5 m. The emplacement of the 1668–1702 AD scenarios will involve at least two populated cities nearest to Baekdusan volcano. The scenario of the Millennium eruption will be much more severe and it will hit all the cities and towns within a range of 80 km. The impact will be from regional to global. This, however, is an underestimation of the runout for the diluted pyroclastic density currents.

Part of the book: Updates in Volcanology

By Angelo Paone

Somma-Vesuvius is a quiescent stratovolcano with a probability of Plinian style volcanic reactivation. Its stratigraphy is well known in the last 40 ka BP. The volcanic products that are part of the Somma caldera are poorly studied. Conversely, younger products have been deeply studied together with the AD 79 Plinian eruption. The impact of a Plinian eruption has been studied and summarised here. A simplified scheme is presented from what we can understand the volcanic hazard and risk that the volcano poses to the greater Neapolitan population. In the last 40 years, the demography around the Somma-Vesuvius volcano has increased; consequently, the volcanic risk has increased. It would seem that the Italian Civil Protection (ICP) has not influenced the population and the Italian authority with their massive work around Somma-Vesuvius (red zone). People still continue to build houses. Nowadays, the Somma-Vesuvius volcano does not seem to threaten people or the people that live around Vesuvius are not afraid of the volcano. But as it is usual just in this moment that the work done and to be done must be speared to all Neapolitan people, working in the school to reach the family. People around Somma-Vesuvius tend to neglect the volcanic risk appearing around Vesuvio. So ICP, all must be much more attend about the behaviour of this Hazardous volcano.

Part of the book: Forecasting Volcanic Eruptions