Dr. Sung-Hyo Yun is a professor in the Department of Earth Science Education, Pusan National University (PNU), South Korea. He obtained a BSc from the College of Education, PNU, in 1980 and a MEd from the Graduate School, PNU, in 1982. Dr. Yun received his Ph.D. in Geology and Volcanology from the Graduate School, PNU, in 1987. Dr. Yun was the president of the Petrological Society of Korea and the Korean Society of Volcanic Hazards Mitigation.
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
The Pontine Plain was reclaimed by Fascists in the 1930s. The Plain morphology and sea level have persistently changed through the Pleistocene, and from the last post-glacial period, the coast started to retreat. The most recent hydrogeological maps (1957, 1977, and 2007) clearly show that water is saturating the plain, and this will cause serious mobility problems in the Pontine Plain in the future. Several hazards of the plain are listed in this chapter. These include volcanic, seismic, coastal erosion, and sinkhole hazards, as well as water contamination hazards (e.g., As F), which have increased the number of cancers. There is an urgent need for monitoring in the area (i.e., Latina).
Part of the book: Sedimentary Rocks and Aquifers