IAVCEI 2013 Scientific Assembly - July 20 - 24, Kagoshima, Japan
Forecasting Volcanic Activity - Reading and translating the messages of nature for society

3P1_3C-O21

Room A5

Date/Time: July 23 16:30-16:45

A preliminary evaluation of the impact of pyroclastic flows using TITAN2D at theBaekdusan volcano according to three different scenarios
Sung-Hyo Yun1 , Angelo Paone1 , Giovanni Macedonio2 , Jeong Hyun Lee1 , Sun Kyeong Kim1 , Yun
Jeong Kim1
1Department of Earth Science Education, Pusan National University, South Korea, 2 Osservatorio
Vesuviano, Istituto Nazionale di Geofisica e Vulcanologia, Napoli, Italy
E-mail: yunsh@pusan.ac.kr

The Baekdusan volcano was formed by three stages of activity: (a) a basalt shield(aging between 2.77 and0.31Ma), (b) a trachytic comendite stratocone(aging between 1.19 and 0.02 Ma), (c) a trachyte-comenditite
ignimbrite deposits(aging between 20 ka up to the present). Volcanic seismicity, ground deformation, and volcanic
gas geochemistry yields new evidence for magmatic unrest of the volcano between 2002 and 2006. The monitoringdata suggest that the Mt. Baekdusan is a potentially active volcano and close attention is needed. One ofthe possibly treat of this volcano is the pyroclastic flow volcanic hazard. In order to evaluate the pyroclastic
flow emplacement on this hazardous volcano, we use Titan2d code. It is based on a depth-averaged model for
an incompressible granular material, governed by Coulomb-type friction interactions. The governing equations
are obtained by applying conservation laws to the incompressible continuum, and then taking advantage of theshallowness of the flows to obtain simpler depth-averaged representations. The motion of the material is considered
to be gravitationally driven and resisted by both internal and bed friction forces. The resulting hyperbolic systemof equations is solved using a finite-volume scheme with a second-order Godunov solver. The DEM file (UTM
easting, UTM northing and elevation in meters) must be properly configured to operate with TITAN2D throughthe use of Grass GIS Software. The other input parameters used are: volume(5-10x107 m3, 1x109 m3, 2x1010m3) of a vertical cylinder pile(maximum height, major and minor axes), center of initial volume(the location of theinitial pile center are the vents of the 1903, 1702, 1668, Millennium eruptions), several orientation angle of theinitial pile were selected, internal friction angle(25-30 degree), bed friction angle(16-25 degree).The pyroclastic
flow run-out calculated in the field are small(3000 m, 1903 eruption) intermediate(5000 m, 1668-1702 eruptions),
large(6-70000 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, 1702, 1668, Millenniumeruptions) following the recent volcanic history of Baekdusan volcano. These eruptions brace all the possibly
explosive eruptive scenarios that can occur at Baekdusan volcano in the future. Preliminarily, the 1903 type
scenario has been performed, according to the vent location, the flow moves in diverse direction(NE, SE) witha thickness of 3 m, if the vent is center of the caldera the flow fills the caldera with a thickness of 5 m. The modelingof the other two scenario are in progress.
Acknowledgments : This research was supported by a grant (NEMA-BAEKDUSAN-2012-1-2) from the Volcanic
Disaster Preparedness Center sponsored by the National Emergency Management Agency of Korea©IAVCEI 2013 Scientific Assembly. All rights reserved.

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