The Tsunami Simulation Generated by ‘Anak Krakatau’ Volcano Flank Collapse using MIKE 21Hydrodynamics Flexible Mesh with Manning Number Variation

Hanah Khoirunnisa; Wahyu Hendriyono; Mardi Wibowo

doi:10.30871/jagi.v5i1.2288

Hanah Khoirunnisa Centre of Technology in Maritime Industrial Engineering, Indonesian Agency for the Assessment & Application of Technology (PTRIM - BPPT)
Wahyu Hendriyono Centre of Technology in Maritime Industrial Engineering, Indonesian Agency for the Assessment & Application of Technology (PTRIM - BPPT)
Mardi Wibowo Centre of Technology in Maritime Industrial Engineering, Indonesian Agency for the Assessment & Application of Technology (PTRIM - BPPT)

DOI: https://doi.org/10.30871/jagi.v5i1.2288

Keywords: Flank Collapse, Manning numbers, MIKE 21 Hydrodynamics Flexible Mesh (HD FM), Tsunami Arrival Time

Abstract

This study aims to calculate the tsunami investment and the estimated arrival time at several locations around the Sunda strait, caused by the December 2018 Krakatao's eruption. The propagation of the tsunami wave is simulated using MIKE 21 Hydrodynamics Flexible Mesh (HD FM). The spatial data consist of the bathymetry and topography of the Sunda Strait area and its surroundings, whilst assumptions are made on the tsunami source topology and its exact location. Several runs of the simulation are then conducted by varying the Manning Number, i.e. bed resistance values, at the tsunami source and throughout the simulation domain, which accordingly would influence the propagation speed, inundation, and arrival time. Smaller Manning's values, which correspond to increasing roughness, are applied at locations closer to the tsunami source. In this simulation, Manning's number ranges from 10 to 40 m^1/3s^-1. Surface elevation, still water depth, and u and v velocity components are generated from this simulation.

Downloads

Download data is not yet available.

References

Abadie, S.M., Harris, J.C., Grilli, S.T. and Fabre, R., 2012. Numerical modeling of tsunami waves generated by the flank collapse of the Cumbre Vieja Volcano (La Palma, Canary Islands): tsunami source and near field effects. Journal of Geophysical Research: Oceans, 117(C5).

Gayer, G., Leschka, S., Nöhren, I., Larsen, O. and Günther, H., 2010. Tsunami inundation modelling based on detailed roughness maps of densely populated areas. Natural Hazards and Earth System Sciences, 10(8), p.1679.

Giachetti, T., Paris, R., Kelfoun, K. and Ontowirjo, B., 2012. Tsunami hazard related to a flank collapse of Anak Krakatau volcano, Sunda Strait, Indonesia. Geological Society, London, Special Publications, 361(1), pp.79-90.

Grilli, S.T., Tappin, D.R., Carey, S., Watt, S.F., Ward, S.N., Grilli, A.R., Engwell, S.L., Zhang, C., Kirby, J.T., Schambach, L. and Muin, M., 2019. Modelling of the tsunami from the December 22, 2018 lateral collapse of Anak Krakatau volcano in the Sunda Straits, Indonesia. Scientific reports, 9(1), pp.1-13.

Hasan, M.M., Rahman, S.M. and Mahamud, U., 2015. Numerical Modeling for the Propagation of Tsunami Wave and Corresponding Inundation. IOSR J. Mech. Civil Eng, 12(2), pp.55-62.

Leschka, S., Pedersen, C. and Larsen, O., 2009, November. On the requirements for data and methods in tsunami inundation modelling–Roughness map and uncertainties. In Proc. of the South China Sea Tsunami Workshop, Penang, Malaysia (pp. 3-5).

Luger, S. and Harris, R.L., 2010, September. Modelling tsunami generated by earthquakes and submarine slumps using MIKE-21. In International MIKE by DHI conference, South Africa, Paper (p. P017).

Takabatake, T., Shibayama, T., Esteban, M., Achiari, H., Nurisman, N., Gelfi, M., Tarigan, T.A., Kencana, E.R., Fauzi, M.A.R., Panalaran, S. and Harnantyari, A.S., 2019. Field survey and evacuation behaviour during the 2018 Sunda Strait tsunami. Coastal Engineering Journal, pp.1-21.

Ward, S.N., 2001. Landslide tsunami. Journal of Geophysical Research: Solid Earth, 106(B6), pp.11201-11215.

Williams, R., Rowley, P. and Garthwaite, M.C., 2019. Reconstructing the Anak Krakatau flank collapse that caused the December 2018 Indonesian tsunami. Geology, 47(10), pp.973-976.

Williams, R., Rowley, P. and Garthwaite, M.C., 2019. Small flank failure of Anak Krakatau Volcano caused catastrophic December 2018 Indonesian tsunami.