Runup and rundown generated by three-dimensional sliding masses

To study the waves and runup/rundown generated by a sliding mass, a numerical simulation model, based on the large-eddy-simulation (LES) approach, was developed. The Smagorinsky subgrid scale model was employed to provide turbulence dissipation and the volume of fluid (VOF) method was used to track the free surface and shoreline movements. A numerical algorithm for describing the motion of the sliding mass was also implemented. To validate the numerical model, we conducted a set of large-scale experiments in a wave tank of 104m long, 3.7m wide and 4.6m deep with a plane slope (1:2) located at one end of the tank. A freely sliding wedge with two orientations and a hemisphere were used to represent landslides. Their initial positions ranged from totally aerial to fully submerged, and the slide mass was also varied over a wide range. The slides were instrumented to provide position and velocity time histories. The time-histories of water surface and the runup at a number of locations were measured. Comparisons between the numerical results and experimental data are presented only for wedge shape slides. Very good agreement is shown for the time histories of runup and generated waves. The detailed three-dimensional complex flow patterns, free surface and shoreline deformations are further illustrated by the numerical results. The maximum runup heights are presented as a function of the initial elevation and the specific weight of the slide. The effects of the wave tank width on the maximum runup are also discussed.

[1]  J. Deardorff A numerical study of three-dimensional turbulent channel flow at large Reynolds numbers , 1970, Journal of Fluid Mechanics.

[2]  D. B. Kothe,et al.  Modeling High Density Ratio Incompressible Interfacial Flows , 2002 .

[3]  Eli A. Silver,et al.  The slump origin of the 1998 Papua New Guinea Tsunami , 2002, Proceedings of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences.

[4]  P. Heinrich,et al.  Nonlinear Water Waves Generated by Submarine and Aerial Landslides , 1992 .

[5]  Christopher J. Ruscher,et al.  A Field Survey of the 1946 Aleutian Tsunami in the Far Field , 2002 .

[6]  N. Ambraseys The seismic sea wave of July 9, 1956, in the Greek archipelago , 1960 .

[7]  Fumihiko Imamura,et al.  Landslide Tsunamis: Recent Findings and Research Directions , 2003 .

[8]  P. Leblond,et al.  The coupling of a submarine slide and the surface waves which it generates , 1992 .

[9]  D. B. Kothe,et al.  A SECOND-ORDER ACCURATE, LINEARITY-PRESERVING VOLUME TRACKING ALGORITHM FOR FREE SURFACE FLOWS ON 3-D UNSTRUCTURED MESHES , 1999 .

[10]  Steven N. Ward,et al.  Landslide tsunami , 2003 .

[11]  E. Novikov,et al.  Numerical simulation of the wake of a towed sphere in a weakly stratified fluid , 2002, Journal of Fluid Mechanics.

[12]  Lian Shen,et al.  Large-eddy simulation of free-surface turbulence , 2001, Journal of Fluid Mechanics.

[13]  Pengzhi Lin,et al.  Wave–current interaction with a vertical square cylinder , 2003 .

[14]  E. Okal T Waves from the 1998 Papua New Guinea Earthquake and its Aftershocks: Timing the Tsunamigenic Slump , 2003 .

[15]  R. L. Wiegel,et al.  Laboratory studies of gravity waves generated by the movement of a submerged body , 1955 .

[16]  T. Miloh,et al.  Tsunamis Induced by Submarine Slumpings off the Coast of Israel , 1976 .

[17]  L. Pratson,et al.  Source of the great tsunami of 1 April 1946: a landslide in the upper Aleutian forearc , 2004 .

[18]  C. W. Hirt,et al.  Volume of fluid (VOF) method for the dynamics of free boundaries , 1981 .

[19]  D. Yuk,et al.  Numerical modeling of submarine mass-movement generated waves using RANS model , 2006, Comput. Geosci..

[20]  J. Smagorinsky,et al.  GENERAL CIRCULATION EXPERIMENTS WITH THE PRIMITIVE EQUATIONS , 1963 .

[21]  Patrick J. Lynett,et al.  Analytical solutions for forced long waves on a sloping beach , 2003, Journal of Fluid Mechanics.

[22]  E. Okal Use of the mantle magnitudeMm for the reassessment of the moment of historical earthquakes , 1992 .

[23]  Lian Shen,et al.  Simulation of steep breaking waves and spray sheets around a ship: the last frontier in computational ship hydrodynamics , 2003, 2003 User Group Conference. Proceedings.

[24]  Efim Pelinovsky,et al.  Simplified model of tsunami generation by submarine landslides , 1996 .

[25]  T. S. Murty,et al.  Submarine slide‐generated water waves in Kitimat Inlet, British Columbia , 1979 .

[26]  W. Rider,et al.  Reconstructing Volume Tracking , 1998 .

[27]  E. Okal,et al.  Near-Field Survey of the 1946 Aleutian Tsunami on Unimak and Sanak Islands , 2003 .

[28]  Harry Yeh,et al.  Tsunamigenic Sea-Floor Deformations , 1997, Science.

[29]  B. Gutenberg Tsunamis and earthquakes , 1939 .

[30]  P. Moin,et al.  Approximate Wall Boundary Conditions in the Large-Eddy Simulation of High Reynolds Number Flow , 2000 .

[31]  Fumihiko Imamura,et al.  Tsunami in Papua New Guinea was as intense as first thought , 1999 .

[32]  H. Kanamori,et al.  A single-force model for the 1975 Kalapana, Hawaii, Earthquake , 1987 .

[33]  H. Kanamori,et al.  Source mechanism of the magnitude 7.2 Grand Banks earthquake of November 1929: Double couple or submarine landslide? , 1987 .

[34]  Philip Watts,et al.  Water waves generated by underwater landslides , 1997 .