Landslide-tsunamis (impulse waves)

Introduction

Landslide-tsunamis or impulse waves are large water waves generated by landslides, rock falls, snow avalanches, glacier calving or meteoroids impacting into a water body. The most devastating examples include the 1958 Lituya Bay case where a run-up height of 524 m was observed, and the 1963 Vaiont case in Northern Italy, where a dam was overtopped by more than 70 m resulting in about 2,000 casualties. Dr Heller conducts generic physical model tests to predict these extreme waves, he provides benchmark test cases to the numerical community and he also conducts numerical simulations. He established the impulse product parameter P, which is believed to be the most universal parameter for landslide-tsunamis prediction, and he was the lead author of a hazard assessment manual which is now widely applied to predict the effects of impulse waves in lakes, reservoirs, fjords and the sea.

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Home     Students     Wave energy conversion     Landslide-tsunamis     NERC project     Scale effects     Ski jump hydraulics     Further research    Downloads     Publications

Personal research website of Dr Valentin Heller

Generic empirical equations and numerical benchmark test cases

Fig. 1. Photo sequence of a physical landslide-tsunami test in a wave flume: (a,b,c) granular impact, impact crater formation and primary impulse wave generation and (d,e,f) propagation; the wave characteristics are measured with wave gauges and PIV (Heller and Hager 2010)

This research was conducted during his PhD project under a Swiss National Science Foundation grant. Generic empirical equations to predict landslide-tsunamis/impulse waves in both the slide impact and wave propagation zones were developed based on physical model tests. Granular slide materials generated impulse waves in a rectangular wave channel as shown in Fig. 1. Seven governing parameters were varied including the still water depth, the slide thickness, the slide impact velocity, the bulk slide volume, the bulk slide density, the slide impact angle and  the grain diameter. These governing parameters were arranged to the impulse product parameter P. A priori unknown wave parameters such as maximum wave amplitude, height and period and their evolution with propagation distance were expressed as a simple function of P (Heller and Hager 2010).

Selected publications

Journals

Heller, V., and Hager, W.H. (2014). A universal parameter to predict landslide-tsunamis? Journal of Marine Science and Engineering 2(2):400-412 (http://dx.doi.org/10.3390/jmse2020400).

Heller, V., Spinneken, J. (2013). Improved landslide-tsunami predictions: effects of block model parameters and slide model. Journal of Geophysical Research-Ocean 118(3):1489-1507 (http://dx.doi.org/10.1002/jgrc.20099).

Heller, V., Moalemi, M., Kinnear R.D., Adams, R.A. (2012). Geometrical effects on landslide-generated tsunamis. Journal of Waterway, Port, Coastal and Ocean Engineering 138(4):286-298 (http://dx.doi.org/10.1061/(ASCE)WW.1943-5460.0000130).

Watt, S.F.L., Talling, P.J., Vardy, M.E., Heller, V., Hühnerbach, V., Urlaub, M., Sarkar, S., Masson, D.G., Henstock, T.J., Minshull, T.A., Paulatto, M., Le Friant, A., Lebas, E., Berndt, C., Crutchley, G.J., Karstens, J., Stinton, A.J., Maeno, F. (2011). Combinations of volcanic-flank and seafloor-sediment failure offshore Montserrat, and their implications for tsunami generation. Earth and Planetary Science Letters 319-320:228-240 (http://dx.doi.org/10.1016/j.epsl.2011.11.032).

Heller, V., Hager, W.H. (2011). Wave types in landslide generated impulse waves. Ocean Engineering 38(4):630-640 (http://dx.doi.org/10.1016/j.oceaneng.2010.12.010).

Fuchs, H., Heller, V., Hager, W.H. (2010). Impulse wave run-over: experimental benchmark study for numerical modelling. Experiments in Fluids 49(5):985-1004 (http://dx.doi.org/10.1007/s00348-010-0836-x).

Heller, V., Hager, W.H. (2010). Impulse product parameter in landslide generated impulse waves. Journal of Waterway, Port, Coastal, and Ocean Engineering 136(3):145-155 (http://dx.doi.org/10.1061/(ASCE)WW.1943-5460.0000037).

Heller, V., Hager, W.H., Minor, H.-E. (2008). Scale effects in subaerial landslide generated impulse waves. Experiments in Fluids 44(5):691-703 (http://dx.doi.org/10.1007/s00348-007-0427-7).

Heller, V., Unger, J., Hager, W.H. (2005). Tsunami Run-up – A hydraulic perspective. Journal of Hydraulic Engineering 131(9):743-747 (http://dx.doi.org/10.1061/(ASCE)0733-9429(2005)131:9(743)).

Others

Heller, V., Rogers, B. (2015). Subaerial landslide-tsunami generation with a rigid slide in a channel (2D) and basin (3D). SPH benchmark test case 11, online publication, SPH European Research Interest Community SPHERIC website (online http://spheric-sph.org/validation-tests).

Heller, V. (2017). Tsunamis due to ice masses - Different calving mechanisms and linkage to landslide-tsunamis. Data storage report of HYDRALAB+ test campaign (online http://hydralab.eu/research--results/ta-projects/project/hydralab-plus/11/).

Heller, V. (2009): Subaerial landslide generated impulse waves in a wave channel. SPH benchmark test case 7, online publication, SPH European Research Interest Community SPHERIC website (online http://spheric-sph.org/validation-tests).

Heller, V., Hager, W.H., Minor, H.-E. (2009). Landslide generated impulse waves in reservoirs - Basics and computation. VAW Mitteilung 211, Boes, R. ed. ETH Zurich, Zurich (http://www.vaw.ethz.ch/en/the-institute/vaw-reports/2000-2009.html).

Heller, V. (2007). Landslide generated impulse waves - Prediction of near field characteristics. PhD Thesis 17531, ETH Zurich, Zurich (http://e-collection.ethbib.ethz.ch/view/eth:30012).

 

A project at Imperial College London investigated three block model parameters commonly ignored in predictive empirical equations based on block slides. The wave features were again predicted as a simple function of P. Landslide-tsunamis generated with granular and block slides were systematically compared. The quite surprising results were published in Heller and Spinneken (2013).

Impulse product parameter P

Numerical benchmark test cases

Numerical simulations, e.g. based on Smoothed Particle Hydrodynamics SPH, are nowadays able to predict landslide-tsunamis well. Such numerical predictions may be the main method in the near future, once problems such as excessive computational costs are overcome. In order to calibrate and validate numerical simulations, physical model tests can provide high quality data under well defined conditions. Several physical benchmark test cases were provided to the numerical community which can be found on the SPHERIC website, in Heller (2007) and in Fuchs et al. (2010).

More details about landslide-tsunamis (impulse waves) research are available under the section NERC project.

Last modified: 16.10.2017

A hazard assessment manual (Heller et al. 2009) for subaerial landslide generated impulse waves/landslide-tsunamis was developed (Swiss Federal Office of Energy SFOE grant). Generic empirical equations based on the impulse product parameter P were combined with the results of other physical model studies addressing the effects of impulse waves (Fig. 2). The run-up height, loading on dams and the overtopping volume can be estimated simply as a function of the slide parameters, the hill slope angle and the water depth. The manual was applied to various cases in Albania, Australia, Austria, Canada, France, Switzerland and Turkey. The English and German versions including spread sheets in Excel can be downloaded in the downloads section.

 

Hazard assessment manual

Fig. 2. Three phases covered by the hazard assessment manual: slide impact with wave generation, wave propagation with wave transformation and impact and run-up of the impulse wave with load transfer to the dam and, potentially overtopping of the dam (Heller et al. 2009)

Ice-tsunamis

Fig. 3. Ice-tsunami experiment in the 50 m x 50 m wave basin at Deltares, in Delft

“Ice-tsunamis” are a special case of landslide-tsunamis where an ice mass impacts into a water body. This type of tsunami is frequently observed at glacier terminuses in Greenland and many other ice covered regions in the world. Some of these calving ice masses result in extreme events, generating tsunamis with heights in the order of tens of meters or even larger. These ice-tsunamis are hazardous for human, resulted in many casualties and further threaten the shipping and Oil & Gas industries.

Dr Heller is the project leader of the EU funded HYDRALAB+ project “Tsunamis due to ice masses: Different calving mechanisms and linkage to landslide-tsunamis” where he together with six project partners from ETH Zurich, TU Braunschweig, TU Delft, the University of Innsbruck and the University of Nottingham accessed the 50 m × 50 m Delta wave basin at Deltares, Delft, in August 2017 (Fig. 3). Ice-tsunamis generated by a wide range of ice calving scenarios were investigated in this measurement campaign to enhance our physical understanding in ice-tsunamis and to calibrate and validate currently ongoing numerical simulations. Some news articles about the experiments were published in the Dutch newspaper De Volkskrant and online on the Waterforum and Kennislink.