Experimental Design for Solid Block and Granular Submarine Landslides: A Unified Approach

Abstract

Dynamics of submarine landslides and the subsequent generation of surface waves are important topics in current tsunami research. As a part of our studies, we are developing numerical models for landslides as well as conducting laboratory experiments of solid block and granular landslides. This paper is a presentation of the methodologies of the experiments, which were conducted in two phases. The first phase followed the convention of previous investigators and used a semi-elliptical solid block on a 15° slope as a simplified test case. The second phase was an exploration of a wider range of phenomena in a larger parameter space than that undertaken by previous investigators within a single experimental framework. Phenomena under consideration included wave dynamics in the near field and far field regions, wave run up onto the shore, landslide center-of-mass motion, dilation, shape evolution, and internal particle motion as well as velocity distribution in the water column. The parameter space included variation of landslide density, volume, initial submergence, initial shape and deformability (i.e., solid blocks as well as granular material slides); this large parameter space was made tractable through the selection of a statistically balanced experimental design. The second phase also employed three unique measurement techniques: wave height measurement by laser induced fluorescence (LIF), landslide particle tracking using ultraviolet light, and particle tracking velocimetry (PTV) in the water column using visible light. The significance of the study lies in the variety of phenomena under consideration, the size of the parameter space, and in the unique methodology contained in a single experimental framework. Representative examples of each type of data that were produced during the study are also provided to round out this methodological description.