\documentclass[a4paper, twocolumn]{article} \usepackage{polyglossia} \usepackage{authblk} \usepackage[sfdefault]{inter} \setmainlanguage{english} \usepackage[ backend=biber, style=iso-authoryear, sorting=nyt, ]{biblatex} \bibliography{library} \title{Analysis of the displacement of a large concrete block under an extreme wave} \author[1]{Edgar P. Burkhart} \author[*,1]{Stéphane Abadie} \affil[1]{Université de Pau et des Pays de l’Adour, E2S-UPPA, SIAME, France} \affil[*]{Corresponding Author, stephane.abadie@univ-pau.fr} \begin{document} \maketitle \section{Introduction} % Displacement of blocks studies Displacement of large blocks or boulders by waves is an interesting phenomenon in the study of extreme historical coastal events. The existence of block deposits at unusual heights can be a clue to past events such as extreme storms or tsunamis. For instance, \textcite{cox2018} studied coastal deposits on the coast of Ireland in relation to the storms from winter 2013--2014, and extracted criteria for analysing such deposits. Similarly, \textcite{shah2013} found boulder deposits on the mediterranean coast to be evidence of extreme storms in the Little Ice Age. % Need for analytical equations In order for those studies to be possible, analytical criterias are needed in order to ascertain the cause of the displacement of a block. \textcite{nott1997,nott2003} proposed a set of equations that have been widely used for that purpose. Those equations rely on an equilibrium relation between the lift force produced by a wave and restraining forces depending on the initial setting of the block, allowing to extract a minimal flow velocity necessary for movement initiation. A parametrisation of waves depending on their source is also used to provide minimal wave heights depending on the type of scenario --- wave or tsunami. Those equations were later revised by \textcite{nandasena2011}, as they were found to be partially incorrect. A revised formulation based on the same considerations was provided. The assumptions on which \citeauthor{nott2003, nandasena2011} are based were then critisized by \textcite{weiss2015}. In fact, according to them, the initiation of movement is not sufficient to guarantee block displacement. \textcite{weiss2015} highlights the importance of the time dependency on block displacement. A method is proposed that allows to find the wave amplitude that lead to block displacement. % Lack of observations -> observation Whether it is \textcite{nott2003}, \textcite{nandasena2011} or \textcite{weiss2015}, all the proposed analytical equations suffer from a major flaw; they are all based on simplified analytical models and statistical analysis. Unfortunately, no block displacement event seems to have been observed directly in the past. In this paper, we study such an event. In february 2017, a 50T concrete block was dropped by a wave on the crest of the Artha breakwater. Luckily, the event was captured by a photographer, and a wave buoy located 1.2km offshore captured the seastate. Information from the photographer allowed to establish the approximate time at which the block displacement occured. The goal of this paper is to model the hydrodynamic conditions near the breakwater that lead to the displacement of the 50T concrete block. % Modeling flow accounting for porous media Several approaches can be used when modelling flow near a breakwater. \section{Results} \section{Discussion} \section{Methods} \printbibliography \end{document}