A global dataset of Holocene reef morphometrics to improve numerical modelling of coral reef development

<div spellcheck="true" aria-live="assertive"><span>Coral </span><span>reef construction</span><span> results from interactions between the biosphere, hydrosphere and lithosphere. Reefs </span><span>constructed d</span><span>uring Quaternary sea-level variations and d</span><span>isplaced</span><span> by </span><span>rock uplift</span><span> produce stair-cased morphologies called reefal sequences. The stratigraph</span><span>y</span><span> and morpholog</span><span>y</span><span> of these sequences is </span><span>often </span><span>used </span><span>to infer</span><span> eustatic variations and vertical deformation.</span></div><div spellcheck="true" aria-live="assertive"></div><div aria-live="assertive"><span>Because </span><span>few coral terraces have been</span><span> precisely</span><span> dated</span><span> and </span><span>high resolution topo</span><span>-</span><span>bathymetry </span><span>is</span><span> scarce </span><span>along most coastlines</span><span>, morphostratigraph</span><span>ic</span> <span>interpretations </span><span>of reefal sequences</span><span> usually seek to constrain only the elevation and age of </span><span>r</span><span>elative </span><span>s</span><span>ea</span><span> l</span><span>evel highstands and average rate of vertical deformation</span><span>. Numerical modelling of reef development </span><span>can </span><span>help </span><span>elucidate </span><span>the </span><span>continuous </span><span>evolution of </span><span>coral</span><span> reef</span><span>s</span><span> through glacio-eustatic cycles.</span></div><div spellcheck="true" aria-live="assertive"></div><div spellcheck="true" aria-live="assertive"><span>How</span><span>e</span><span>ver,</span><span> controls on coral reef growth and morphology are still strongly debated.</span><span> E</span><span>ustatic variations, vertical deformation of the lithosphere, geometry of the accom</span><span>m</span><span>odation space, ecology of the reef, temperature, wave regime, turbidity </span><span>and other factors may all affect reef type (e.g., barrier or fringing), volume and geometry.</span></div><div spellcheck="true" aria-live="assertive"></div><div aria-live="assertive"><span>In order to </span><span>quantify</span><span> controls</span><span> on coral reef development</span><span>, we </span><span>compiled</span><span> a global dataset </span><span>of</span><span> coral reef morphometrics</span><span> from satellite imagery</span><span> a</span><span>nd measurements of </span><span>potential controlling factors </span><span>(e.g., </span><span>slope of the bedrock, rate of vertical deformation, wave power, sea-surface temperature, reef growth rate</span><span>)</span><span>.</span></div><div spellcheck="true" aria-live="assertive"></div><div aria-live="assertive"><span>Our first results highlight a strong </span><span>control </span><span>of the geometry of the accommodation space </span><span>on modern reefs morphology, especially on the reef type and the location of the reef crest. This geometry results from the </span><span>combination of the in</span><span>i</span><span>tial topography and antecedent constructions, which result from the interactions between eustatic variations, rate of vertical deformation and reef growth. A vast majority of barrier reefs, as well as the widest reef complexes, are located on antecedent reef platforms reoccupied during periods of sea-level rise.&#160;</span></div><div spellcheck="true" aria-live="assertive"></div><div aria-live="assertive"><span>Conclusions arising from this study will he</span><span>l</span><span>p validate our reef growth modelling, as well as its temporal and spatial resolution. This model could then not only improve the interpretation of the morphostratigraphic record, but also </span><span>clarify</span><span> the ability of coral reefs to keep-up with the future sea-level rise</span><span> and protect coastlines from </span><span>wave erosion.</span></div><div spellcheck="true" aria-live="assertive"></div><div spellcheck="true" aria-live="assertive"></div>