Reef Sedimentary Accretion Model (ReefSAM): Understanding coral reef evolution on Holocene time scales using 3D stratigraphic forward modelling

Abstract

A detailed understanding of the development of coral reefs and their internal structure has important applications for predicting future reef trajectories in light of climate changes, petroleum exploration and reconstructing past environmental changes such as sea level. Numerical computer modelling provides a quantitative means of testing and understanding reef processes and better predicting past and future reef development. However, most existing carbonate stratigraphic forward models (SFMs) focus on the platform scale and several limitations in their simulation of important reef processes and reef-scale features (e.g. patch reefs, sand aprons) have been previously identified. We present the Reef Sedimentary Accretion Model (ReefSAM)-a new carbonate SFM designed to test new approaches to modelling processes important at the reef scale, with the goal of better simulating reef features and evolution at higher temporal and *Manuscript Click here to download Manuscript: MARGO6160_R2_clean.docx Click here to view linked References Barrett and Webster 2017-Marine Geology 2 spatial resolutions. Specific developments include a sediment transport model which calculates deposition based on a range of grain sizes, and additional controls on coralgal growth including wave energy and surface substrate specificity, and model outputs showing categorized paleo-conditions (composition, paleo-depth and paleoenergy) along with numerous quantitative measures for objective comparison of model results to real-world observational data, which is often more abundant for modern/Holocene reefs than buried ancient reefs Simulations of the well-studied Holocene One Tree Reef (OTR), in the southern Great Barrier Reef (GBR) showed improvements upon previous modelling attempts in both quantitative measures (e.g. lagoon size or reef sea level catch-up time), and ability to produce more realistic reefscale morphological features (e.g. lagoonal patch-reefs, mostly sand-filled lagoon) and reef development characteristics (e.g. transition from mostly vertical aggradation during sea level catch-up to horizontal progradation afterwards). Controls on reef maturity/lagoonal filling identified in previous modelling experiments were corroborated. Sensitivity testing also revealed a very high sensitivity to reef drowning. These results indicate the new modelling approaches are viable and provide a way forward for future Holocene reef evolution model development.

Exploring coral reef responses to millennial-scale climatic forcings: insights from the 1-D numerical tool pyReef-Core v1.0

“…Cabioch et al, 1999;Abbey et al, 2011;Dechnik et al, 2015). Several numerical models have been developed since the 1960s to investigate the evolution of carbonate systems; yet only recently have the complexity of biological interactions -specific to reefs -started to be addressed (Barrett and Webster, 2017;Clavera-Gispert et al, 2017).…”

“…Most recently, three software packages have been developed that represent important antecedents to the modelling effort described in this paper: CARBONATE-3D (C3D) (Warrlich et al, 2008), ReefSAM (Barrett and Webster, 2017), and SIMSAFADIM-CLASTIC (Clavera-Gispert et al, 2017). These models are 3-D and able to simulate hydrodynamic processes, sediment transport and biological production, but with varying degrees of realism.…”

“…lagoonal patch reefs and mostly sand infilled lagoons) that depends on environmental factors (Barrett and Webster, 2017). However, despite the added complexity, ReefSAM, like C3D, was found to have overly simplistic hydrodynamic and sediment transport models that were unable to simulate important, small-scale morphological features and feedbacks (Barrett and Webster, 2017).…”

Exploring coral reef responses to millennial scale climatic forcings: insights from a 1-D numerical tool pyReef-Core v1.0

“…In that sense, SFM addresses the short-comings of qualitative investigation techniques applied to carbonate systems (e.g., Cabioch et al, 1999;Abbey et al, 2011;Dechnik et al, 2015). Several numerical models have been developed since the 1960s to investigate the evolution of carbonate systems, yet only recently have the complexity of biological interactions -specific to reefs -started to be addressed (Barrett and Webster, 2017;Clavera-Gispert et al, 2017).…”

Bayesreef: A Bayesian inference framework for modelling reef growth in response to environmental change and biological dynamics

“…As a result, limited work has been done in modelling reef evolution. While some software and models of long-term interactions of organisms in a marine ecosystem exist [3], only recently has a specific software for coral reef modelling has been created [1,4].…”