The response of coastal barrier islands to relative sea-level rise (SLR) is a long-debated issue. Over centennial and longer periods, regional barrier retreat is generally proportional to the rate of relative SLR. However, over multi-decadal timescales, this simplification does not hold. Field observations along the USA East Coast indicate that barrier retreat rate has at most increased by ~45% in the last ~100 years, despite a concurrent ≥200% increase in SLR rate. Using a coastal evolution model, we explain this observation by considering disequilibrium dynamics—the lag in barrier behaviour with respect to SLR. Here we show that modern barrier retreat rate is not controlled by recent SLR (last decades), but rather by the baseline SLR of the past centuries. The cumulative effect of the baseline SLR is to establish a potential retreat, which is then realized by storms and tidal processes in the following centuries. When SLR accelerates, the potential for retreat is first realized through removal of geomorphic capital. After several centuries, barrier retreat accelerates proportionally to the increase in SLR. As such, we predict a committed coastal response: even if SLR remains at present rates, barrier retreat in response to SLR will accelerate by ~50% within a century. The lag dynamics identified here are probably general, and should be included in predictions of barrier-system response to climate change.
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Georeferenced shapefiles of all digitized shorelines used in the Virginia Barrier Island shoreline-change analysis are available at https://doi.org/10.6073/pasta/69c10fdd9b27e43168f24ca8ef293dc7.
The model source code (written in MATLAB) is available on the Community Surface Dynamics Modeling System repository (https://csdms.colorado.edu/wiki/Model:CoastMorpho2D) and on GitHub (https://github.com/csdms-contrib/CoastMorpho2D).
Swift, D. J. P. Barrier-island genesis: evidence from the central atlantic shelf, eastern USA. Sediment. Geol. 14, 1–43 (1975).
Moore, L. J., List, J. H., Williams, S. J. & Stolper, D. Complexities in barrier island response to sea level rise: insights from numerical model experiments, North Carolina Outer Banks. J. Geophys. Res. Earth Surf. 115, F03004 (2010).
Stutz, M. L. & Pilkey, O. H. Global distribution and morphology of deltaic barrier island systems. J. Coast. Res. SI 36, 694–707 (2002).
Murray, A. B., Ashton, A. & Coco, G. in Sandy Beach Morphodynamics (eds Jackson, D. W. T. & Short, A. D.) 277–295 (Elsevier, 2020); https://doi.org/10.1016/B978-0-08-102927-5.00012-6
Houston, J. R. Sea-level acceleration: analysis of the world’s high-quality tide gauges. J. Coast. Res. 37, 272–279 (2021).
Hay, C. C., Morrow, E., Kopp, R. E. & Mitrovica, J. X. Probabilistic reanalysis of twentieth-century sea-level rise. Nature 517, 481–484 (2015).
Hapke, C. J., Kratzmann, M. G. & Himmelstoss, E. A. Geomorphic and human influence on large-scale coastal change. Geomorphology 199, 160–170 (2013).
Armstrong, S. B. & Lazarus, E. D. Masked shoreline erosion at large spatial scales as a collective effect of beach nourishment. Earth’s Future 7, 74–84 (2019).
Johnson, J. M. et al. Recent shifts in coastline change and shoreline stabilization linked to storm climate change. Earth Surf. Process. Landf. 40, 569–585 (2015).
Deaton, C. D., Hein, C. J. & Kirwan, M. L. Barrier island migration dominates ecogeomorphic feedbacks and drives salt marsh loss along the Virginia Atlantic Coast, USA. Geology 45, 123–126 (2017).
Lorenzo-Trueba, J. & Ashton, A. D. Rollover, drowning, and discontinuous retreat: distinct modes of barrier response to sea-level rise arising from a simple morphodynamic model. J. Geophys. Res. Earth Surf. 119, 779–801 (2014).
Moore, L. J., Patsch, K., List, J. H. & Williams, S. J. The potential for sea-level-rise-induced barrier island loss: insights from the Chandeleur Islands, Louisiana, USA. Mar. Geol. 355, 244–259 (2014).
Nienhuis, J. H. & Lorenzo‐Trueba, J. Can barrier islands survive sea-level rise? Quantifying the relative role of tidal inlets and overwash deposition. Geophys. Res. Lett. 46, 14613–14621 (2019).
Reeves, I. R. B., Moore, L. J., Murray, A. B., Anarde, K. A. & Goldstein, E. B. Dune dynamics drive discontinuous barrier retreat. Geophys. Res. Lett. 48, e2021GL092958 (2021).
Frederikse, T. et al. The causes of sea-level rise since 1900. Nature 584, 393–397 (2020).
Ciarletta, D. J., Lorenzo-Trueba, J. & Ashton, A. D. Mechanism for retreating barriers to autogenically form periodic deposits on continental shelves. Geology 47, 239–242 (2019).
Cowell, P. & Kinsela, M. in Barrier Dynamics and Response to Changing Climate (eds Moore, L. & Murray, A.) 243–275 (Springer, 2018); https://doi.org/10.1007/978-3-319-68086-6_8
Mariotti, G. Self-organization of coastal barrier systems during the Holocene. J. Geophys. Res. Earth Surf. 126, e2020JF005867 (2021).
Mellett, C. L. & Plater, A. J. in Barrier Dynamics and Response to Changing Climate (eds Moore, L. J. & Murray, A. B.) 57–89 (Springer, 2018); https://doi.org/10.1007/978-3-319-68086-6_2
Cowell, P. J. et al. The Coastal-Tract (Part 1): a conceptual approach to aggregated modeling of low-order coastal change. J. Coast. Res. 19, 812–827 (2003).
Finkelstein, K. & Ferland, M. A. in Sea-Level Fluctuations and Coastal Evolution Vol. 41 (eds Nummedal, D. et al.) 145–155 (SEPM, 1987).
Robbins, M. G., Shawler, J. L. & Hein, C. J. Contribution of longshore sand exchanges to mesoscale barrier-island behavior: insights from the Virginia Barrier Islands, US East Coast. Geomorphology 403, 108163 (2022).
Barnes, B. M. & Truitt, B. R. A. in Seashore Chronicles: Three Centuries of the Virginia Barrier Islands (eds Barnes, B. M. & Truitt, B. R.) 6–15 (Univ. Virginia Press, 1999).
Engelhart, S. E. & Horton, B. P. Holocene sea level database for the Atlantic coast of the United States. Quat. Sci. Rev. 54, 12–25 (2012).
Boon, J. D. & Mitchell, M. Nonlinear change in sea level observed at North American tide stations. J. Coast. Res. 31, 1295–1305 (2015).
Shawler, J. L. et al. Relative influence of antecedent topography and sea-level rise on barrier-island migration. Sedimentology 68, 639–669 (2021).
Duràn, O. & Moore, L. Barrier island bistability induced by biophysical interactions. Nat. Clim. Change 5, 158–162 (2015).
Rinaldo, T., Ramakrishnan, K. A., Rodriguez-Iturbe, I. & Vinent, O. D. Probabilistic structure of events controlling the after-storm recovery of coastal dunes. Proc. Natl Acad. Sci. USA 118, e2013254118 (2021).
Passeri, D. L. et al. The roles of storminess and sea level rise in decadal barrier island evolution. Geophys. Res. Lett. 47, e2020GL089370 (2020).
FitzGerald, D. M., Fenster, M. S., Argow, B. A. & Buynevich, I. V. Coastal impacts due to sea-level rise. Annu. Rev. Earth Planet. Sci. 36, 601–647 (2008).
Bruun, P. The Bruun rule of erosion by sea-level rise: a discussion on large-scale two- and three-dimensional usages. J. Coast. Res. 4, 627–648 (1988).
Cooper, J. A. G. & Pilkey, O. H. Sea-level rise and shoreline retreat: time to abandon the Bruun Rule. Glob. Planet. Change 43, 157–171 (2004).
Dean, R. G. & Houston, J. R. Determining shoreline response to sea level rise. Coast. Eng. 114, 1–8 (2016).
Thieler, E. R., Pilkey, O. H., Young, R. S., Bush, D. M. & Chai, F. The use of mathematical models to predict beach behavior for US Coastal Engineering: a critical review. J. Coast. Res. 16, 48–70 (2000).
Leatherman, S. P., Zhang, K. & Douglas, B. C. Sea level rise shown to drive coastal erosion. EOS Trans. Am. Geophys. Union 81, 55–57 (2000).
Passeri, D. L., Hagen, S. C. & Irish, J. L. Comparison of shoreline change rates along the South Atlantic Bight and Northern Gulf of Mexico coasts for better evaluation of future shoreline positions under sea level rise. J. Coast. Res. https://doi.org/10.2112/SI68-003.1 (2014).
Rosati, J. D., Dean, R. G. & Walton, T. L. The modified Bruun Rule extended for landward transport. Mar. Geol. 340, 71–81 (2013).
Zhang, K., Douglas, B. C. & Leatherman, S. P. Global warming and coastal erosion. Clim. Change 64, 41 (2004).
Wolinsky, M. A. & Murray, A. B. A unifying framework for shoreline migration: 2. Application to wave-dominated coasts. J. Geophys. Res. Earth Surf. https://doi.org/10.1029/2007JF000856 (2009).
Fenster, M. S., Dolan, R. & Morton, R. A. Coastal storms and shoreline change: signal or noise? J. Coast. Res. 17, 714–720 (2001).
de Schipper, M. A., Ludka, B. C., Raubenheimer, B., Luijendijk, A. P. & Schlacher, T. A. Beach nourishment has complex implications for the future of sandy shores. Nat. Rev. Earth Environ. 2, 70–84 (2021).
Gillett, N. P., Arora, V. K., Zickfeld, K., Marshall, S. J. & Merryfield, W. J. Ongoing climate change following a complete cessation of carbon dioxide emissions. Nat. Geosci. 4, 83–87 (2011).
Zhou, C., Zelinka, M. D., Dessler, A. E. & Wang, M. Greater committed warming after accounting for the pattern effect. Nat. Clim. Change 11, 132–136 (2021).
Cooper, J. A. G. & McKenna, J. Social justice in coastal erosion management: the temporal and spatial dimensions. Geoforum 39, 294–306 (2008).
Guza, R. & Thornton, E. Wave set-up on a natural beach. J. Geophys. Res. 86, 4133–4137 (1981).
Gomes da Silva, P., Coco, G., Garnier, R. & Klein, A. H. F. On the prediction of runup, setup and swash on beaches. Earth Sci. Rev. 204, 103148 (2020).
Goff, J., Swartz, J., Gulick, S., Dawson, C. & Ruiz de Alegria-Arzaburu, A. An outflow event on the left side of Hurricane Harvey: erosion of barrier sand and seaward transport through Aransas Pass, Texas. Geomorphology 334, 44–57 (2019).
Harter, C. & Figlus, J. Numerical modeling of the morphodynamic response of a low-lying barrier island beach and foredune system inundated during Hurricane Ike using XBeach and CSHORE. Coast. Eng. 120, 64–74 (2017).
Sherwood, C. R. et al. Inundation of a barrier island (Chandeleur Islands, Louisiana, USA) during a hurricane: observed water-level gradients and modeled seaward sand transport. J. Geophys. Res. Earth Surf. 119, 1498–1515 (2014).
Wesselman, D. et al. The effect of tides and storms on the sediment transport across a Dutch barrier island. Earth Surf. Process. Landf. 43, 579–592 (2018).
Davidson-Arnott, R., Bauer, B. & Houser, C. Introduction to Coastal Processes and Geomorphology (Cambridge Univ. Press, 2019); https://doi.org/10.1017/9781108546126
Durán, O. & Moore, L. J. Vegetation controls on the maximum size of coastal dunes. Proc. Natl Acad. Sci. USA 110, 17217–17222 (2013).
Houser, C. et al. Post-storm beach and dune recovery: implications for barrier island resilience. Geomorphology 234, 54–63 (2015).
Vinent, O. D., Schaffer, B. E. & Rodriguez-Iturbe, I. Stochastic dynamics of barrier island elevation. Proc. Natl Acad. Sci. USA 118, e2013349118 (2021).
Jerolmack, D. J. et al. Internal boundary layer model for the evolution of desert dune fields. Nat. Geosci. 5, 206–209 (2012).
Keijsers, J. G. S., Groot, A. V. D. & Riksen, M. J. P. M. Modeling the biogeomorphic evolution of coastal dunes in response to climate change. J. Geophys. Res. Earth Surf. 121, 1161–1181 (2016).
Davidson-Arnott, R. et al. Sediment budget controls on foredune height: comparing simulation model results with field data. Earth Surf. Process. Landf. 43, 1798–1810 (2018).
Cohn, N. et al. Exploring marine and aeolian controls on coastal foredune growth using a coupled numerical model. J. Mar. Sci. Eng. 7, 13 (2019).
Ciarletta, D. J., Shawler, J. L., Tenebruso, C., Hein, C. J. & Lorenzo-Trueba, J. Reconstructing coastal sediment budgets from beach- and foredune-ridge morphology: a coupled field and modeling approach. J. Geophys. Res. Earth Surf. 124, 1398–1416 (2019).
Blom, A., Arkesteijn, L., Chavarrías, V. & Viparelli, E. The equilibrium alluvial river under variable flow and its channel-forming discharge. J. Geophys. Res. Earth Surf. 122, 1924–1948 (2017).
Wolman, M. G. & Miller, J. P. Magnitude and frequency of forces in geomorphic processes. J. Geol. 68, 54–74 (1960).
Ortiz, A. C. & Ashton, A. D. Exploring shoreface dynamics and a mechanistic explanation for a morphodynamic depth of closure. J. Geophys. Res. Earth Surf. 121, 442–464 (2016).
We acknowledge L. J. Moore and P. C. Roos for constructive comments on an earlier version of the manuscript, and M. Robbins, G. D. Molino and E. A. Hein for assistance with shoreline-change analysis. This work is a contribution to IGCP Project 725 ‘Forecasting Coastal Change’ and is contribution 4097 of the Virginia Institute of Marine Science, William & Mary.
The authors declare no competing interests.
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Extended Data Fig. 1 Predicted barrier island retreat, emphasizing the response to storm surges.
Simulation with Ro = 1.5 mm/yr and Ri = 1.5 mm/yr (as in Supplementary Video 5), aimed to show the dune dynamics in the equilibrated regime (that is, without SLR acceleration). A) Ten transects (a-j) are considered. B) Temporal evolution of the barrier crest at these eight transects. Red dashed lines indicate the average elevation of islands in the VBI system in the “low state” (equal to the beach berm, here set equal to 0 m) and the “high state” (approximately 1.5 m above the beach berm). The arrows on transect “d” point to erosion occurring after a major storm in year 255.
Extended Data Fig. 2 Sensitivity analysis with respect to storm surges.
A) Comparison of dune height distribution for the case with Ro = Ri = 1.5 mm/yr, and with different scale parameters for the storm surge, for the case with Ro = Ri = 1.5 mm/yr. B) Prediction of barrier retreat for different scale parameters for the storm surge. Case with Ri = 1.5 mm/yr and Ri = 4 mm/yr (and Ro = 1.5 mm/yr).
Extended Data Fig. 3 Model validation through comparison with Dauphin Island (AL, USA).
Comparison of the measured bathymetry of Dauphin Island, Alabama (USA) and the analogue bathymetry recreated by the CoastMorpho2D. Rectangles indicate the region showed in Supplementary Fig. 11.
Extended Data Fig. 4 Model validation through comparison with Passeri’s model.
Comparison of simulated bathymetric changes at Dauphin Island, Alabama (USA) after 10 years under different SLR steps and storm regimes. A) Simulations based on Passeri et al. (2020) B) Simulations with CoastMorpho2D for a realistic analogue.
Extended Data Fig. 5 Shoreline-change predictions for various increased SLR rates Ri and for different wave regimes (Hs, Tp) and tidal ranges (r).
All results are shown for the case of Ro = 1.5 mm/yr (thus for the same equilibrated retreat rate Φo). For each scenario (that is, each combination of wave energy and tidal range), the relaxation time α is calculated as best fit between the simplified model (Eq. 1) and the CoastMorpho2D predictions.
Extended Data Fig. 6 Predicted topobathymetric changes attributed to autogenic variability and SLR rate increase.
A) Simulated topobathymetric changes after 100 years of evolution, starting from the equilibrated conditions with Ro = 1.5 mm/yr (Fig. 3A) and with an increase in SLR rate to Ri = 4 mm/yr. B) Simulated changes due to autogenic variability in the equilibrated regime (calculated as in A but by keeping Ri = Ro = 1.5 mm/yr). An example of lateral channel migration is denoted. C) Changes due only to the increased rate of SLR, calculated as the difference between panel B and A. Examples of accreting ebb-tidal deltas and deepening tidal channels are noted.
Extended Data Fig. 7 Barrier island retreat predictions using analytical lag model.
Comparison of the predicted retreat rate using the analytical lag model (Eq. S4) in the case with an instantaneous increase in SLR rate at year 1930, and the cases in which SLR rate increased gradually from 1930 to 1970, from 1930 to 2010, and from 1900 to 2010. In all cases SLR is increased from Ro = 1.5 mm/yr to either Ri = 4.5 mm/yr (left panels) or Ri = 6.0 mm/yr (right panels). Applied SLR rates are shown in the top panels and system-wide retreat rates in the bottom panels. The relaxation time is set equal to 170 years, which is representative for the VBI (Fig. 4).
Extended Data Fig. 8 Alongshore variability in shoreline migration along the Virginia Barrier Islands.
A) Map of long-term (1851–2017) shoreline-change rates along each transect; numbers in parentheses following island names are average island-wide shoreline change rates for the 1851–2017 period. B-D) Shoreline change rates for the full time period and sample years, plotted by transect number. Positive values indicate landward movement.
Extended Data Fig. 9 Long-term shoreline changes at selected sites in the Virginia Barrier Islands.
Examples of long-term (1851–2017) shoreline changes along migrational (Metompkin), rotational (Hog), and progradational (Fisherman’s) islands. Shown in lower graph are mean (± standard error) and 10-year running average shoreline-change rate for each of the three islands shown above. Positive values indicate landward movement. Esri “World Imagery”, accessed February 10, 2022. Earthstar Geographics (TerraColor NextGen) imagery. https://www.arcgis.com/apps/mapviewer/index.html?layers=10df2279f9684e4a9f6a7f08febac2a9.
Supplementary methods, Discussion, Figs. 1–19 and Tables 1 and 2.
Supplementary Video 1
Evolution of the system during the last 7,000 years, with SLR rate equal to 20 mm yr−1 during the first 2,000 years and equal to 1.5 mm yr−1 in the last 5,000 years.
Supplementary Video 2
Evolution of the system during the last 7,000 years, with SLR rate equal to 20 mm yr−1 during the first 2,000 years and equal to 1 mm yr−1 in the last 5,000 years.
Supplementary Video 3
Evolution of the system during the last 7,000 years, with SLR rate equal to 20 mm yr−1 during the first 2,000 years and to equal to 0.5 mm yr−1 in the last 5,000 years.
Supplementary Video 4
Starting from the equilibrated regime with a SLR rate of 1.5 mm yr−1 (end of Video 1), evolution during the following 500 years for a SLR rate equal to 0 mm yr−1.
Supplementary Video 5
Starting from the equilibrated regime with a SLR rate of 1.5 mm yr−1 (end of Video 1), evolution during the following 500 years for a SLR rate equal to 1.5 mm yr−1.
Supplementary Video 6
Starting from the equilibrated regime with a SLR rate of 1.5 mm yr−1 (end of Video 1), evolution during the following 500 years for a SLR rate equal to 4 mm yr−1.
Supplementary Video 7
Starting from the equilibrated regime with a SLR rate of 1.5 mm yr−1 (end of Video 1), evolution during the following 500 years for a SLR rate equal to 7 mm yr−1.
Supplementary Video 8
Starting from the equilibrated regime with a SLR rate of 1.5 mm yr−1 (end of Video 1), evolution during the following 500 years for a SLR rate equal to 10 mm yr−1.
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Mariotti, G., Hein, C.J. Lag in response of coastal barrier-island retreat to sea-level rise. Nat. Geosci. 15, 633–638 (2022). https://doi.org/10.1038/s41561-022-00980-9
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