Fig. 2: Across-shore distribution of cosmogenic ¹⁰Be concentrations.

a Raw measured concentrations ± AMS measurement error and background uncertainty propagating in quadrature (Supplementary Note 1); dashed line delimits concentration due to deep muon production (geological inheritance); grey shadow (secondary axis) represents the elevation distribution across the profile indicated in Fig. 1b; grey lines indicate tidal levels: MHWS = 2.59-m AOD: mean high water level of spring tides; MHWN = 1.50-m AOD: mean high water level of neap tides; MLWN = −0.75-m AOD: mean low water level of neap tides; MLWS = −2.01-m AOD: mean low water level of spring tides (https://www.ntslf.org/). b Measured concentrations corrected for geological inheritance (concentration at #0 subtracted from raw measurements) ± AMS measurement error and background- and inheritance uncertainties propagating in quadrature (Supplementary Note 1) and those modelled using the scenario of steady cliff retreat rate of 4.5 ± 0.63 cm yr⁻¹ and profile-parallel coastal erosion (solid line and red error envelope). Dashed line and grey error envelope represent modelled concentrations, including the rate of step back-wearing (mean ± standard deviation). Vertical blue lines and boxes indicate major influences on relative sea level at the study location.