Cosmogenic exposure dating reveals limited long-term variability in erosion of a rocky coastline

Predicted sea-level rise and increased storminess are anticipated to lead to increases in coastal erosion. However, assessing if and how rocky coasts will respond to changes in marine conditions is difficult due to current limitations of monitoring and modelling. Here, we measured cosmogenic 10Be concentrations across a sandstone shore platform in North Yorkshire, UK, to model the changes in coastal erosion within the last 7 kyr and for the first time quantify the relative long-term eros0ive contribution of landward cliff retreat, and down-wearing and stripping of rock from the shore platform. The results suggest that the cliff has been retreating at a steady rate of 4.5 ± 0.63 cm yr−1, whilst maintaining a similar profile form. Our results imply a lack of a direct relationship between relative sea level over centennial to millennial timescales and the erosion response of the coast, highlighting a need to more fully characterise the spatial variability in, and controls on, rocky coast erosion under changing conditions. Predicted sea-level rise is widely anticipated to lead to increased coastal erosion, however, assessing how rocky coasts will respond to changes in marine conditions is difficult to constrain. Here, the authors find that a North Yorkshire rocky cliff has been eroding at a similar rate over the last 7 kyr, and they do not observe an increase in erosion rates in response to modern sea level rise.