Fig. 12b shows the associated non-dimensional cliff toe recession
rates. Subtle fluctuations in the future rates of retreat of the cliff toe
can be attributed to the vertical changes in material strength and interactions
with sea-level rise. For example, a 1 mm/yr sea-level rise corresponds
to a change in material strength (with respect to MSL) within
the heterogeneous 1 m layers every 1000 yrs. This is reflected in the
non-dimensional retreat rate; between years 1000 and 2000 a resistant
layer is present; however, between years 2000 and 3000 aweaker layer
is present and a rise in the retreat rate is apparent. The effect reduces
with faster rates of sea-level rise, owing to the limited period of time
that a given MSL has to interact with the anomalous layers. However,
this also depends on the thickness of the layers encountered.