Transient and persistent shoreline change from a storm

[1] There is disagreement as to whether shoreline position eventually recovers from large storms. In an earlier paper we showed that statistical modeling of historical shoreline data was improved by including large storms in the model via a transient storm function. Here we show that, at shorter timescales of months to years, modeling of the shoreline at Assateague Island, MD is improved by a storm model with both transient and persistent components. We find that the shoreline recovers from the storm rapidly, almost within a year, but that the recovery is only partial, despite anthropogenic reconstruction of a pre-existing berm. The long-term trend of a shoreline (whether erosive, accretive, or stationary) can thus be regarded as the cumulative persistent component of successive storms, although most long-term data sets are too temporally sparse to make such a parameterization more useful than a steady long-term rate.