Houser (2009) Summary of beach-dune interactions Flashcards
Most barrier islands and spits are in a state of transgression (land- ward retreat), why is this?
In response to a combination of eustatic sea-level rise and local land subsidence.
What happens to barrier islands during extreme storms?
Barrier islands transgress during extreme storms capable of breaching the fronting dunes and distributing sediment to the back of the island in the form of washover fans.
What does the redistribution of sediment during an extreme storm and the rate of island transgression depend on?
The height and alongshore extent of coastal dunes relative to the elevation of the storm surge.
What does storm erosion of the backshore and dunes lead to?
A scarped seaward dune slope that promotes sediment transport to the lee slope and the migration of the dune landward.
What does an increase in sea mean for the migration of the the nearshore and beach profile?
The landward migration of the nearshore and beach profile, creating the potential for the dune system to retreat landward without loss of height.
What does migration of the beach dune system require?
Sediment eroded offshore by the storm surge to be delivered first to the beachface by nearshore (surf and swash) processes and then transported to the back- shore by the wind.