Wave Driven Dune Growth

Having spent hundreds of hours in the field - you come to learn a lot about how natural systems behave. However, there are always some phenomena that are less intuitive than others. Despite having seen the process showing up in field data numerous times, it took quite some time to convince myself that (in certain morphologic settings) huge waves dont necessarily translate to erosion. As it turns out, during large wave events, there are corresponding increases in the long wave (infragravity, IG) energy which can actually contribute to accretive conditions for portions of the profile. During individual swash events more sediment is entrained on the uprush of swash than on the backrush - leading to the potential for deposition from infragravity swash on high portions of the beach. In the case that IG swash reaches the dune toe, but not too far above the dune toe, this process can actually contribute to dune growth. Pretty cool stuff. 

When you know this happens, it turns out that there is alot of compelling evidence that this process is relatively widespread throughout the Pacific Northwest USA based on the low gradient beach slopes. However, using both data and numerical models - the relative roles of both environmental and subtidal/subaerial morphology on wave driven dune growth are further explored. 

I spent way too much time on this "side project" of my PhD but I think it is quite fascinating. Most people that I tell about this process also don't believe me - but hopefully I can convince you. Although the process seems somewhat limited to end-member dissipative beaches, there are a lot of (potential) parallels to beach ridge formation and the geologic evolution of paleosystems - I would love to further pursue that topic if anyone is interested in collaborating?