In this page we provide material (contributions are welcome!) to help whoever is interested in learning more about coastal research. The movies and pictures can be used in class or in presentations. Please make a reference using the info provided.

Formation of sorted bedforms (regular waves and currents)

This model was originally developed by Brad Murray (Duke University) and Rob Thieler (USGS). The version in the movie results from modifications following a collaboration between Brad, Malcolm Green and Giovanni. The model was further improved by Evan Goldstein. The reference describing this simulation is:


Coco, G., Murray, A. B., & Green, M. O. (2007). Sorted bed forms as self‐organized patterns: 1. Model development. Journal of Geophysical Research: Earth Surface, 112(F3).

Formation of Rip Channels

Check out this great video from Bruno Castelle (University of Bordeaux). The video shows results of Bruno's numerical model of surf zone morphodynamics and rip channel formation. Bruno has done a lot of work on the topic and you should definitely check out his work. The key reference for this video is:

  •  Dubarbier, B., Castelle,  B., Ruessink, G., Marieu, V. (2017). Mechanisms controlling the  complete accretionary beach state sequence. Geophysical Research  Letters, 44 (11), 5645-5654.  

Rip currents at Tairua beach (New Zealand)

This video, prepared by NIWA and Karin Bryan (University of Waikato) consists of a sequence of orthorectified images. Each image is actually the average of 600 images collected each hour during daytime. The averaging process emphasizes the presence of sandbars (white areas, where waves break) and rip channels (area with no white). It's quite incredible how mobile the rips are.

Key reference:


Gallop, S. L., Bryan, K. R., Coco, G.,  & Stephens, S. A. (2011). Storm-driven changes in rip channel  pat

Formation of a tidal network

This vodeo was prepared by Zeng Zhou (Hohai University) at the time of his PhD in Spain.  The simulation tries to reproduce the laboratory experiments of the Padua group ( 

Stefanon, Luana, Luca Carniello,  Andrea D'Alpaos, and Andrea Rinaldo. "Signatures of sea level changes on  tidal geomorphology: Experiments on network incision and retreat." Geophysical Research Letters 39, no. 12 (2012).). The key reference is:


Zhou, Z., Olabarrieta, M., Stefanon,  L., D'Alpaos, A., Carniello, L., & Coco, G.

Beach Cusp Formation

Here is an old goodie, a simulation using a CA  model that reproduces beach cusp formation. Graphics and colours look old (hey, it was 1999!) but I think it could still be used in class.

If you need a reference, please use   

  • Coco, G., Huntley, D.A., and O’Hare, T.J. (2000) Investigation of a self-organisation model for beach cusp formation and development, Journal of Geophysical Research, 105(C9), 21991-22002.

Crescentic bars

Another 'vintage' video. This one shows the development of crescentic bars (or rip channels). Bottom plot shows the difference between actual and initial water depth  (once the perturbation is large enough, one can also see it on the top subplot). Useful reference:   

  • Caballeria, M., Coco, G., Falqués, A., and Huntley, D.A., 2002, Self-organization mechanisms for the formation of nearshore crescentic sand bars, Journal of Fluid Mechanics, 465: 379-410.

Ripple hysteresis

A video showing ripple evolution under step-change of wave condition. The power spectral density is derived from photos taken during the experiment. The dominant wavenumber indicates the dominant ripple spacing. 

Useful reference: 

  • Jin, C., Coco, G., Tinoco, R. O., Goldstein, E. B., & Gong, Z. (2019). Laboratory experiments on the role of hysteresis, defect dynamics and initial perturbation on wave-generated ripple development.