Waves in Estuaries

Malcolm Green gave a public talk on “Waves in Estuaries” at the offices of MetOcean Solutions, Raglan, on Friday November 11.

The rise and fall of the tide is the most obvious physical feature of any estuary, and you would be right in concluding from that that the tide is the prime mover of water, salt, heat, nutrients and the like. But, that is not necessarily the case for sediments – in most of our North Island estuaries, waves move sediments, and the things that are attached to sediments. My aim in this talk is to convince you that waves in estuaries are both important and interesting. I will talk a lot about patterns in waves in time and space, and how these drive corresponding patterns in sediment resuspension and transport. I will show some results from an exploratory model that shows how suspended sediments might hyperconcentrate in the “turbid fringe”, and I will address the age-old question: which is more important, big waves or small waves? (The answer is: it depends.)