FYFD

Tag: ocean waves

  • Featured Video Play Icon

    Testing Structures Against Hurricane Storm Surge

    When hurricanes hit coasts, they bring with them incredible storm surge, which puts buildings right in the middle of ocean waves. To understand how to better protect against those conditions, engineers use facilities like the Directional Wave Basin to create smaller-scale versions of hurricanes. In this Practical Engineering video, Grady visited during a test that compared two identical one-third-scale houses subjected to the same storm conditions–except that one house had an additional foot (3ft at real-scale) of elevation. The results are pretty spectacular.

    This isn’t a short video, but it’s well-worth a watch. I think Grady does a great job of explaining why engineers need (admittedly) expensive facilities like this one to help guide both engineering and regulatory decisions. (Video and image credit: Practical Engineering)

    Fediverse Reactions
  • Radiant Waves

    Radiant Waves

    Photographer Kevin Krautgartner captures the powerful waves of Western Australia from above. His latest series, Waves | Ocean Forces, features luminous turquoise waves, crystalline foam, and brilliant beaches. I could delight in staring at them for hours. Fortunately, he sells prints on his website! (Image credit: K. Krautgartner; via Colossal)

    Fediverse Reactions
  • A Rough Day

    A Rough Day

    Winds from the north made for wild conditions at Nazaré in Portugal. Photographer Ben Thouard caught these crashing waves in the late afternoon, when the low sun angle illuminated the spray of the surf. Every year teratons of salt and biomass move from the ocean to the atmosphere, much of it through turbulent wave action driven by the wind. Here, the wind rips droplets off of wave crests, but smaller droplets reach the atmosphere when bubbles–trapped underwater by crashing waves–reach the surface and burst. (Image credit: B. Thouard/OPOTY; via Colossal)

    Fediverse Reactions
  • Waves Over Sand Ripples

    Waves Over Sand Ripples

    Look beneath the waves on a beach or in a bay, and you’ll find ripples in the sand. Passing waves shape these sandforms and can even build them to heights that require dredging to keep waterways passable to large ships. To better understand how the sand interacts with the flow, researchers build computer models that couple the flow of the water with the behavior of individual sand grains. One recent study found that sand grains experienced the most shear stress as the flow first accelerates and then again when a vortex forms near the crest of the ripple. (Image credit: D. Hall; research credit: S. DeVoe et al.; via Eos)

    Fediverse Reactions
  • Predicting Sea States

    Predicting Sea States

    Transferring cargo between ships and landing aircraft on carriers requires predicting how the waves will behave for the next few minutes. That’s a notoriously difficult task for several reasons: rough seas can hide a ship radar’s view and the inherent nonlinearity of ocean waves means that they can occasionally coalesce unexpectedly large (“rogue“) waves, seemingly from nowhere.

    A new study describes a technique for improving sea state predictions. In their model, the team first use multiple radar returns to average out gaps in the current wave state data, then feed that interpolated data into a prediction algorithm that includes nonlinearities up to the third-order. The results, they found, gave far better predictions than current techniques, some of which had errors 3 times as high. (Image credit: R. Ding; research credit: J. Yao et al.; via APS News)

    Fediverse Reactions
  • Rip Currents and Hurricanes

    Rip Currents and Hurricanes

    When it comes to the beach, looks can be deceiving. That calm-looking water to the side of big crashing waves may actually be a rip current that carries water back out to the ocean. Rip currents are a result of conservation of mass; just as waves carry water to the shore, something has to carry that incoming water back out to the ocean. Depending on the local topography, that outflow could be below the water surface, creating an undertow, or along the surface, as a rip current.

    Even when far offshore, hurricanes can trigger unexpected and strong rip currents, largely because they create bigger waves that travel shoreward. Those waves can also change the depth and layout of the underwater shoreline, potentially exacerbating rip currents.

    For more on rip currents, including the latest guidance on how to escape one, check out this article. (Image credit: A. Marlowe; via SciAm)

    Fediverse Reactions
  • A Sandy Spine

    A Sandy Spine

    Where sea and sand meet, Gaia’s spine rises. Photographer Satheesh Nair captured this striking image in western Australia, where wind and wave action have dragged a dune into vertebrae-like cusps. Notice how the size and shape of the curves differs between the under- and above-water sections. Those differences reflect the differing forces that shape them — just water for one set, water and air for the other. (Image credit: S. Nair/IAPOTY; via Colossal)

    Fediverse Reactions
  • “Surfing on the Other Side”

    “Surfing on the Other Side”

    Surfers come in many forms — humans, robots, birds, and even honeybees. Most of the time, though, we see surfers above the water. In this award-winning photo, on the other hand, the surfing penguin shoots by beneath the water, riding beneath the wave’s crest. Keeping pace with the breaking wave should be no trouble for a penguin. They waddle awkwardly on land, but they have incredible speed in the water. Years ago, a penguin streaked past me in the water like a rocket to my paper airplane. (Image credit: L. Fitze/BPOTY)

  • Waves Break Up Floating Rafts

    Waves Break Up Floating Rafts

    Small particles can float on a liquid, held together as a raft through capillary action. But those rafts — like the tea skin below — break up when waves jostle them. In this study, researchers looked at how standing waves broke up a raft of graphite powder. Although the raft’s break-up resembles fields of sea ice breaking apart, the researchers found that different mechanisms were responsible. In their experiment, waves pushed and pulled horizontally at the raft, causing it to fracture. But that push-and-pull is negligible in sea ice, where sheets instead break from the up-and-down motion of waves vertically bending the ice. Nevertheless, the new insights are valuable for various biofilms and some ice floes. (Image and research credit: L. Saddier et al.; via APS Physics)

    The skin atop a cup of tea breaks up into polygons after stirring with a spoon.
    The skin atop a cup of tea breaks up into polygons after stirring with a spoon. Although the effect resembles sea ice breakup, the specific wave mechanism differs.
  • Breaking in Rogue Seas

    Breaking in Rogue Seas

    Many models for forecasting ocean waves simplify the physics by assuming that waves are essentially two-dimensional, like a long breaker heading toward shore. But in the open ocean, waves often come from more than one direction; crossing seas are a good example. When waves from different directions combine, a recent study shows, the resulting wave can grow far larger and steeper than expected. These monstrous rogue waves are especially dangerous for offshore infrastructure like oil rigs and wind turbines, which must be built to withstand rare but extreme waves. (Image credit: O. Мороз; research credit: M. McAllister et al.; via Gizmodo)