Astrum Space - The Deep Ocean Has Its Own Weather System | Astrum Earth

Episode Date: October 14, 2026

The most extreme weather on Earth doesn’t happen in the sky… it happens deep in the ocean. From 200km underwater waves, to lethal blizzards, ocean blackouts, and the icy "finger of death" freezing everything in its path, the ocean’s depths are far more chaotic than we ever imagined. In this video, we’ll explore the science behind the most terrifying deep sea weather events on the planet.▀▀▀▀▀▀For 72 hours, 15% OFF all Hoverpens with code ASTRUMEARTH, or click the link https://noviumdesign.shop/AstrumEarth - Free shipping to most countries. Also on Amazon: https://noviumdesign.shop/WXwHyk▀▀▀▀▀▀A huge thanks to our Patreons who help make these videos possible. Sign-up here: ⁠https://bit.ly/4aiJZNF

Have you ever looked into the ocean and thought, I wonder what the weather's like down there? Well, truthfully, neither had I. And that got me thinking. Why hadn't I? When we think of extreme weather, we look up. We track hurricanes across the Atlantic, watch radar systems for supercells, and brace for blizzards during the winter. But what have I told you some of the most violent, massive and most complex weather systems on Earth, aren't in the sky at all. No, they're thousands of meters below the surface in the deep, dark abyss. Down here, invisible storms howl across the sea floor, giant whirlpools spin for years on end. Currents reverse without warning, sediments are whipped into temporary blizzards,

and massive underwater waves taller than skyscrapers surged through the darkness. The deep ocean has its own weather and for the first time we can see it. I'm James Stewart and you're watching Astrom Earth. Join me in this video as we plunge thousands of meters below the surface for the ultimate tour of Earth's most violent deep sea weather. We'll unpack how a 200 kilometre wave can form under the ocean. Discover why a marine blizzard 5 kilometers below is crucial to life on the surface and meet the icy fingers of death,

capable of freezing anything they touch. The forecast for this video is anything but predictable. The year is 1893, and Norwegian Arctic explorer Frit Tof Nansen and his three-masted schooner are stopped dead in Russia's kerosy. As if held by some mysterious force, he wrote in his expedition diaries. He was unable to move his ship. It simply would not budge, no matter what he tried. He called it dead water. So what was going on here? Well, it turns out he wasn't going mad and his ship really

was stuck. And it's thanks to a phenomenon that today we call internal waves, a wave within a wave, if you will. These are the largest waves produced in the world's oceans, with up to 10,000 times the amount of turbulence typically found in the open ocean. And the crazy part? Every single day, these waves, some as tall as the Empire's state building and up to 200 kilometers wide, form in the waters between Taiwan and the Philippines, rolling across the South China Sea. But from the surface, you would have no idea they were there. In fact, if you were bobbing around in the ocean having a lovely time on your boat,

the only clue to a monster wave passing right underneath you might be the faintest hint of a slick on the sea surface, a line of smooth water, usually preceded by a rough line of water that satellites see as enormous U-shaped ripples expanding outward, or that are detected by echo sounders hung off the back of boats. Echo sounders act like a giant ultrasound machine to scan the sea, floor, using reflected saul waves to paint a picture of the ocean's structure.

This is the only real-time way to see the internal waves, which is why they were largely unknown to science until 1909. So how does a wave this big hide from our prying eyes? I hear you ask. Well actually, creating waves that are visible at the surface isn't as easy as it sounds. There's a huge difference in density between water and air, and that means that pushing water up is hard. There's nothing to help support it against gravity pulling it back down. Under the water, however, that's not such a problem. Not all seawater is equal, and different

bodies of water vary in density thanks to slight differences in temperature, salinity and other ocean variables like pressure. But despite that, the differences are comparatively small. One mass of seawater may be only slightly denser than the water above it, which means considerably less energy is required to displace it vertically underwater than at the surface. The result is that the same basic wave physics can produce much larger movements underwater. Leslie Baer, a marine scientist from the Woods Hole Oceanographic Institution, was part of an expedition hunting for internal waves in 2014. when she spotted something unusual on the echo sound.

A mysterious and diffuse turquoise layer from the surface down to about four and a half metres, given the appearance of a bottle of unmixed salad dressing. She described it as sort of a turquoise oil sitting atop sapphire vinegar. The turquoise was warmer, less dense water sitting atop a sapphire layer of cooler, heavier water. And it's where these layers of. meet known as the interface that these quirky waves form. Broadly, scientists divide the ocean into three vertical layers. The first is the upper mixed layer, or the UML, which tends to be 20 to 40 metres thick

and is strongly mixed by wind shear, where wind moves the ocean's top layer of water faster or in a different direction than the deeper water beneath it, therefore mixing it all up. Waves breaking up the surface also play a part tier too. The UML is usually the warmest part of the ocean, because basically it's at the top where sunlight can hit it. At the sea floor, the bottom boundary layer, or BBL, is around 10 meters thick. Now, this layer gets mixed up by flow shear, changes in the speed of water as it gets dragged over the sea bed. Between the UML and BBL is, well, all the rest of the water in the ocean, which is relatively calm in comparison. but does have a temperature gradient called a thermocline,

where the water goes from colder at the bottom to warmer at the top. That thermocline creates a massive density difference between the top and the bottom of the layer, which completely separates the UML and the BBL. Energy, momentum mass, all stay in their own layers. Because of their density differences, these layers of the ocean behave like different fluids entirely. So when tides, currents,

and other large-scale effects of Earth's rotation and gravity drag water masses over some seafloor formations. They can create wave actions within the sea, kind of similar to what happens above in the atmosphere with weather systems. But internal waves do something else too, something very sneaky. Remember Nansen, our 19th century Norwegian explorer from earlier? Well, the dead water he described was exactly this.

The water below him was less salty because sea ice was melting into it, so it was sort of fighting against the saltier, denser water below. But that internal wave also stole the energy from his ship. I told you, sneaky, or maybe physics-y, because part of internal wave formation happens when energy disturbs the boundary between layers of water with different densities. Those layers may remain largely separate, but the boundary between them can be pushed up, down and begins to oscillate. In that sense, an internal wave is not so different from an ordinary

wave at the sea surface. Surface waves travel along the boundary between dense seawater and much lighter air, while internal waves travel along a boundary hidden within the ocean itself. At the surface, wind is often what creates the initial disturbance, pushing water upward before gravity pulls it back down again. But inside the ocean, the trigger can come from many other places. A ship, for example, can disturb a density boundary as it moves through the water, or tides can force whole layers back and forth. So when those layers encounter an underwater ridge or a mountain, they can be pushed up or down over the topography. It's a bit like being on a roller coaster. The car you're in follows the dip as it goes up and down, although I'll leave the roller coasters to you. I absolutely hate them, to be honest. Anyway, as Nansen tried to move his boat, ironically

some of the energy from the ship's propulsion system was actually siphoned off into internal waves, rather than being used to move the boat forward efficiently, although I do hope you eventually managed to get free. But one question still remains, where does all that energy actually go? Waves on the surface eventually break, whether that's on land or out to sea. But does an internal wave just keep going and going and going and going? Well, the truth is until 2015, we had no idea. For nearly seven years, a team from the Scripps Institution of Oceanography was tracking internal waves to answer this very question. In one place in particular, the South China Sea.

In the northern part near the Luzon Strait, the perfect ingredients exist to make this area a breeding ground for huge internal waves. There's a gradually shallowing topography from southwest to northwest, and the narrow waterways in the Eastern Philippines make this perfect. In the May issue of the journal Nature in 2015, they portrayed for the first time the entire life cycle of internal ways, from cradle to grave, and they found something profound. These monsters, as it turns out, actually help us. Speaking of things behaving strangely under forces we can't see,

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Enjoy your new pen and whilst you do that, let me get back to explaining how internal waves may actually help us. Let me explain here. So using a combination of data from the Luzon Strait and models to recreate the lifespan of these internal waves, They figured out that a large fraction of the waves' energy dissipates when the wave gets steep and breaks on the deep continental shelf in this region. In the same way, breakers break on a beach.

But here's the clever part, because part of that energy actually remains with waves reflecting from the coasts and bouncing back into the ocean in different directions. This process happens every single day and has huge effects on what's going on below the surface. As that energy spreads, it becomes one of the primary delivery mechanisms for the nutrients that make these coastal regions fertile fishing grounds, and could also be a key driver of the rich marine biodiversity found in places like the La Jolla Kelp Forest. Ultimately, these waves are what mixes heat throughout the ocean. I really like the way Jonathan Nash, the study's co-author phrased it.

He said, it's like stirring milk into your coffee. The internal waves are the ocean's spoon. So, yeah, although we rarely see them, they influence everything from marine ecosystems to the way heat is stored and moved through the global ocean. And all of that stuff has a huge impact on global climate and, of course, us. When I first started reading about internal waves, they blew my mind, honestly. But if you're sat there going, yeah, thanks James, they're very cool and everything.

But this isn't weather. Well, here's the tricky thing about deep sea weather, because if you do a quick Google search for it, you won't find an awful lot. Trust me, I looked. And there's a very good reason for that. It turns out deep sea weather isn't a sort of one-stop shot for scientists in the same way atmospheric weather is. Now, I'm not saying they're wrong to not include it, but I do think they're missing a trick,

and that's why I wanted to make this video. Not everything controlling the weather has to look like weather, especially not the weather that we're used to seeing every single day. In our atmosphere, invisible pressure gradients and waves can transform the conditions around us, and the deep ocean has its own hidden machinery. And it turns out one of its most powerful components is this wave that you could sail straight over without ever even knowing it was there, which I think is pretty awesome. Imagine living on that seabed, having a great day, then suddenly, bang, big antenna wave

comes along, that current accelerates, temperature drops, nutrient-riched, nutrient-rich water surges up slope, plankton moves with it, turbulence erupts as the wave begins to break, and a few hours later, the events passed. Now, to us, that's fluid dynamics, but to an animal living there, it's something much more familiar. It's a change in the weather. If internal waves are part of the machinery behind deep sea weather, then our next phenomenon might be the closest thing the ocean has to a travelling weather system. And they make internal waves look like ripples by comparison.

Enormous rotating masses of water constantly wander across our planet. At its simplest, an eddy is just a circular current, a body of water spinning away from or within a larger flow. But that, slightly underwhelming definition, highs their extraordinary scale. The ocean's major eddies can grow up to 500 kilometres, reach depths of 2,500 meters, persist for weeks or even months, and venture 4,500 kilometers before finally fading away. In fact, Noah's geophysical fluid dynamics laboratory

describes mesoscale eddies, typically less than 100 kilometres across, explicitly as the weather of the ocean. So, yeah, they've really earned their place in this video. Collectively, eddies across the globe account for more than 100, half of the kinetic energy associated with ocean circulation. Think of all those neat arrows you see on maps of ocean currents. Well, the eddies are the chaos wrapped around those arrows. And that chaos does an enormous amount of work. They transport heat, salts, carbon, nutrients, oxygen and organisms across enormous distances. Eddies matter. And the way they form, you'll be pleased to know,

is just as chaotic. Think about the jet stream in our atmosphere. It doesn't travel around the planet as one perfectly smooth ribbon of air. No, it bends and wriths, develops enormous meanders and sometimes pinches off rotating weather systems. Well, major ocean currents can do something surprisingly similar. Take the Gulf Stream, for instance.

Water within it can move rapidly beside much slower surrounding water, creating enormous differences in velocity and density across the current. Eventually, those gradients can become unstable. A meander grows, curls back on itself and can pinch off from the main current, leaving behind a rotating ring of water. Once formed, the rotation can persist because of the balance we've encountered elsewhere in this story. Differences in temperature and salinity create differences in water density and pressure. Gravity wants to flatten those differences out, but on a rotating Earth, moving water is deflected by the Coriolis effect.

This water isn't just sort of spiraling helplessly into some abyss, no, it orbits around the eddies' centre. Those cyclonic eddies often lift deeper density water upwards, bringing colder, nutrient-rich water towards the surface, whereas anti-cyclonic eddies often push those surfaces downward. The reality can become considerably more complicated once winds, eddy age and local ocean conditions are involved. But the crucial idea here is that an eddy doesn't merely move water sideways. It can rearrange the ocean vertically as well and that leads to some astounding results. The really strange thing is that an eddy is much like an internal wave actually, not obvious from above in the slightest. Satellites have revolutionized oceanography and because many mesoscale eddies can create,

tiny bumps or depressions in sea surface height that radar altimeters can detect, we can actually see them, sort of. But the surface is only a slice through a genuinely three-dimensional structure here. Some eddies extend far down into the water column, while others are concentrated almost completely beneath the surface. One particularly beautiful example is a Medi or Mediterranean eddy, as extremely salty Mediterranean water escapes through the straits of Gibraltar. and sinks into the Atlantic, it creates enormous eddies, hidden hundreds of metres beneath the sea surface.

These are essentially underwater weather systems with almost no obvious whirlpool directly above them, but some eddies go deeper still. And not even that, not every eddy begins near the surface at all. Now these are particularly mysterious because unlike the enormous swirling systems we contract from satellites, some deep ellies leave virtually no footprint at the sea surface at all. Which is why quite incredibly when scientists finally caught a glimpse of one of these in the South China Sea, they were pretty shocked. Between 2009 and 2012, researchers had moorings anchored near the Shishar Islands in the South China Sea, continuously recording currents and temperatures through the water column.

For most of the time, the deeper ocean water was relatively sedate. Below 1,000 metres, currents were moving at speeds of less than 0.02 meters per second, but in April 2012, something changed. Over the following weeks, currents at depth accelerated dramatically, reaching approximately 0.18 meters per second, around 9 times above normal. At the same time, temperature measurements reveal that surfaces of equal temperature or isotherms have been pushed downward by roughly 120 meters. Now that might sound like a bit of a strange thing to measure,

but it was actually one of the clues that revealed what was really happening here. Normally different temperatures occupy different depths in a stratified ocean. So if you then find a particular temperature 120 metres deeper than it ought to be, something has physically distorted the ocean's internal layers. And in this case, that something was a huge rotating, deep Eddie. And when I say deep, by the way, I mean genuinely deep. The energetic circulation was concentrated more than a kilometre below the surface, with little corresponding Eddie's signature above it. This was essentially a weather system hidden inside the ocean. But how do you make

a giant whirlpool a kilometre below the ocean without any sign of it on the surface? Well, the answer, quite beautifully, involves an underwater mountain. You see, the Shishar Islands sit above some rather complicated submarine topography, including large sea mounts rising from the deep sea floor. So when moving water encounters one of these obstacles, it doesn't just stop, it has to flow around it. Chen and his colleagues concluded that an upper ocean flow itself influenced by a subsurface cyclonic eddy. So basically, as that flow interacted with the mountain, it generated a wake in the water below, producing a rotating vortex. in the deep ocean.

The seaman was effectively acting like a gigantic vortex generator. With this research, they showed Ennis aren't just surface whirlpools somehow extending a long tentacle towards the bottom, but instead that the upper ocean can provide the initial disturbance. The shape of the seafloor can transform that energy and create an entirely new rotating system at depth. But there's also a very sinister side to them as well. A side that can potentially swallow ships.

This is where we should talk about whirlpools, because I can't keep saying giant ocean vortex and not do that. So, yes, there really are spectacular whirlpools in the world. Places like Norway's Salt-Schormann develop extremely powerful ones. Matt Damon's crew in Odysseus, you name it. But these are not quite the same phenomenon as a 100-kilometer-wide mesoscale eddy. An open ocean eddy is so enormous that its surface slope can be extremely subtle. A ship doesn't normally reach its edge and suddenly spiral dramatically towards the centre like something disappearing down a bath plug.

No, from the deck, you may not even realise you're inside one at all. Deep-sea eddies for things travelling underneath them are potentially more troublesome, however, precisely because they're so difficult to see coming. Those kinds of unexpected currents and density changes can complicate. underwater navigation and vehicle control. There's even a dramatic, although more cautiously source example of this. In 2014, Chinese submarine 371 reportedly began descending unexpectedly before its crew regained control, and some suspect an Eddie was the culprit. It was like a fast car suddenly running over a cliff, said the captain. I should just say that public evidence connecting that

specific accent to a measured Eddie is limited, so I'd treat it as an intriguing report rather than a scientifically proven case, but worth mentioning. The genuine danger then is not that a mesoscale Eddie opens a giant hole in the ocean and sucks everything into it. It's much subtler than that. Unlike our next weather system, by the way, which is anything but. Every so often that tranquil abyss is hit by a benthic storm. The name is wonderfully evocative, but basically scientists use it to describe episodes where currents close to the deep sea floor become strong enough to erode and re-suspend fine sediment. And when that happens, the view from the seabed can change dramatically. These storms were only really proven to exist

in the early 1980s, when Arthur Null and his team conducted their high-energy-ben-thic boundary-layer experiment, or Hebel, on the continental rise south of Nova Scotia. Instruments were placed roughly five kilometres beneath the ocean surface, where the understanding at the time was that background currents could be travelling at only a few centimetres per second. But during Benfic storms, those currents accelerated to around 20 centimetres. per second or more, while concentrations of suspended particles increased by orders of magnitude, persisting for days on end. The result was enormous clouds of sediment hovering above the seabed, known as benthic nephaloid layers. Which begs the question, doesn't it? What on earth could create a storm

five kilometers underwater? Well, the answer it turns out begins thousands of meters above. Researchers have known for decades that particularly energetic benthic storms in the western North Atlantic often occur between one of the most powerful currents on Earth, the Gulf Stream. This near-surface current doesn't just flow smoothly across the Atlantic as these wonderful images make it appear. No, instead it rives, develops huge meanders and sheds energetic ellies as it goes along. You know what? It's almost as if instability near the ocean's surface was somehow transmitting enough energy through kilometers of water to disturb the abyss below. There's no way, right?

Well, that's exactly what Saw Hyur and Sean Chen and his colleagues tried to work out in 2024. Using an ocean circulation model to simulate the instability of a surface current like the Gulf Stream, their hunch was confirmed. They discovered that when a powerful surface intensified jet becomes unstable and begins producing eddies, energy can be transferred downward into the deep ocean. Near the bottom, as the courage strengthen, the vertical shear increases and turbulence develops, creating conditions capable of lifting sediment from the sea floor. And in 2026, the picture became even more dramatic. Using a high-resolution model of the Western North Atlantic,

Chen and his colleagues concluded that an upper ocean flow, itself influenced by a surface cyclonic eddy, was steered across the sea mount. These cyclones are massive, I'm talking 100 to 200 kilometres in size, rotating anticlockwise in the northern hemisphere and forming near meanders of strong currents like, yep, you guessed it, the Gulf Stream.

The sea floor, in other words, is not just a sort of passive graveyard beneath the ocean. It's part of an active shifting system, and when that energy reaches the bottom, even a landscape 5 kilometres beneath the waves, can suddenly experience something remarkably like weather. But not every dramatic moment in the ocean is driven by turbulence or powerful currents, but sometimes just one degree can make all the difference. What's cooler than being cool? Brine call. I don't imagine you have immediate plans to go for a dip in the Arctic or Antarctic,

but if you ever do, keep an eye out for the icy finger of death, otherwise known as the brinacle. Capable of freezing anything it touches, brinacals truly are one of nature's greatest oddities. They look like descending tubes projected downward from floating sea ice on the surface of the ocean. a bit like an icicle hanging off your house. Except a brinicals length can be measured in meters instead of centimetres.

And instead of rainwater, it's formed from a super salty saline water solution called brine. When seawater along the ocean surface freezes to form ice, it chucks out a high concentration of salt because only pure water molecules fit into the rigid crystal structure of ice. All that extra salt then needs somewhere to go. it enters cracks and fractures within that ice. Eventually, though, this ice cracks and the salt leaks out into the nearby seawater and increases salinity, leaving behind pockets of extremely cool, concentrated brine. Now, that brine is much denser than the seawater around it, so gravity pulls it downward,

and as it sinks, something otherworldly happens. The freezing brine becomes wrapped inside a descending tube of ice, a bare. brinacle. In fact, these things are so wonderfully creepy that in 2011, a British tabloid ran the headline, the underwater icicle of death. Catchy. But actually, for once, they were sort of right. I mean, to you and I, touching one would be mildly inconvenient, but there are reports of bottom dwelling creatures running into them and meeting their icy demise. So if you are a sea urchin, approach with caution. Now I know, at first, this might see. completely disconnected from all the deep sea weather stuff we've talked about before.

And that's because, firstly, I really wanted to squeeze this into the video because they are awesome, but also they do reveal the same fundamental truth about the ocean. Seemingly small changes in the physical properties of seawater can set enormous movements in motion. With benthic storms, energy and momentum reach the seabird and resuspends sediment. With brinicles, differences in temperature and salinity change the density of sea. of seawater enough for gravity to send it plunging downward. And although a single brinical may descend only a few meters, the physics behind it scales it up spectacularly.

Around Antarctica, the same production of cold, salty, dense water helps create water masses that sink off the continental shelf and spread into the deepest parts of the global ocean. So yeah, we've gone from a storm raging across the abyssal floor to something powered not by, violent currents, but by something much simpler. Cold, salt and gravity. Within all of this, much like our own atmospheric weather really, there is one key driver, one energy source that powers many of the currents and large-scale movements in our ocean. And with that, we come to what's

arguably the most sinister deep-sea weather phenomenon of all, one that isn't really about moving water as such. But what happens when something disobeyser? Imagine living somewhere where your entire ecosystem depends entirely upon sunlight, and then, in the middle of the day, someone turns the lights off. If you thought dark overcast winter months were bad, well, imagine that. Not for an hour, not even for a day, but for weeks. For the first time in January 26, scientists introduce a new terrifying concept, marine dark waves, intense episodes of underwater darkness that can last from days to months,

and push marine ecosystems into acute stress. Francois Thorold and an international team of researchers published the first formal framework for identifying and comparing marine dark waves. And they did this just a few months ago, and honestly, the news is harrowing. Now, not only was there no name for marine dark waves, there was also no consistent way to even measure these extreme events up until now. Speaking as part of an interview with the conversation in 2006, Thorough describes dark waves as occurring when underwater light falls below a depth-specific threshold for a minimum duration,

relative to what is normally expected at that location. It's this differentiation that helped them to identify when conditions shift from merely dim to unusually dark. To develop this, Thorell and his colleagues assembled some unusually long records of underwater light, and we're talking 16 years worth of measurements from Santa Barbara in California, 10 years of observations at two depths in New Zealand's Firth of Thames, and 21 years of satellite-derived estimates of seabed illumination around New Zealand's East Cape. What they found weren't merely slightly gloomy periods. they found total blackouts.

At the Santa Barbara site, for example, one major dark wave which began in June 2021, persisted for 30 days and produced an overall light reduction of roughly 80% relative to normal conditions. Across the study as a whole, the most extreme events approached 100% loss of expected light at their peaks.

For an organism dependent on photosynthesis, that's not simply bad weather. That's a crisis. So yeah, I'm sure you're wondering, how do you make an ocean go dark? Sunlight entering the ocean is gradually absorbed and scattered as it travels downward. Even perfectly clear seawater removes light with depth, which is why eventually we reach the permanently dark or aphotic ocean. But add material to that water and the rate at which light disappears can change dramatically. It's a bit like shining a torch through a glass of clean water. Most of the beam passes through, but if you start in some fine mud, then some of those photons are absorbed, while others are scattered away from their original path.

Well, much the same thing can happen in coastal seas. A storm can churn sediment from the bottom into suspension. Heavy rainfall can wash enormous quantities of soil and organic matter from rivers into the sea. Floods can produce vast brown plumes of sediment extending offshore. Phytoplankton blooms can fill the water with light-absorbing cells, and actually there's a rather peculiar phenomenon here too that we've already talked about. Benthic storms can also help create darkness. Those enormous clouds of sediment we saw being lifted from the seabed don't merely transport particles. Suspended sediment also scatters and absorbs light.

This means that in shallow enough environments, energetic waves and currents that stir the bottom can contribute to sudden reductions in seabed illumination. Marine dark waves are perhaps the clearest demonstration yet that we can borrow the logic of atmospheric weather without pretending the ocean behaves exactly like the atmosphere. Because weather is ultimately about change, and the ocean, even in places that appeared timeless, cold and still, is changing all the time.

So perhaps the biggest surprise is that the deep ocean was never the same. silent, motionless world we once imagined. Internal waves carry energy through invisible layers. Benfic storms tear, settle material back from the seabed, and even light itself can suddenly vanish from places that depend upon it. None of these phenomena are weather in quite the way we experience rain, wind or thunderstorms, but maybe that's the point. Weather is really the story of an environment changing around you. And beneath the waves, those changes can be enormous. The ocean may look calm from above, but underneath that surface is a world of hidden storms, giant waves, blizzard shifting currents and blackouts, all moving energy, nutrients, carbon and

life around our planet. So next time you look out across a perfectly still ocean, perhaps don't ask what the weather is like above. Ask what the weather is. others like Underneath.