GypsyScy Posted November 8, 2009 Report Share Posted November 8, 2009 Did anybody else notice anything strange with the sea yesterday afternoon? Edit:Okay much to my embarasment my previous facts were not completely straight My father in law noticed a swell of water rising and come in from the west,he saw a huge swell for rise for about 3 minutes, looking directly west, mid channel, coming in between Hildasaay and the Cheynies off Scalloway. We checked today online to see if there had been any seismic activity of any kind in the north atlantic but nothing was registered anyway. Anybody have any idea's / theories Quote Link to comment Share on other sites More sharing options...
Njugle Posted November 8, 2009 Report Share Posted November 8, 2009 Swells of the west side were quite high yesterday, still quite high today. Depends where he saw it but it may well be a remnant of a proverbial 'hundred year wave', a phenomenon that has more recently been proven to be a fairly common deep ocean occurrence, it's just that usually there is no one around to see them - satellites now have the ability to tack such things. A 'hundred year wave' is a statistical/physical event created when a number of large swells run together to create one 'super-wave' much bigger than those around it. That's one suggestion. If a really big swell made it to the coast on the west side though, plenty of places would be affected by it. Any more info? Also: Swells off the west side were running at about 12ft yesterday, while on the east side, offshore, there were swells running 25-30ft That's notable. Quote Link to comment Share on other sites More sharing options...
crofter Posted November 8, 2009 Report Share Posted November 8, 2009 Also: Swells off the west side were running at about 12ft yesterday, while on the east side, offshore, there were swells running 25-30ft That's notable. Heard that the pier in baltasound has been damaged. The guy who told me said he has never seen swell running so far up the voe in his life. Quote Link to comment Share on other sites More sharing options...
Sheltie7 Posted November 9, 2009 Report Share Posted November 9, 2009 There was a big low to the west of Shetland now moving south, that could have something do with it. keenz. Gret muckle stoops o swell mid Atlantic eenoo, alot more than forecasted. Surely going to get waar... it's hard to be a sailor man. Quote Link to comment Share on other sites More sharing options...
nautim Posted November 9, 2009 Report Share Posted November 9, 2009 Did anybody else notice anything strange with the sea yesterday afternoon? My Father in Law saw a huge swell of water roll in on the west side off Scalloway and says he never saw anything like it before in his 73 years. He watched one great wave swell in for over half an hour and then that was it! When I came around the top of the Scord at the back of 4 I noticed that there was a lot of white water around the isles - like there was a huge sea breaking. I was tempted to go to Burra to watch the sea, but thought I'd better go home and sort the tea instead... As far as size goes - I'm no use at estimating wave heights out among the isles, but I drive around that corner most days and the surf caught my eye as being significantly rough compared to normal. I wish I had taken the photo I thought about taking now... Quote Link to comment Share on other sites More sharing options...
GypsyScy Posted November 9, 2009 Author Report Share Posted November 9, 2009 He did mention the Hundred Year Wave, he said it was by pure chance he saw it, A few minutes either side he would have missed it. Quote Link to comment Share on other sites More sharing options...
sjeunson Posted November 9, 2009 Report Share Posted November 9, 2009 A 'hundred year wave' is a statistical/physical event created when a number of large swells run together to create one 'super-wave' much bigger than those around it. Are you describing a freak wave not the 100yr? Standard wave theory doesn't take into account these waves which take the energy from those around it. It's some chaos type theory that allows the prediction of these waves I think. The freak waves can appear more regularily as they occur due to the different mechanism in which they form. Little difference in the end result though as either way it's a bloody big wave. Quote Link to comment Share on other sites More sharing options...
EM Posted November 9, 2009 Report Share Posted November 9, 2009 Standard wave theory doesn't take into account these waves which take the energy from those around it.Eh? What Njugle explained is, as far as I'm aware, the standard theory relating to the matter. I see nothing wrong with what he said, it is all a matter of wave superposition and probability distributions. Your comments are therefore somewhat intriguing. Could you please explain further? Quote Link to comment Share on other sites More sharing options...
sjeunson Posted November 9, 2009 Report Share Posted November 9, 2009 It could be he's taking about superposition but it sounds a bit to me that he may be talking about this chaos theory model. Was on the Discovery Channel while I was at Uni so they made us watch it as additional info. Basically the freak wave is formed not through superposition etc but by "sucking" (programs word not mine) energy from the waves around it. Hence a wave much larger than the waves around it could form relatively commonly. Therefore they had the view that most of the 100yr wave events found weren't actually the statistical 100yr wave we describe through standard theory but these waves taking energy from those around them to grow into the mosters described. Njugle wasn't wrong, just I was wondering which theory he was talking about. Quote Link to comment Share on other sites More sharing options...
EM Posted November 9, 2009 Report Share Posted November 9, 2009 Was on the Discovery Channel while I was at Uni so they made us watch it as additional info.Was it this BBC programme:http://www.youtube.com/watch?v=99mPmdh_wDYI've not watched it yet, but will do so to see what they are arguing about. I'm very interested in the topic for both professional and personal reasons. I experienced falling off such a wave once, and once was enough. Horrific. Quote Link to comment Share on other sites More sharing options...
sjeunson Posted November 9, 2009 Report Share Posted November 9, 2009 It wasn't a BBC documentary but several were made around the same time so it could be the same work it covers. It is a really interesting subject and I wish I'd done some more work on it for uni projects now I look back. Quote Link to comment Share on other sites More sharing options...
Ghostrider Posted November 9, 2009 Report Share Posted November 9, 2009 Obviously a higher wave contains more energy, and has been "pushed up" (for want of a better better) by that energy. How do you explain additional to average energy distributed the other way in waves though, horizontally. To put some bones on it, a bit over 20 years ago there was a very high swell running on the west side at the Ness, despite it being a near calm, the highest swell I've ever seen. The normal swell that I was watching from a vantage point was when the nearest to shore wave started to break on the beach, crest number four was starting to form equal to the tip of a headland. Being near calm the noise of the sea was the loudest around, and what first attracted my attention was a sudden silence, caused by the fact the last wave had run off, and the next one was missing, its crest was still a bit short of starting to break when I looked up. First odd thing about it was, it never broke, it ran right up the beach, smack in to the sand banking at the back. When it was at the point previous waves had broken, only wave number three was forming at the tip of the headland, so that was three taking up the space normally occupied by five. While the crests of these three waves may have been marginally higher and the troughs marginally deeper, they weren't of any significant amount.What was obviously very different was the widths of the troughs, there were significant areas of flat water in them, whereas the previous swells were normal, starting to rise towards the crest of the next wave as soon as they'd reached the lowest point behind the previous. As these weren't apprecably higher waves, logic would dictate that they should have broken at around the same place on the beach as their predecessors, the fact that they didn't and ran right on unbroken until they hit soild land, then took disproportionately longer to run off afterwards, would seem to suggest that the flat water following the crest somehow contained energy too that took time to dissapate. Quote Link to comment Share on other sites More sharing options...
sjeunson Posted November 9, 2009 Report Share Posted November 9, 2009 The energy in a wave is proportional to H^2. The fact that the waves had a longer wavelength is what caused them not to break. Think a wave breaks at a steepness of wavelength/7 roughly. Approaching the shore will cause the wavelength to shorten but if it's sufficiently long in the first place it won't break. Energy in a wave is transmitted at half the speed of the wave. Longer wavelengths mean the energy is transmited faster but it doesn't mean more energy. Hope that helps, memory is a bit sketchy to say the least. Quote Link to comment Share on other sites More sharing options...
phil Posted November 9, 2009 Report Share Posted November 9, 2009 A number of years ago, I was sitting on the rocks near my home on Bellingham Bay, in Washington. It was a warm, sunny, autumn afternoon, glassy calm seas and only a few boats on the water. Growing up in Shetland, I am very conscious of the sea and staying out of it's reach. I suddenly noticed 3 large waves heading for me, out of nowhere; - this is in Puget Sound, an enclosed bay, protected from the Pacific Ocean by the San Juan Island chain and Vancouver Island. The first wave, probably 4 feet high, washed completely over me, I had jumped off the rock and up the bank by the time the other two hit. Again, the Bay was calm, no boat wakes or other waves and all the waves originated from the shallow, enclosed North side of the bay. I was really quite shocked that I had been caught unaware by the water and couldn't really figure out what or how this happened. That night when I watched the news I saw the explanation. An Earthquake in Alaska which was felt as far South as Seattle. /http://community.seattletimes.nwsource.com/archive/?date=20021104&slug=quake04m One of my friends lived about 90 miles from the epicentre of this quake and was on the roof of his log home when it hit. He said he could see 3 large waves, around 3 feet high, running through the ground toward his house. The Earth, surrounding forest and everything else around it rose 3 feet as these waves passed. His main concern was his log home would unravel and collapse with him on the roof. Quote Link to comment Share on other sites More sharing options...
jeemypeat Posted November 12, 2009 Report Share Posted November 12, 2009 I stay somewhere that i have a clear view of the sea.From the kitchen window i can see nothing but the north atlantic (I stay at bannaminn)Needs to be said last week was terrible for swell, waves coming right over the banks which are around 20-30ft in height. Quote Link to comment Share on other sites More sharing options...
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