Earthquakes are coming to queensland.... underwater tremours causing unexpected swell.......bit of a long shot
Earthquakes are coming to queensland.... underwater tremours causing unexpected swell.......bit of a long shot
any fellas that surf will tell that in a set the 4th or 6th wave, can't remember exactly, are always bigger than the rest. maybe more pronounced in open water?
The waves/swells i refer to are actually occuring inside moreton bay between nth straddie and mainland which is actually enclosed waters more an estuary than an open bay. Nth Stradbroke encloses this area and blocks any swell or ocean type waves from entering this area eccept for further north (south east passage bar) between nth straddie and morton island. Wind swell and chop occur in this area but every so often up comes a large swell sometimes in a different direction than the swell occuring.
i was actualy not infering any tremor or quake activity rather that any smaller swell could possibly build rapidly when hitting shallow water as a tsunami does.Originally Posted by morty103
Earthquakes are coming to queensland
As others have already said - no such thing as a freak wave. On average most waves at a given time are around the same size - some a bit bigger and some a bit smaller.
It's the "above average" and "way way above average" waves that happen at the extreme ends of this sample spectrum that get the "freak label. Think of it in casino Money Wheel terms
The money symbols come up 99% of the time, some values are higher than others but the're all pretty similar.
Conrad can be the smallest wave - comes up very rarely and in wave terms we don't even notice it
Jupiters is the biggest wave - again comes up very rarely but because it's big, we really notice it.
You should always be expecting these"freaks" at any given time, and have a plan in place for when you come across one, or it comes across you. You should also remember that a wave that is bigger than average on the open ocean, can be MUCH bigger than average when you add in a bar, a seaway, a run out tide etc etc etc. This maybe why so many people run into trouble in these areas/conditions. Then it's easy to blame a "freak" wave that was out to get them. Probably also less a case of bad luck than bad planning.
What's the moral of my story?
Give yourself the biggest margin of safety/error you possibly can.
Then double it.
Then add 6.
Look after yourselves.
coming back from mud island 1 fine moonlite night dead flat heading to clontarf next minute we were airborne and bang hit the water again pulled straight up and looked all around us not a boat in sight and completely flat we reckon one of the navys subs had just gone through and we got the wake there was no other boat in sight no light nothing and it was a clear moon lite night
As others have already said - no such thing as a freak wave. On average most waves at a given time are around the same size - some a bit bigger and some a bit smaller.
It's the "above average" and "way way above average" waves that happen at the extreme ends of this sample spectrum that get the "freak label. Think of it in casino Money Wheel terms
The money symbols come up 99% of the time, some values are higher than others but the're all pretty similar.
Conrad can be the smallest wave - comes up very rarely and in wave terms we don't even notice it
Jupiters is the biggest wave - again comes up very rarely but because it's big, we really notice it.
You should always be expecting these"freaks" at any given time, and have a plan in place for when you come across one, or it comes across you. You should also remember that a wave that is bigger than average on the open ocean, can be MUCH bigger than average when you add in a bar, a seaway, a run out tide etc etc etc. This maybe why so many people run into trouble in these areas/conditions. Then it's easy to blame a "freak" wave that was out to get them. Probably also less a case of bad luck than bad planning.
What's the moral of my story?
Give yourself the biggest margin of safety/error you possibly can.
Then double it.
Then add 6.
Look after yourselves.
The waves that pop up out of no where sound very much like constructive-destructive inference waves. What happen is the the swell or waves come together and either cancel each other out or double up on top of each other. To me it would make more sense that this happens in the bay, especially near the centre of the bay or near an island such as Peel. Hence, you would have two incoming waves from different portions of the bay causing constructive interference waves.
This could also happen at sinking rock. No apparent incoming large waves, but the small waves could double or triple up and cover the rock. This would be totally different to oncoming sets.
Hi Dicer
If its the sinking rock in tassie you are talking about, they tell me its caused by a ground swell. As the appently calm water gradually rises from the off shore pressure it slowly builds on the outside of the reef. the inside slowly drops away and then the groundswell drops over the reef and shoots a big curly FREAK wave over the rock, when it does happen there is no time to move, all you can do is wedge yourself into the crevisis on the rock and hang on, the force of the wave will drive you into the crevis and then you need to hang on while the wave drops away. Only had it happen once and thats enough for me. there has never been a life lost here but every year someone gets washed off but as luck would have it the current drops you on a beach about 150m away fairly quick.
cheers
blaze
This was in the news a while ago. Doesn't apply to the bay but scary all the same [smiley=end.gif]
Freak Waves Are No Tall Tale
Massive waves up to 100 feet in height -- once thought to be extremely rare -- actually roam the oceans quite frequently and could threaten to overturn ships and oil rigs, a European Commission study has found.
The study, announced last week and conducted on radar images gathered by two European Space Agency satellites during a three-week period in 2001, revealed that no fewer than 10 of the so-called rogue waves rose from various oceans around the world in that time. Not too long ago, scientists had believed that such waves formed just once every 10,000 years, according to the space agency.
The findings could lead to the prevention of many wave-related accidents in the future, said Wolfgang Rosenthal, lead researcher for MaxWave, the European Commission-funded group responsible for the study.
"MaxWave formally concluded at the end of last year although two lines of work are carrying on from it," he said in a statement outlining the group's research. "One is to improve ship design by learning how ships are sunk, and the other is to examine more satellite data with a view to analyzing if forecasting is possible."
Preventing wave-related accidents is both a financial and safety concern for the maritime industry. Most large ships and oil rigs are designed to withstand waves up to 50 feet. However, in 1995, an instrument onboard the Draupner oil rig in the North Sea recorded an 85-foot wave.
In 2001, two cruise ships in the South Atlantic -- the Bremen and the Caledonian Star -- reported that their bridge windows were smashed by 100-foot rogue waves.
MaxWave researchers suspect that rogue waves also played a role in the sinking of some of the 200 large supertankers and container ships that have gone down in bad weather over the past two decades.
Unfortunately for those in harm's way, there is still much more research to be done before a solution can be proposed. For instance, no one yet seems to know how the waves are formed in the first place.
"We don't know what's going on out there," said Paul Liu, an oceanographer and rogue-wave researcher with the National Oceanic and Atmospheric Administration. "There are some theories, but I don't think those theories can ever translate into the real ocean environment."
One of those theories is that when two waves meet under the right conditions, they create one large wave. However, Liu discards that theory as being much too simple. "That's the easiest way to visualize it, but that's more or less linear theory," he said. "It can be done. But if that's the case, you should be able to see it all the time."
Indeed, while rogue waves have been found where currents meet, they have also appeared far away, leading researchers to believe that wind and other weather-related phenomena may also contribute to the waves' size.
A new project, dubbed WaveAtlas, is now attempting to shed light on the mystery by creating a catalog of waves and related accidents that can be examined for correlations. The project group is expected to publish its findings in early 2005.
Liu said he is encouraged by the research so far, but noted that he would also like to see more in situ measurements, like the one taken by the Draupner oil rig. Ships could also carry recording devices, he suggested.
"I think there are a lot of rogue waves out there," he said. "It's like if a tree falls in the forest and no one is around to hear it. What happens if a wave appears in the ocean and no one can record it?"
There's got to be some explanation for it happening inside Straddie, big container ships don't go that far south. Whenever I've experienced a "freak wave" I've been able to spot a 60ft Mustang Sports Cruiser that has just gone within 2 metres of me when there only 2km of water for him to overtake.
Haven't yet experienced an unexplained one, but I spend most of my time down at the Pin and never seen one there.
Would be interested to see where exactly these are happening to build a profile of "black spots"
Have surfed for 20 odd years and must say I don't believe it. Sure there are bigger waves in a set but if these so called 100' monsters were to hit land when and where does it happen? Like Charlie says it makes for a nice explanation for the guy that f***** up and got it wrong going over the bar. On a 3' swell day there sure can be a 6' wave in there but in my view never a wave more than twice the average swell size. The only occasion this happens in open ocean is when a swell is rising from a low pressure sysytem situated a long way out to sea. You might see a wave that is say 10' when everything else has been 3-4' all day but the periods between those waves will become shorter as the swell gradually increases. Not sure about the bay but it could be the bar or freighters, there is not scientific explanation for it that I could understand.
Well if you do a google search it would appear they definately do occur.
But I wouldn't call anything under 2 metres in Moreton bay a freak wave , regardless of how smmoth the rest of the ocean was.
I think Heath has a story about a set of three monsters on the Tweed Bar.
Heath?
Freak waves do exist - just look on your chart near hutchies and wide of moreton near deep tempest. It is clearly stated on the chart that they exist in that area - bright red text on my chart.
The cause for these is pretty much what DICER was saying - constructive - destructive waves. The definition of a freak wave is one that is double or more of the typical seas and swell that is being experienced in the area. They can come from the same direction as the typical sets, or sometimes can come from side on however side on is normally a product of converging currents / tides / wind.
The ones that come in the same direction usually are just 2 waves that got into sync with each other and stood up together as one wave temporarily for 50 or so feet of the waves travel, and then drops back into the general slop again.
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