Real-time Earth and Moon phase

Wednesday, July 30, 2014

The new freaque waves article in NewScientist magazine

The latest NewScientist (Issue 2979) carried this online article by Stephen Ornes entitled "Rogue waves: The real monsters of the deep" just caught my eye. What I was surprised to see was this:

Seven giants
In 2007, Paul Liu at the US National Oceanic and Atmospheric Administration compiled a catalogue of more than 50 historical incidents probably associated with rogue waves. Here are some of the most significant . . .


Hmm . . .  I know that my Geofizika article has been reasonably well referenced, but this NewScientist citing is still a surprise to me.  Here's a discussion in a paragraph in the early part of the article:
Science has been slow to catch up with rogue waves. There is not even any universally accepted definition. One with wide currency is that a rogue is at least double the significant wave height, itself defined as the average height of the tallest third of waves in any given region. What this amounts to is a little dependent on context: on a calm sea with significant waves 10 centimetres tall, a wave of 20 centimetres might be deemed a rogue.
The lament about the lack of "universally accepted" definition is fine. But the dismissing of possible of a 20 cm high freaque waves is unnecessary.  Freaque waves may be able to reach tens of meters high, but its existence is not necessarily measured by its sice alone. An important characteristics of freaque waves  the definition can not be delineated is the unexpectedness of the occurrence of the wave. Even a wave of 20 cm tall, if it occurs unexpectedly, it will be a freaque wave nevertheless!

Over all this is the best general article on freaque waves written by a science writer I have ever read.  He must have done extensive researches on the topic of freaque waves.  I don't know if he had actually talked to the key players he cited in his article, but his choice of players and representing their works all admirably.

For this article I signed up for a short term subscription to NewScientist -- the only way to allow me the access the article in whole right now, it's worth it!




Sunday, July 27, 2014

Rescue below the Carrick-a-Rede Rope Bridge

Independent, Irish has this story happened on July 6 written by Michelle Smyth published on July 7:


Kayakers had to be rescued from below the Carrick-a-Rede Rope Bridge on the Co Antrim coast after a freak wave struck their vessels at the weekend. 
One of the rescued men, who wished to remain anonymous, said he was out kayaking with three of his friends near the bridge on Saturday when two of the men were knocked into the water and pushed towards rocks by a huge wave. "We are all fairly experienced kayakers and we would be out in the water a lot," said the kayaker, from Ballymena. 
"It was a shock this happened. I would like to thank the Coastguard and RNLI for their speedy response. They carried out a challenging rescue with the utmost professionalism." 
A vigilant National Trust employee raised the alarm and the Ballycastle and Coleraine Coastguard rushed to the scene, as well as Portrush Lifeboat. The two men, who had sought safety on rocks, were winched to safety by two rescue technicians and treated for minor injuries. 
- See more at: http://www.independent.ie/world-news/europe/rescue-drama-after-kayakers-hit-by-freak-wave-30411132.html#sthash.sduZNbw5.dpuf



Here is one of the published pictures showing the Coast Guard rescue in action underneath the famous land mark rope bridge.  

Happened at St John’s Point, Co Donegal, Ireland

Independent.Ie carried this news headline today: "Presbyterian minister drowns after being struck by freak wave" :

Rev Dr Stewart Jones, who was minister of Donemana Presbyterian Church in Strabane Co Tyrone,  got into difficulty shortly after he was struck by a freak wave during a dive at St John’s Point in Co Donegal on Saturday evening at 4.30pm.The two divers got into difficulties not far from the shore at St John’s Point, Co DonegalThe Coastguard helicopter was dspatched to scene after the alarm was raised yesterday evening around 4.30pmCPR was performed on the man on the beach.The victim, aged in his 50s and believed to be from Strabane in Co Tyrone, was airlifted to Sligo Hospital during a rescue operation on Saturday.Ian Scott, from Malin Head Coastguard, said cardiopulmonary resuscitation (CPR) was carried out.
"Sadly, despite administering CPR, from when the diver was recovered until his arrival at hospital, the man died."

So freaque caused a tragedy in Ireland today. The victim was A Presbyterian Minister and a experience diver. We don't know how and why. It just happened! The article can found in:  

Friday, July 18, 2014

Just ferret out: Two cases of freaque wave encounters in 1942 and 1977.

On Google search, with the help of using key words of  "Google news freaque waves" I came across this two pieces of old news paper gem news on freaque waves:

Freak Wave Drowns Seven in Lake Erie, from May 31, 1942's Pittsburgh Press;
and
Five Die After Trawler is Hit By Freak Wave, from The Glasgow Herald, Dec. 6, 1977.

I was particularly interested in an eyewitness account in the 1942 Lake Erie case:
     One fisherman described the waveas an enormous black wall that blotted out everything and rushed in with a deep, rolling rumble. 
     The only warning he said, was a shrieking noise like a siren which proceeded the wave.
which was copied from the hardly legible original newspaper:


Whether or not freaque waves make noise is still unsettled. Obviously there are freaque waves that don't make noises, but some did. This case in Lake Erie in 1942 was one of them -- a shrieking siren like sound described by an eyewitness would dispel any possible room for doubt!

Some other rather contrasting notes about these two cases: both reports used the term "freak wave" in the headline, both cases were tragic that involved unfortunate multiple life loses, while the Lake Erie case may have influenced by weather condition, i.e. sudden shift in wind, the Glasgow Herald report indicated the weather was "quite reasonable".

These two cases, 35 years apart, happened long before freaque waves ever become sensationally infatuated by the modern media types. One might even gather useful informations on freaque wave happenings from these old news reports that still valued and retains journalistic integrity. 


Saturday, July 05, 2014

A case in Fleurieu on 06/27/2014

I am not sure how many people are familiar with Fleurieu Peninsula, I am certainly not one of them, I have to Google through Wikipedia to learn that they are located in South Australia. In the Sunday, July 6, 2014, Victor Harbor Times, there's this article: "Fleurieu lifesaver warns people off rocks" with the following pictures:

 
 
REGION - A local surf lifesaver has warned that coastal rocks are "no place for bravado", after two men narrowly avoided being swept off rocks in Port Elliot last week.
Safety along local beaches has been swept back into the spotlight after the pair were photographed scrambling for secure footing after being knocked over by a rogue wave on the rocks at Knights Beach on Friday, June 27.
Goolwa's Mick Windibank witnessed the incident, and took photos of what he said were two young men on the rocks.
"This is why people are getting in trouble at our beaches; ignoring signage and not respecting the ocean in general," he said.
"Lucky boys I reckon."
Port Elliot Surf Lifesaving Club (PESLC) secretary Marty Smee said the rocks from Port Elliot to Knights Beach are dangerous places to be.
According to Mr Smee, millions of years of weathering has worn them smooth and slippery when wet, while algae growing on them further reduces grip.
"The waves are also unpredictable and come in fast," he said.
"You find it hard to outrun waves; especially on rounded, smooth rocks."
Mr Smee said there have been deaths in the area, although decades ago, and recalled at least two incidents in the last few years when PESLC members were required to save people swept off rocks in Green Bay, between Horseshoe Bay and Knights Beach.
"One of those was life and death, and skilful work on behalf of an IRB (inflatable rescue boat)?crew saved a young man," he said.
"Other people have received severe abrasions."
These are local informations, thanks to the bystander who took the pictures that makes the case more than just a heresy and they certainly should be made known so other similar areas around the world can learn to prevent future happenings. This rocky shore freaque wave case on Friday, June 27, 2014 is duly recorded as a freaque wave happening thanks to this article.  How many similar happenings got lost in the information world because no one's doing the recording.  At any rate we are happy that this one got recorded and most happy of all is that everyone's safe and sound just ends up a good lesson. Deo Gratias!

Thursday, July 03, 2014

Beware the warning signs and comply!

Here's a news item in Taipei Times I just read which a civil liberty minded people may find it's objectionable. but siding on the safety and saving lives, one can understand why the local officials in Taiwan would choose to do this:
In view of repeated incidents involving swimmers who ignored warning signs erected in the Kenting National Park of adverse sea conditions, park authorities said they have decided to slap fines of NT$3,000 on violators, effective yesterday.
Kenting’s South Bay (南灣) is a popular spot among swimmers, but three people drowned there last year because they ignored red warning flags, park officials said.
Kenting National Park Headquarters wrote “swimming prohibited” on its warning flags, but several students from Feng Chia University in Greater Taichung also ignored these warnings, resulting in the death of two.
“Now anyone who ignores the warning signs and goes swimming will be fined NT$3,000 for violation of the National Park Act (國家公園法),” the park headquarters said.
It said that if the waves are 1m high, it will set warning red flags to ban swimming, adding that if the waves are 1.5m high, it will ban diving.
Jetskis and other water activities will be prohibited if the waves are 2m high, the agency said.
In case of typhoons, the beach area will be cordoned off altogether, the park authorities added.
They said that in the past, they could only disperse violators and said that the fines might provide more of a deterrent.
On the first day of the new rule yesterday, it was a beautiful, sunny day in Kenting and there were many swimmers, but no warning signs on the beach.
So the moral of the matter is to beware the warning signs and be prepared to obey or risking on paying some large fines (NT3000 is equivalent US $100).  It will be difficult to fault the local officials' effort in trying to prevent damaging injuries and casualties.  We can certainly not excuse the college students who ignored the warning signs and ended up lost two companions. Is there better ways than large fines? There must be. But human nature as it is, we are still carrying our own life in our own hands.  Safety first, by all means, be mindful when there's warning signs!

Making Waves: the science of summer!


I just come across this interesting article entitled "The Science of Summer: Making Waves" that was published a week ago, June 25, 2014, in the University Press of FAU (Florida Atlantic U.) written by Luke Otfinowski.
The arrival of summer, for most, means a lot more time at the beach. Whatever your water activity, be it snorkeling, surfing, kiteboarding, paddle boarding or simply trying to enjoy a swim without getting your hair wet, waves are going to be there whether you want them to or not. It’s interesting thinking about where a wave starts, what determines its size, and if a butterfly beating its wings across the ocean means a tsunami is heading our way. The mechanisms for the formation and behavior of ocean waves are actually pretty simple and they might also help us figure out the meaning behind those “make waves” banners and signs we pass so often on campus. So, put on your floaties because here comes the break on waves!
When the sun heats the air on the uneven surface of the earth, certain portions heat up more quickly, causing that air to rise. This allows for cooler air to swoop in, fill the space, and create a lovely, cool breeze that is always welcome in South Florida. When this happens over the water, that cold air may brush against the surface of the water, creating a ripple. If the air continues blowing that ripple along, it will grow into a small wave and potentially keep getting bigger.
There are two main factors for a wave being formed and getting larger: the speed of the wind across the surface of the water and the distance of water over which the wind has blown, also called the fetch. The faster the wind is travelling and the further it travels pushing against the wave, the bigger it will be. Though most ocean waves are wind generated, there can be exceptions.
Dr. Brooks, a marine biologist at FAU, points to an event that occurred at Daytona Beach in 1992. Beachgoers were surprised by a rogue 18-foot wave that came out of nowhere and swept cars parked on shore, along with their drivers, into the water.
“It was most likely triggered by an underwater landslide or other seismic event. It was an otherwise calm day,” says Brooks.
 These and other major wave types can appear suddenly due to shifts of the ocean floor, such as earthquake movements or underwater volcanoes.
Waves are mostly just kinetic energy. The movement of wind transfers energy into the water and the waves move that energy. It is not the water that is being moved, but energy. The kinetic energy moves through the water in a circular motion, not a forward motion, like round cylinders moving a strap of a conveyor belt. This is why a buoy out on the ocean measures wave size by rising up and down in a bobbing motion as opposed to getting caught in a wave and moving across the water.
Another way to imagine this is to make a mark in the middle of a jump rope and swing the rope up and down, causing kinetic energy to move in a wave-like pattern away from you towards the other end. You would see that the marked portion of the rope did not actually move.
These waves of kinetic energy will travel thousands of miles until they begin to hit obstacles near the coast. Once the waves come in contact with obstacles, like offshore continental shelves, the friction will gradually slow the wave, making it lose part of its intensity. By the time the waves reach the coast, the swell has lost much of its previous energy and intensity. It would be much more powerful if it didn’t come into contact with so many obstacles on its journey.
Once the wave hits a sand bank, a reef or shallow waters, the wave slows down further, causing the wavelength to shorten, the crest of the wave to grow, and the height of the wave to rise. As the bottom slows, the top of the wave keeps moving and finally breaks, giving us the image of a classic white edged curve just asking to be conquered by a surfer.
So the next time you are walking around campus and pass under a banner telling you to “make waves,” you could think of it as a message encouraging you to be a kinetic force — a force that may start out as just ripples in a vast ocean, but with persistence can grow; a force that keeps moving forward, crossing new lands, passing obstacles and, though they may slow you down, not letting anything stop you until you make it to your goal.
When you think of it like that, it’s a pretty good message to live by.
 I thought it's a timely and useful article to read, even provided info on a freaque wave event unknown to us outsiders that was "occurred at Daytona Beach" in 1992. For which beachgoers "were surprised by a rogue 18-foot wave that came out of nowhere and swept cars parked on shore, along with their drivers, into the water."  And I thought the title of the article is a rather refreshing one to attractive attention. Really what else can be regarded as the science of summer?




Thursday, June 05, 2014

Freaque wave an amazing ocean fact?

The ABC Science of Australia just published an fairly interesting article online entitled: "10 facts about our amazing oceans". Of particular interest to me, of course, is its fact #6: Rogue waves really do exist.  Here's what they have to say:
For centuries maritime folklore has had tales of gigantic waves that would appear without warning in mid-ocean and sink ships, even in good weather. These rogue waves are not necessarily the biggest waves ever found at sea, but isolated waves way bigger than what any crew might expect in a given sea state. 
By definition, rogue waves are ones whose height is more than twice that of the prevailing conditions. 
The largest scientifically measured rogue waves were encountered in February 2000, by the British oceanographic research vessel, the RRS Discovery. West of Scotland it recorded individual waves of up to 29.1 metres, almost the height of a 10 storey building. 
The causes of these waves are not completely understood, however they seem to happen more often when a strong ocean current runs counter to the direction of the waves.

Basically all routine informations, nothing new there.  My initial reaction was the article is probably an article for the summer doldrum, but it's not summer right now in Australia.  Is this really an amazing fact? I guess it depends on what do you consider as amazing. Anyway, it's still an interesting, and educational article for recommended reading list.


Saturday, May 31, 2014

Freaque waves as icebreaker

In the midst of hot summer in North America, it's not timely to think of ice and icebreakers, but here's an interesting science article in www.stuff.co.nz entitle "Freak waves prove to be ultimate icebreaker" by Sarah-Jane O'Connor along with a video of helicopter deploying a buoy onto the Anarctic ice,  that just brings some cool summer thoughts to us:

''Freak waves'' observed by early Antarctic explorers break up sea ice hundreds of kilometres from the open water, New Zealand researchers have found. 
Scientists from the National Institute of Water and Atmospheric Research (Niwa) found that waves bigger than 3 metres break ice much further away from the sea-ice edge than previously thought. 
Niwa oceanographer Dr Mike Williams said the study, published in Nature today, provided vital information that had been missing from models of sea ice and its effect on climate.
‘‘When these experiments were last carried out in the 1970s and 80s, people needed to be sitting on the sea ice to take measurements and that meant they couldn’t be out there when the big waves came through,’’ Williams said. 
The Niwa team developed wave buoys, so they ‘‘were able to put those out on the ice and leave them out during big storms’’, he said
What was interesting to note is this:

The Niwa scientists also compared data from 1997 to 2009 to examine the link between wave heights in the Southern Ocean and sea ice extent. 
‘‘What we’ve found is that where waves have got bigger the sea ice has retreated, and where waves have got smaller the sea ice has expanded,’’ Williams said. 
The research helped to explain why Antarctic sea ice had been increasing in some areas where climate models predicted it would decrease.
So the alarm of decreasing sea ice in Antarctica is just hot air! Now this is also of interest to us remembering
Sir Shackleton's expedition:

The effect of waves on sea ice has been known since the early days of Antarctic exploration. Ernest Shackleton was ‘‘famous for having had his ship trapped in ice’’, Williams said. 
After the men abandoned ship in the Weddell Sea, ‘‘freak waves’’ broke up the ice they had sought safety on. 
Williams said the knowledge could be beneficial for ships that get stuck in sea ice, if they knew there were big waves coming that could break the ice around them. He  said understanding how sea ice expands and retracts was an im important part of climate modelling. 
The connection between waves and ice they confirmed should inspire more interest in measurement ice and waves! Niwa scientists certainly deserve our utmost admiration for their detailed efforts!