Freak Waves

Sponge Bob

These are not strictly a weather event . A freak wave is where there is a (say) 1 in 1000 chance that a wave will be abnormally large in a given sea state. In a flat calm 24 degrees like today it is possible that somewhere a 3ft wave will form . That is a freak wave ...but nobody will notice.

In a winter sea state the freak wave will be monsterous . The sea state itself is bad enough but the freak wave is a freak relative to the sea state. It is a bleedin monster

This post is about some of these events that maye be of interest . My personal view is that we are overdue a big one ...as are we overdue a strong solar storm not unlike the Carrington Event ...and we possibly even overdue a tsunami .

Horizon did a program some years back on freak waves, summarised here.

The best example they gave ( of immediate concern) was the Draupner Wave , a 26.6m pussycat that passed under a platform in the North sea . The draupner wave is of most interest because it was captured on radar and because we therefore know the shape of freak waves .

http://en.wikipedia.org/wiki/Draupner_wave

But it is a pussycat !!!

Around the same time The Fastnet Lighthouse was smacked by a much larger wave .

The light on the Fastnet Lighthouse is 48.5m above sea level

http://en.wikipedia.org/wiki/Fastnet_Rock



and yet , as the Economist documented last December a freak wave hit it while it was manned

In stormy winter weather, the “big seas would come sailing up over the entire building like the field of horses in the Grand National,” as one former Fastnet keeper put it. Sometimes, there were almost disastrous consequences; Mr O’Driscoll remembers a storm in 1985 when a wave reached as high as the light and came crashing through the glass, overturning the vat of mercury and sending the poisonous liquid pouring down the stairs. He doubts the tower would have withstood another wallop as great as that, but it never came. Suddenly, there was a great calmness.

It wasn't that 1985 was in some way exceptional. My next example comes from a history of the island of Mingulay which is in the outer Hebrides . South of it lies Geirum Mór , Geirum Mór has a height of 51m . One day the locals went out after a storm to find that all the sheep had been washed off the island by a wave . That was in 1868 .

On Flannan Isles just off the NW coast of the Outer Hebrides there were two events in December 1900. The first was documented by the lighthouse keepers who lived there.

http://en.wikipedia.org/wiki/Flannan_Isles#Mystery_of_1900

On top of the cliff at over 60 metres (200 ft) above sea level turf had been ripped away over 10 metres (33 ft) from the cliff edge.

The next event killed the poor bastards shortly afterwards , a matter of days at most . It may or may nopt have been another biggie.

However the BIG DADDY of the lot happened in Mayo . It smashed into a lighthouse on Eagle Island and luckily for the lighthouse keepers there were two lighthouses on Eagle Island .

The wave smashed the light on top of the lighthouse and poured into the lighthouse and down the stairs ....turning the lower levels into a swimming pool .

Were it not for the lighthouse keepers from the other lighthouse drilling holes in the door to drain the water the keepers may have starved to death in there .

The Eagle Island West Lighthouse was 68m above sea level .

http://cil2.adnet.ie/index.php3?LighthouseID=34

On the 11th March 1861 at midday the light room of the East tower was struck by the sea smashing 23 panes, washing some of the lamps down the stairs, and damaging the reflectors with broken glass beyond repair. It must have been an incredible wave to have come up 133 feet of rock and then a further 87 feet of lighthouse tower to cause so much damage. In spite of the efforts of the Keepers to repair the damage it wasn't until the night of the 12th that the light was restored and then only with 12 lamps and reflectors. Another interesting aspect of this disaster was that so much water cascaded down the tower it was impossible for the Keepers to open the door of the tower. They had to drill holes in the door to let the water out.

It took a few more hits over the years, This 68m above sea level structure was eventually abandoned.

Don't even start me on the Giant Boulders 25m above sea level on the Aran Islands

http://www.guardian.co.uk/science/2004/aug/18/environment.research

M.T. Cranium

Yes, I've heard similar reports of what are called "rogue waves" on both the Pacific and Atlantic coasts of Canada, and even on Lake Superior.

I believe they are caused when a very strong storm some distance offshore has sent its wave field into an already chaotic sea state near shore. The irregularity of the waves from the two regimes gives some theoretically very large superimposed waves as a result.

These are to be distinguished from high swells or storm surges when the whole sea surface is raised 5-10 metres.

There are warnings on the west coast of Vancouver Island for people to be wary of "rogue waves" even in calm or choppy conditions, the Pacific has such vast reaches that on occasion, rogue waves have suddenly swept tourists to their deaths on nearly calm days, as they walk around the rocky shorelines of national parks in that area.

The wave that sank the Andrea Gale in the "perfect storm" off Nova Scotia in October, 1991 was thought to be 20 metres high and a form of freak or extreme wave as well.

ronbyrne2005

I saw that horizon documentary. Dont think anything over 30metres is possible without collapsing.

kindredspirit

We were hit by a rogue wave off Kerry Head nine years ago.

A very large fishing boat nearby had ALL it engine mountings broken by that wave. I thought our boat had broken its back after it fell off the top of the wave but it survived unscathed.

I never, ever, want to see a rogue wave again. It kept mounting and mounting and mounting up. You wouldn't believe it normally but we saw and experienced it with our own eyes. I've also heard that they've broken oil tankers in half.

Mr Benevolent

1 in 1000

That means there's one every few minutes somewhere on the planet. Even 1 in 10,000 or 100,000 means big trouble.

Dont think anything over 30metres is possible without collapsing.

There have been waves recorded at least 20% higher than that. Besides, a 30m wave is HUGE.

Sponge Bob

Confab wrote: »

There have been waves recorded at least 20% higher than that. Besides, a 30m wave is HUGE.

I think I explained quite clearly that 60m is possible albeit in a stormy sea state and that would be 100% bigger not 20% bigger .

It does give an idea of the difficulty of offshore wind projects and the scale of the turbines required to survives these waves .

The hub height may have to be minimum 80m if they are not to be washed over by these thumpers or bent out of whack , or smacked by a very large rock thrown up by one .

cian1500ww

Seen a documentary on them a while back, certainly are very frightening sights. Has there been many recorded in Irish waters ?

Sponge Bob

Bumping this because some 20m high sprat of a thing was recorded off Donegal yesterday.

muckish

Is there not a difference between a wave height that has been recorded in open sea as opposed to one that has begun to feel the effects of the shore and started to rear up? So that wave that dwarfed the Lighthouse at Eagle Island, what would it have measured in open water if there had been a buoy there?

irish1967

Maybe I am over sceptical but isn't it a co-incidence that with only about 2 weeks funding confirmed on the buoys they suddenly get worldwide coverage thanks to this big wave.
Their contribution to big wave surfing tourism has earned them enough money in one day to find them for years

rhonin

Here is a picture (not mine) of eagle island. It's not far from Erris Head and does get the full force of the Atlantic. I have been on a good few boat fishing trips there. Can you imagine how scary it must have been for the keepers when that wave hit?

Popoutman

Looking at the profile of Eagle Island - it's not really that surprising that the lighthouse was hit by the meat of a wave. The island forms a lovely ramp up to the base of the lighthouse, which being fairly short, would allow a 'heavy' 15m wave to run up the rocks and hit the top of the lighthouse itself. Maybe the lighthouse should have been another 15m taller - may not have had the same level of problems.

Popoutman

http://www.esa.int/esaCP/SEMOKQL26WD_index_0.html

ESA article on satellite coverage of "rogue waves"

blackius

A good few years ago,I was in a small boat [think punt] fishing about a mile off the coast in the irish sea when we spotted a huge rolling wave in the distance heading straight for us.
The sea had been flattish calm and there was no wind to speak of.
I'd say we dipped maybe 15ft when we rolled over it.
T'was scarey at the time.

stevenmu

I can't find it now online, but an article in yesterdays Indo mentioned that there was a wave of 20.2m only an hour or two before, so that would sounds to me like the record breaker yesterday wasn't a true rogue/freak wave.

Coles

They happen in the Irish Sea too. The MV Swanland was sunk by a freak wave off the coast of Holyhead two weeks ago.

Link to the Telegraph and interview with Coastguard

V_Moth

Popoutman wrote: »

http://www.esa.int/esaCP/SEMOKQL26WD_index_0.html

ESA article on satellite coverage of "rogue waves"

The article claims that 200 large ships have been sunk by rogue waves, which is a completely baseless claim. One of the very few cases of a rogue wave causing the sinking of a large ship was the MV Muenchen.

A couple of youtube vids of freak waves:

https://www.youtube.com/watch?v=l_8hOai9hGQ

https://www.youtube.com/watch?v=_akyfMp9ln8

https://www.youtube.com/watch?v=VchsHhPIx_s

And just to compare, probably the only at sea footage of a tsunami:

https://www.youtube.com/watch?v=OdhfV-8dbCE

snubbleste

As posted in another thread Guardian - Transatlantic rowers rescued after boat is struck by 'enormous wave'

"The ocean was quite calm. We were in great spirits after the first eight days in the race. Suddenly our boat was rocked by an enormous wave, the size of which we've never seen before. Our boat was thrown over and capsized. The cabin flooded.

Irelandcool

I think my stomach would handle rough seas but rogue waves kinda keep me out of the ocean. Just the idea a wall a of water that is 30 metres high can appear just from nowhere is a pretty terrifying thought.

Irelandcool

Do you think there is should be better emphasis on creating awareness of freak waves in the country in Ireland? Especially after the three people were killed last week by one.

Coles

Here's a good read about 'freak waves'.

http://loneswimmer.com/2013/03/19/theres-no-such-thing-as-a-freak-wave-coastal-safety-is-your-own-responsibility/

W1ll1s

Megatsunami - Lituya Bay, Alaska

Triggered by a 90 million ton Rockslide.

1722ft runup on land.

This event forced a re-evaluation of large wave events and recognition of the impact of rockfall and landslide's as a previously unknown cause of VERY large waves...

sryanbruen

When I was at the closest shore to my area today, I haven't seen such waves since February 2014. Jesus they are clearly "Freak Waves".

Tabnabs

sryanbruen wrote: »

When I was at the closest shore to my area today, I haven't seen such waves since February 2014. Jesus they are clearly "Freak Waves".

Unlikely, that's just a huge swell caused by a very large storm. Not every big wave is a "freak wave". I've experienced them off South Africa in the Agulhas Current. It's not necessarily the height of the wave that's the issue, but the mass of water contained within it. It comes out of nowhere, you fall into the trough and then it wallops you hard.