HERE is an article, from a rather doubtful source, recounting an incident involving giant “mystery waves”, huge waves that are all out of proportion to the water around them.
There are also said to be giant waves of mysterious origin in the Great Lakes of North America.
Does anybody have any info on these or closely related phenomina?
I don’t know about the “geysers” reported in that tale, but rogue waves would seem to be a similar phenomenon. Rogue waves are single waves much larger than the surrounding seas. They may result from undersea events like landslides, but I think they’re more properly called tsunami in that case. Another cause of rogue waves may be constructive interference when you have two superimposed wave patterns. legion’s second link lists more exotic causes.
I think I saw that documentary on rogue ocean waves, which the link summarizes accurately. I’ve nothing to add there. With respect to Great Lakes waves, I believe the OP is referring to seiches, which Lake Michigan is particularly prone to due to its shape.
Seiches are rare. When there’s an unusual combination of winds and air pressures, water is driven to one side of the lake. It then flows back and forth in a rise/recede pattern. (Something similar often occurs in a bathtub when water is displaced on one side.) Usually, seiches aren’t even noticed. But sometimes, the wind pattern reinforces the pattern, and the size of the wave grows as it rocks back and forth across the lake. Given the side of the lake, the frequency of the wave is low.
So if you are fishing on a dock in Lake Michigan, and you notice that the water level is suddenly dropping, you should pack up your gear and leave. You’ve probably got at least an hour before you need to worry, though.
Newpaper article about 1954 seiche that killed several: http://www.kacm.com/Tidalwave.htm
Given the size of the lake. Urg.
Remember that ocean waves behave more or less exactly according to Fourier principles. Many waves are low, but if you get the crests of several in the same place at the same time, their heights simply add up.
Since tsunamis were mentioned, it’s worth noting that until they get close to shore (“tsunami” can be translated from the Japanese as “harbor wave”), tsunamis are very fast waves that are so short and at such a low frequency that they are essentially unnoticeable.
Something about the way the shock wave from the earthquake focus interacts with the fluid dynamics of the ocean means that the energy of a tsunami is extremely spread out. The distance between troughs can be miles, and the wave heights are miniscule. The waves move very fast, however. When the shoreline begins to rise, the shallower water slows the front of the wave down, which cause it to essentially back up on itself, making rise to great heights almost instantaneously.
Has noone thought to blame Godzilla yet?
According to this site, a tsunami can be classified as a soliton wave.
Soliton waves can probably jump in size quite easily as shown here.
[ol]
[li]Thank you for all your help, I appreciate it.[/li][li]Keep chiming in, you might have something to report the rest of us haven’t heard yet.[/li][li]Hi Opal Wanna go swimming?[/li][li]Regarding Godzilla–it wasn’t him. He was in Tokyo, shacked up with his hootchie.[/li][/ol]
A Picture of said Hootchie. She’s a lawyer. Name’s Ally McGrowl.
They met after Alanna Wolff and Jeff Byrd, Counselors of the Macabre, were all booked up. | Published by Exhibit A Press
It is thought a combination of weather-generated large waves and internal flooding caused the Edmund Fitzgerald to go down on Lake Superior on November 10, 1975.
FWIW, the BBC Horizon programme that legion’s linked to argued that the exceptionally large waves that have been reported occur because this assumption of linearity isn’t quite true. The suggested explanation was that large waves are described by the non-linear Schrodinger equation, so that multiple waves can interact in ways more complicated than a simple superposition. You can read their experts explain the theory towards the end of the programme transcript.
Personally, I thought that that portion of the documentary was trying to get too much mileage out of an alleged link to quantum mechanics. Sure, the non-linear Schrodinger equation is related to the linear one that’s at the heart of QM, but I suspect most mathematical physicists actually think of it as just another relatively simple example of a non-linear differential equation.
Whether there were any other grounds for believing that the equation could be applied to ocean waves wasn’t at all clear from the programme.
I suppose you could even say that this bit was overly “sexed-up”.
On a related note, the horror author William Hope Hodgson spent several years at sea. I forget the details, but he’s mentioned what he called the “vertical sea” or “vertical ocean” that occurred in the middle of storms–apparently rather than waves traveling with the wind, under the right conditions they would just swell up vertically to extraordinary heights. This form of wave behavior was much more dreaded than the standard storm waves.
I of course have no objective proof of this, but considering that it took ages to get objective data about rogue waves (I imagine the phenomena are related), I’m not especially inclined to doubt Hodgson. Apparently one of his hobbies was taking photographs of storms and lightning, so he would have had plenty of opportunity to observe these conditions.
Hell’s bells:
Copyright 2004 The Federal Capital Press of Australia Pty Limited
Canberra Times (Australia)
April 12, 2004 Monday Final Edition
SECTION: A; Pg. 14
LENGTH: 487 words
HEADLINE: Biggest wave recorded went unseen THE READ
BYLINE: Scott Radway
BODY:
T HE BIGGEST ocean wave recorded yet - a mammoth 170m high - has been documented off the tiny, low-lying Western Pacific nation of Palau by two scientists studying seawater temperatures.
“It was 170m high, but you will never see it,” says Patrick Colin, director of the Coral Reef Research Foundation based in Palau.
The rogue wave struck on March 28, 2001, but there were no washed-out villages or land devastation.
The wave was entirely underwater and its major effect was rapidly changing seawater temperatures.
Colin says the implications of the findings about deep-water internal waves are “altering our thinking about how coral reefs maintain themselves”.
Coral reefs are bustling homes to sea life in the middle of oceanic deserts.
Ocean water in the tropics is clear because it lacks nutrients - the basic building blocks of sea life - but at the same time, coral reefs flourish.
Some scientists have theorised that the reefs somehow recycle what little nutrients are available, while others have proposed that nutrient-rich water from deep sea is carried up to the reefs to aid growth.
Internal waves now appear to be a likely engine for the latter theory, carrying up cold water packed with nutrients on their towering crests to feed shallow reefs.Eric Wolanski, a physical oceanographer from the Australian Institute of Marine Science, who has been working with Colin over the last year to decipher his findings, says large internal waves could explain why places like Palau have such robust reefs. Colin originally set out to record seawater temperature cycles at varying depths around Palau in order to better understand the 1998 global coral bleaching when rises in surface seawater temperature saw more coral die world-wide - and turn stark white - than ever before in a single event.
In the first six months of collecting data across Palau, Colin was struck by the rapid changes in temperature he found at greater depths that could only be caused by large movements of water up and down, or internal waves.
“There is very little known about internal waves in the tropics, so there is a lot of potential for research,” Colin says.
The waves are found at depths where two layers of water of different densities, determined by their temperature, interface.Rather than cause crashing movements or strong currents, the impact is on the temperature as the colder water goes up and down.
In the case of the 170m wave, Wolanski says the temperature altered from 28C down to 8.5C then back to 28C in 90 minutes.
Waves on the Palau reefs normally range from 50m to 100m, with a usual temperature change of up to 10C.
In trying to ascertain what creates the internal waves, Wolanski and Colin say their data has ruled out lunar tides and passing storms.
Instead, they argue that ocean currents are responsible.
“Like a stone in a stream,” Colin says. “The waves emanate from Palau.” - AAP
I do. Don’t you?
All those moments…
