Weather Extremes

It was a fascinating book. One of the science oriented cable channels had an hour on the subject some time ago. Some areas prone to it by virtue of currents and subsurface topography in combination with surface storms. Much of it random. Weather deaths occur annually from highly localized random events, ie lightining strikes. Mass deaths, ie tsunamis, are major news stories. A lost freighter less so just like a lightning fatality. The inability to control/predict perhaps makes it uneasy news. Insurers can deal with it in actuarial terms and it becomes a cost of doing business, just as road accident probabilities are built into trucking costs. As to the surfers, like the Everest summitters, they do it because it is there.

Really interesting blog post -- thank you :)

Just wanted to raise one additional cause of giant waves -- impact created Tsunamis. While clearly these won't happen as often as those generated by Earthquakes, they have the potential to be much, much bigger. In fact, I read recently about ongoing collaborative research looking at (I think) Japanese Tsunami records, attempting to tie them to specific Earthquakes, with the subtext that any that could not be linked to a given event could be impact generated.

Can't find a link to the work at the moment, but this site (http://users.tpg.com.au/users/tps-seti/spacegd7.h tml ) appears to have a bit of information on that side of things!

My recollection was that something like 1/3rd of Tsunamis recorded in Japan in the last few hundred years (Japan was used because it had the longest and most accurate record) had no known progenitor earthquake. While that doesn't mean they weren't caused by unknown earthquakes, it's a tantalising pointer (if my hazy recollections on the numbers are true) to the possibility that at least some could be the result of small impact events in the pacific... certainly given the amount of small objects out there it isn't beyond the bounds of possibility!

I was watching a show on rouge waves a few months ago on either discovery or national geographic and one of the reasons they gave for the rouge waves are caused by underlying currents with strong non-storm winds coming from the opposite direction.

A specific example they gave was the Agulhas current off the SE coast of South Africa which parallels the coast and runs from NE to SW.. However, the prevailing winds in the region run from SW to NE after a cold front. This shearing between the winds and the current is what may have caused the non-storm rouge waves.

Could a rogue wave hit land and cause damage similar to a tsunami?

surfing the north shore in hawaii always had to keep an eye out for freak large sets. they'd come out of no where and catch everyone inside generally put a pounding on everyone.

I have read both books listed as references. Both very good reads. In fact, "The Power of the Sea" may be one of the best books I have ever read. The stories about the human impact of the tsunamis and rogue waves (not to mention the storm surges, deadliest of all) are incredible, and the science behind them is explained more clearly than anything I have ever read (and without sounding like a textbook). Buy them both.

The Alaska event was delineated years ago in a great book called The Elements Rage, published in 1965 and written by Frank Lane. I first read it as a teenager in the local public library, already a weather enthusiast with the full array of home instrumentation at the time. A few copies still available on Amazon.

I saw this article, too, and thought it fascinating. I am looking for a good book, not too scientifically detailed, on the magnetic drift and shift. The magnetic drift has been moving faster during the past few years and is now moving 40 miles/year. Many navigational maps have had to be redrawn due to this drift. If you see anything please let me know.

Quoting tngardener:
I saw this article, too, and thought it fascinating. I am looking for a good book, not too scientifically detailed, on the magnetic drift and shift. The magnetic drift has been moving faster during the past few years and is now moving 40 miles/year. Many navigational maps have had to be redrawn due to this drift. If you see anything please let me know.

It may be hard to find info on the drift.... not much interest in it since almost everyone uses electronic navigation aids! ...I cant help you, but good luck.

The BIG splash will be generated by the asteroid that lands in Earth's oceans. The amplitude of the subsequent wave train will dwarf anything ever seen by humans. A lesser but still deadly and widespread East coast North America splash will result from a landslide in the Canary Islands where there is unstable geology. These events - and the Lituya event - were modeled years ago by one of the National Labs.

A note of correction: storm surge is NOT a "wall of water", it is more nearly a wave of long wavelength. Tides and storm surges are of similar order of wavelength.

Quoting HurricaneKatrina:
Could a rogue wave hit land and cause damage similar to a tsunami?

Rogue waves are usually thought to be "beats" where two or more trains of waves are crossing.

Have you ever listened to someone tuning a guitar by fretting a lower string and plucking the fretted lower string and the string being tuned and listening to the beat (the sound getting stronger and weaker) as the tuned string gets closer to the same frequency as the fretted string? As the strings get closer in frequency, the beat gets slower and slower.

Waves in the ocean beat against each other as well. As two (or more) waves arrive at the same location, they can add to, subtract from, or neutralize each other. If two 40' waves cross the same point, they will add up to a 80' wave. This is a momentary thing if they are crossing at close to right angles. But, if they are crossing at a shallow angle like 5 or 10 or 15 degrees, the added-up wave can persist for seconds or even minutes. It's a big ocean, so the few places where this happens are rare compared to the rest of the ocean where waves are normally sized.

With more large ships (which can survive these rogue waves) traveling the ocean, more and more of them are reported. At one time rogue waves were thought to be exaggerated "sailors' stories", but people who can accurately describe and estimate the size of rogues are seeing them and reporting back.

Because they are so rare, the chances of a really big one forming at exactly the time it reaches a shoreline is even rarer. So, while this must happen occasionally, the chances of someone seeing it and being able to accurately describe it or estimate its height is rarer still.

As far as shore damage: since rogues are formed by two waves crossing, they are limited in length. A tsunami is long and almost straight when it hits a distant shore. The rogue wave is short and while it may put a lot of water on the shore at one place it can spread sideways as well as inland. The tsunami is putting a lot of water ashore everywhere so it is all forced inland where it causes damage as it comes inland, and again as it flows back to the ocean.

Fascinating stuff. Thanks for starting this mini-blog.

As far as biggest surf waves are concerned, I feel this blog doesn't do the subject justice. There are many many big wave surfing spots all around the world capable of handling waves of over 60ft outside of N America and Hawaii.

Here is a list of as many big wave spots that I am aware of:


N AMERICA:

-Cortes Bank
-Ghost Trees
-Mavericks
-Nelscott Reef
-Todos Santos

Hawaii:
-Peahi (Jaws)
-Outer Log Cabins
-Waimea Bay
-Kaena Point
-Makaha


S AMERICA:

-Punta De Lobos, Chile


AFRICA:

-Dungeons, South Africa


AUSTRALIA

-Cow Bombie
-Margaret River


EUROPE:

France:
-Belharra

Spain:
-Playa Gris
-Asturias

Irland:
-Aileens or Aill Na Searrach Ireland
-Mullaghmore Head
-Prowlers





The main reason there are so many more big wave surfing spots in N America and Hawaii is because surfing is so popular in hear areas that almost no waves go by unnoticed.

AS FOR ACTUAL SURF RECORDS:

The biggest wave ever Surfed: Estimated 85ft wave Surfed by Ken Bradshaw at Outer Log Cabins, Oahu, Hawaii.

Image:



Biggest surf wave ever photographed (not actually ridden or Surfed): Estimated 100ft wave at Kaena Point, Oahu, Hawaii during the nicknamed "storm of the century" on December 4, 1969. Also at Mavericks, California there was a claimed 100ft set of that came through on Nov 21, 2001 known as "100ft Wednesday." This Mavericks report was never photographed, it was simply anecdotal evidence.

100ft wave at Kaena Point phtographed by Greg Noll



Surf break capable of largest surf: This subject is debated, and not well known. The reason being is because swells rarely ever get large enough to know how the surf spot would handle 80ft surf. But a few safe guesses would be Cortes Bank, Mavericks, and a few select Hawaiian surf breaks since all these breaks have seen 80ft surf.




If anyone doesn't believe the validity of the stuff I am posting, feel free to do your own research, Google any of the things I mentioned, you will find plenty of evidence and proof.