|
|
|
|
|||||
|
||||||
From: Margo Dollan (no email)
Date: Tue Jul 27 2004 - 08:14:32 EDT
Hi Ricky!
I'd heard about the Ocean Ranger but had been given different heights (from
80' to 100') for the wave. Was it just one rogue, or was it a "Three
Sisters" phenomenon? Just curious, I'd heard that the first took out the
electronics and the following capsized the rig.
Off the Atlantic coast of Africa there are quite a few reports of large
rogues and I think it has something to do with the way the current runs off
the continental shelf in that part of the world. Anyone know more?
~Margo
----- Original Message -----
From: "Ricky L Carroll" <>
To: <>
Sent: Friday, July 23, 2004 12:46 PM
Subject: Re: [world-cruising] Waves
I may be wrong (okay, it's a SWAG), but I believe that rogue waves are
transient events that occur when wave trains of different periodicity
(frequency) constructively interfere. Surfers use this to a small degree
when predicting "sets" of bigger waves caused when ocean swells come in a
different angles, or when local wave action interacts with nearby land
masses.
Large scale open ocean wave trains that interact to cause these monster
offshore waves would likey be traveling along different paths, but would
still be quite large already. I doubt that a 100' wave will form suddenly
out of 8' seas. More likely, it would form in an area alread stirred up. I
would suspect that amplitudes of 3-5 times the nominal sea state at that
time would be the mostly likely calculable. answer (is calculable a word?).
These wave sets might interact briefly (get in sync or harmony) and cause a
big-daddy of a wave or several. Just a bit later, the interaction would die
as the wave train loses that moment of perfect (or hellish) harmony.
I worked for Ocean Drilling and Exploration Co. in 1983 when the Ocean
Ranger semi-submersible drilling rig went down off Nova Scotia. A massive
wave blasted the portholes to the control room, flooding the computerized
controls to the ballast system. Without the ability--or trained
personnel--to regain manual control, the rig went down in a matter of
minutes. All 83 hands were lost. It was a horrible day for us and our
friends on that rig.
The wave height necessary to simply reach the portholes was over 110'.
Kinda scary.
Ricky
(thanks again for all the advice on the vega in kemah. I'm heading out of
town unexpectedly, but i'll try to take a close look at that boat, if it's
still available, when I get back in about two weeks.)
Robert Gainer <> wrote:
Jim said,
What ever happens to these waves? Don't they have to make landfall at some
point? I am a bit lost as to how this much energy could be dissapated and it
still be such a mystery.
Jim,
When the force (wind) that makes them disappears the internal fiction of the
wave steels all the energy and the wave decreases in height over time until
it reaches land and becomes surf or disappears.
All the best,
Robert Gainer
_________________________________________________________________
Is your PC infected? Get a FREE online computer virus scan from McAfeeŽ
Security. http://clinic.mcafee.com/clinic/ibuy/campaign.asp?cid=3963
Yahoo! Groups Links
[Non-text portions of this message have been removed]
Yahoo! Groups Links
------------------------ Yahoo! Groups Sponsor --------------------~-->
Yahoo! Domains - Claim yours for only $14.70
http://us.click.yahoo.com/Z1wmxD/DREIAA/yQLSAA/A1TolB/TM
--------------------------------------------------------------------~->
Yahoo! Groups Links
<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/world-cruising/
<*> To unsubscribe from this group, send an email to:
<*> Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/
|