Talk:Rip current

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The lifeguard page linked says "The United States Lifesaving Association estimates that the annual number of deaths due to rip currents on our nation's beaches exceeds 100", while the wikipedia page says 1000 deaths/year. Presumably this should be changed. —Preceding unsigned comment added by 70.110.227.93 (talk • contribs)

Yes, 1000 deaths, or even 100 are far too many. We should we everything possible to change this situation and make more swimmers aware of the dangers of entering the water! Ewlyahoocom 01:57, 27 April 2006 (UTC)

-I changed the passage that suggested that undertow and rip tide are incorrect terms. I hate it when people say what terms are somehow incorrect, by that logic most words are incorrect since they don't litterally represent what they are named after.- —Preceding unsigned comment added by Julian Diamond (talk • contribs)

Contents

[edit] Dangers

"A common misconception is that a rip occurring under the water, instead of on top — an undertow — is strong enough to drag people under the water; this is not true."

I don't think this statement is true. I've been in each of the Great Lakes during high waves (+2m) and I can tell you without hesitation that the "undertow" effect can most certainly pull a person off their feet if standing in the water, and quite possibly under the surface if one is not prepared. —Preceding unsigned comment added by 70.50.23.9 (talk • contribs)

[edit] Undertow

  • Undertow is a misnomer for a rip current, sort of like calling a tornado a twister (but worse..). The reference of the phrase "undertow" to the phoneme of a rip current is discouraged. 71.200.92.220 01:36, 9 April 2007 (UTC)


Can someone who knows please add a real section about Undertow? Undertow is a disambiguation page which (wrongly or rightly) suggests Rip current.

  • http://www.ripcurrents.noaa.gov/glossary.shtml writes: "Undertow: There is spirited discussion and disagreement among coastal scientists on the existence of a nearshore process called "undertow," and hence there is not an agreed on definition for this word. Undertow is a term often and incorrectly used for rip currents. The best explanation for what many people attribute to "undertow" is as follows: After a wave breaks and runs up the beach, most of the water flows seaward; this "backwash" of water can trip waders, move them seaward, and make them susceptible to immersion from the next incoming wave; however, there is no surf zone force that pulls people under the water";
  • http://www.usla.org/ripcurrents/glossary.asp offers the more concise: "Undertow: Different than a Rip Current!"

Thanks! Ewlyahoocom 01:57, 27 April 2006 (UTC)

As waves propagate toward shore, there is a net shoreward mass transport (called Stokes drift) which occurs between crest and trough. As the wave breaks, the mass transport is increased. The return current is distributed between the bottom and the trough of the wave. When averaged over a wave period, this is what is typically called the "undertow". The difference between this and rip currents is that an undertow will always occur - it is simply a consequence of the mass balance. When the surf is very energetic, the undertow increases in strength correspondingly. Rip currents, however, depend on spatial variability in breaking to occur. Jmkstrat 00:46, 13 June 2007 (UTC)

Backwash Current The receding swash on the beach face, after a wavebreaks, joins the seaward movement of the wave trough tword the next incoming crest. The same orbital wave movement that causes a ball to bob up and down on the water causes the trough to move back and up toward the next wave crest. This is not what the word "undertow" suggests, and this term should not be used.

Seaward Currents This is an umbrella term that excludes only littoral currents. All surf zone currents are either littoral (along the shore) or seaward (away from shore).

[edit] Causes and occurrence

I added a brief paragraph explaining the rip current mechanism in terms of radiation stress. Jmkstrat 00:48, 13 June 2007 (UTC)

[edit] Deletions

I think that the third paragraph under Dangers should be deleted, as it is redundant and unnecessary, and appears to be taken from a news article and is not written in encyclopedic style. MHKathmandu 22:38, 22 June 2007 (UTC)