Slack current Vs high/low tide Was Re: WIND_TALK digest 63

From: Jim Paugh (James.Paugh@Eng.Sun.COM-DeleteThis)
Date: Fri Aug 25 1995 - 10:41:45 PDT


Received: from hplms26.hpl.hp.com by opus.hpl.hp.com with SMTP (1.37.109.8/15.5+ECS 3.3+HPL1.1) id AA14429; Fri, 25 Aug 1995 10:48:21 -0700
Return-Path: <James.Paugh@Eng.Sun.COM-DeleteThis>
Received: from mercury.Sun.COM by hplms26.hpl.hp.com with ESMTP ($Revision: 1.36.108.11 $/15.5+ECS 3.3+HPL1.1S) id AA269752963; Fri, 25 Aug 1995 10:49:23 -0700
Received: from Eng.Sun.COM by mercury.Sun.COM (Sun.COM) id KAA21767; Fri, 25 Aug 1995 10:41:15 -0700
Received: from jurassic.Eng.Sun.COM (jurassic-248.Eng.Sun.COM) by Eng.Sun.COM (5.x/SMI-5.3) id AA09004; Fri, 25 Aug 1995 10:40:53 -0700
Received: from jalama.Eng.Sun.COM by jurassic.Eng.Sun.COM (SMI-8.6/SMI-SVR4) id KAA20732; Fri, 25 Aug 1995 10:40:43 -0700
Received: by jalama.Eng.Sun.COM (SMI-8.6.9/SMI-SVR4) id KAA08804; Fri, 25 Aug 1995 10:41:45 -0700
Date: Fri, 25 Aug 1995 10:41:45 -0700
From: James.Paugh@Eng.Sun.COM-DeleteThis (Jim Paugh)
Message-Id: <199508251741.KAA08804@jalama.Eng.Sun.COM-DeleteThis>
To: wind_talk@opus.hpl.hp.com-DeleteThis
Subject: Slack current Vs high/low tide Was Re: WIND_TALK digest 63
X-Sun-Charset: US-ASCII

Ahhh! Finally, an explaination that makes sense to me!

Thanks Bob.

~Jim

> From kasplash@crl.com-DeleteThis Thu Aug 24 23:01:08 1995
> Date: Thu, 24 Aug 1995 22:56:58 -0700
> Originator: wind_talk@opus.hpl.hp.com-DeleteThis
> From: Bob Galvan <kasplash@crl.com-DeleteThis>
> To: Multiple recipients of list <wind_talk@opus.hpl.hp.com-DeleteThis>
> Subject: Re: WIND_TALK digest 63
> X-Listprocessor-Version: 6.0c -- ListProcessor by Anastasios Kotsikonas
> X-Comment: Windsurfing Discussion Mailing List
>
> Jim Paugh asks:
>
> "What I would like to hear is an explanation of why slack current occurs
> after say, a low tide. For instance, today, low tide at Crissy is at
> 5:03pm, but low slack is at 7:29pm! How is it that slack current occurs
> 2.5 hours after low tide? "
>
>
> Bottom Bob replies:
>
> Think of the tides as very long period waves. This tidal wave emanates
> from a node somewhere between Mexico and Hawaii and travels northward toward
> us. The trough is 6 hours behind the crest.
>
> When this wave crest gets to the Golden Gate, it enters and rolls right
> on past Alcatraz, down to the South Bay, up to the North Bay and beyond,
> past Vallejo, Antioch, Sherman Island, Windy Cove and on to Sacramento.
> It takes about five hours to get to Rio after passing the Golden Gate.
>
> So as this wave crest rolls up river, water continues to FLOW into the
> bay/delta system even as the water LEVEL drops at the Gate. The
> flowing water is making the level rise futher up the bay.
>
> Conversely, consider low water at the Gate. Low water at San Rafael is
> an hour later, and low water at Rio is five hours later. So even as the
> tide rises at Crissy, water continues to drain out of the upper bay for
> another 1.5 to 2.5 hours.
>
> Bob Galvan
> kasplash@crl.com-DeleteThis
>
>
> P.S. Going to Maui on Saturday.
>
>
>
>
>
>



This archive was generated by hypermail 2b29 : Mon Dec 10 2001 - 02:30:01 PST