NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Wind drift, was: DR thread from Nov-Dec '04
From: Jared Sherman
Date: 2005 Jan 20, 17:02 -0500
From: Jared Sherman
Date: 2005 Jan 20, 17:02 -0500
Bill- <<4. By your definition of seiche, when the wind decreases/stops, gravity once again prevails and the piled up water on the leeward side of the body rushes to the former windward end to establish equilibrium (level off), setting up a wave. 5. If the basin is sympathetic, this "sloshing" may be rather dramatic for a tideless body of water.>> Do you recall the recent reports of the tsunami, where the ocean rose, then fell, then rose again? I suspect what the Annapolis Book is saying may be called seiches in lakes, is not the current itself, but the repeated sloshing of waves back and forth across the body of water, after the wind falls or as it lulls. Once the water piled up "over here" is no longer being wind driven, it will go "back there" and on reaching the opposite shore, it will reflect back and forth again and again, many times, until the water has expended the energy from all that wind. If the motion and the basin were resonant, that would match the definition of seiche as I'd heard it. Why they'd associate a *current* with that...dunno. That's like asking a fisherman what a "blackfish" is. There's a different species going by that same name in every corner of the globe.And latin names don't count--unless one lives in Latinia.