NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: New Moon, Perigee, and Solstice
From: Frank Reed CT
Date: 2003 Dec 24, 02:53 EST
From: Frank Reed CT
Date: 2003 Dec 24, 02:53 EST
Trevor K you wrote:
"On the effects of a tidal barrage at the head of Fundy: I'm not sure
that anyone really knows what it would do to amplitudes elsewhere."
Then you would be pleasantly surprised. These calculations were do-able even thirty or forty years ago. Today, numerical integrations of the complete PDEs can yield predictions of the tide behavior that you would really have to work to fault. Yes, you can confidently predict the effect hundreds of miles away of a tidal power dam in the Bay of Fundy.
And:
" I can say that the marine geologists here have recently found active erosion
of the seabed in the Bay. One possible explanation is that the system is
gradually getting nearer to perfect resonance with the semi-diurnal
lunar tide (the likely cause being isostatic rebound, which is lifting
the New Brunswick side of the bay, while dipping the Atlantic coast
of Nova Scotia into the sea -- though the blockage of various tidal
rivers by road causeways might be contributing)."
Also, don't forget that the tides themselves are a massive force of erosion. A situation like the Bay of Fundy does not last long on a geological time scale. The tides will slice right through that isthmus in New Brunswick (?? pardon my ignorance of Canadian province boundaries) in a few thousand years.
And you wrote
"This week, I am trying to make sense of a data set which may provide a
bit more information on the effects of the fishing gear (though on the
seabed biota rather than the seabed itself). "
Seabed biota.... Drool.... I love that stuff. Do you get Limulus (horseshoe crabs) up there?
Frank E. Reed
[X] Mystic, Connecticut
[ ] Chicago, Illinois
"On the effects of a tidal barrage at the head of Fundy: I'm not sure
that anyone really knows what it would do to amplitudes elsewhere."
Then you would be pleasantly surprised. These calculations were do-able even thirty or forty years ago. Today, numerical integrations of the complete PDEs can yield predictions of the tide behavior that you would really have to work to fault. Yes, you can confidently predict the effect hundreds of miles away of a tidal power dam in the Bay of Fundy.
And:
" I can say that the marine geologists here have recently found active erosion
of the seabed in the Bay. One possible explanation is that the system is
gradually getting nearer to perfect resonance with the semi-diurnal
lunar tide (the likely cause being isostatic rebound, which is lifting
the New Brunswick side of the bay, while dipping the Atlantic coast
of Nova Scotia into the sea -- though the blockage of various tidal
rivers by road causeways might be contributing)."
Also, don't forget that the tides themselves are a massive force of erosion. A situation like the Bay of Fundy does not last long on a geological time scale. The tides will slice right through that isthmus in New Brunswick (?? pardon my ignorance of Canadian province boundaries) in a few thousand years.
And you wrote
"This week, I am trying to make sense of a data set which may provide a
bit more information on the effects of the fishing gear (though on the
seabed biota rather than the seabed itself). "
Seabed biota.... Drool.... I love that stuff. Do you get Limulus (horseshoe crabs) up there?
Frank E. Reed
[X] Mystic, Connecticut
[ ] Chicago, Illinois
