A tidal wave or bore is the leading edge of the incoming tide, in a narrow estuary. This may be one, on the Piscataqua river between New Hampshire and Maine, USA, which has very swift tidal currents.
Tidal wave?
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By AlejoHausner @ 2007-02-04 15:27:02
mstoess
@ 2007-02-05 14:22:23
Lets try to prove it. What is there to be said for a tidal wave?
AlejoHausner
@ 2007-02-05 21:56:06
Well, wikipedia says that tidal waves are formed by the incoming water of the rising tide. Usually tides take 6 hours to rise fully, on the open coast, but in an narrowing estuary the water can bunch up and actually form a sudden step. This is not a boat wake (too wiggly), and it goes all the way across the river, so it does suggest the whole river depth is changing. However, I'm not 100% convinced that this is indeed a tidal wave, because of the lighting. I get the feeling that there's a slight brightness gradient across the edge, brighter on the right side (South-East), which means that the water on the left (up-stream) side is higher. This contradicts what I read, that the incoming tide causes tidal bores. The Piscataqua river is known for very fast currents (due to tides), although I don't know if that argues for or against tidal waves. I will ask a local expert and let you know what I learn.
AlejoHausner
@ 2007-02-06 19:33:02
Well, my expert says he's never heard of a tidal bore on the Piscataqua, so it's probably not that.