Rapids rushing up the Saint John River, New Brunswick, Canada |
My friend and fellow
children’s book author Caroline Hatton visited the Bay of Fundy in New
Brunswick, Canada, in October 2014. She took the photos and the video in this
post.
Whitewater rapids caused by rising tides reversing the flow of a river?
I had to see this. I had long known, from nature documentaries, about the world’s highest tides in the Bay of Fundy.
But all I had seen was time-lapse videos of the corresponding, extreme ebbing tides lowering fishing boats the height of a five-story building, so that the boats had to be on extra
long tethers to avoid dangling vertically like dead fish on a hook.
Weeks before
traveling to the Bay of Fundy, I listed the “Reversing Rapids”
(in Saint John, New Brunswick) on my itinerary and googled Saint John Tide Times.
Once in Saint John, I arrived at Fallsview Park on Fallsview Avenue in time for
the high tide.
Red dot: location of Saint John in the Bay of Fundy |
Tourists
weren’t the only ones lining up to attend nature’s show. Cormorants also
gathered on a small, rocky island in the river.
Here's my video of rapids rushing up the Saint John
River:
The video
shows the Saint John River, a church steeple on the opposite river bank, and
the tips of two small islands. Left is down the river toward the Bay of Fundy.
Right is up the river. In the few hours before I recorded the video, the tide
had risen higher than the river
level, gradually reversing the direction in which the water flowed. The narrow
rocky gorge at this spot on the river squeezed this enormous volume of sea
water, the same way a nozzle would. This created whitewater rapids, which
peaked at high tide, the time of the video. Twice a day, the effects of the
high tide can be felt more than 80 miles (~ 127 km) inland!
The
cormorants, uninhibited by the violent whirlpools and churning foam, repeatedly
flew up the water flow, plopped down, and dove out of sight to catch what must
have been fish swept inland by the high tide. The birds resurfaced too far for
me to tell whether they were visibly fatter.
After I left,
the reverse flow would have slowed down as the sea water level began to go down.
The sea and river water levels would have become equal, making the river look
like a motionless pool for about 20 minutes between the high and low tide
(slack tide). As the sea level dropped below the river level, the flow down the
river would have grown stronger, until rapids rushed down the river at low tide.
The flow down the river would have slowed until the next slack tide half-way to
the next high tide. And this cycle of “Reversing Rapids” repeats itself twice a
day.
Fern Fossil, New Brunswick Museum, Saint John |
Instead of
watching the complete cycle, I enjoyed learning more at the Saint John InformationVisitor Centre, seeing fossils and art at the New Brunswick Museum, and shopping
indoor at St John’s City Market.
Saint John’s City Market |
For more
info:
Caroline Hatton's post about the tidal bore at Truro near the Bay of
Fundy. https://theintrepidtourist.blogspot.com/2017/11/canadas-bay-of-fundy-watch-tidal-bore.html
Caroline Hatton's post about the collapse of The Hole on Long Island in
the Bay of Fundy. https://theintrepidtourist.blogspot.com/2017/11/canadas-bay-of-fundy-about-hole-that.html
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