Moon & Tides

We are back - our visitors have left and you can expect at least a post or two a week from me again.

Last week we went to the Parrsboro area, at the head of the Bay of Fundy in Nova Scotia, and visited the fossil cliffs at Joggins, a fascinating UNESCO world heritage site that played an important role in early Darwinian discussions of evolution. We found an Interpretation Centre there that was well worth a visit. We also observed evidence of the highest recorded tides in the world.

It turns out that the Bay of Fundy acts like a big bathtub. When you were in the tub as a child, you probably had fun sloshing the water back and forth to make a wave big enough to splash water out over the end. If you did, you learned you had to give the water a push at just the right times (in resonance with its natural timing) to make the wave big enough. It just happens that the gravity of the moon as it passes over the Bay of Fundy pulls on the water at just the right times to add energy and get the water to slosh into the end of the Bay, giving tides as high as 16 meters (over 52 feet) on occasion!!

The Bay of Fundy with its amazing tides is the only Canadian finalist in the campaign to choose the New Seven Wonders of Nature (winners will be chosen in 2011, and you can vote!). While we were there, someone told me about the effect the incoming tide has in a narrow river at the head of the basin. As the water comes rushing in, it creates a high enough wave that you can ride a raft on it or surf board it quite a distance up the river, depending on the height of the tide that day. The wave is called a tidal bore, but sounds like it would be anything but a bore.Rie