Bay of Fundy tides

The Bay of Fundy is yet another rift basin, which separates New Brunswick from Nova Scotia. It’s famous for its incredible tidal range, which exceeds 15 meters. We didn’t make it all the way to the north end of the bay where the range is the largest, and we didn’t have time to sit through an entire tidal cycle. Even so, the tides are impressive. The image at left shows the Harbor at Saint John about 90 minutes after low tide, as the tide was coming in. The image on the right was taken about 3 hours later, still more than an hour before high tide.

Even at the mouth of the bay there are pretty large tides. Tidal Falls is located in Maine northeast of Acadia National Park (there’s an overlook at 44.520198 N, 68.221869 W). Strong tidal currents flow through this area, complete with rapids. In the video clip below, the ocean is to the right, so the current is flowing away from the ocean on the incoming tide:

One of the major attractions in Saint John is Reversing Falls. During most of the year, the level of the Saint John River is higher than the Bay of Fundy’s low tide, and lower than high tide. That means that as the tide comes in it’s actually higher than the river and the water flows upstream, and that it reverses at low tide. Where the two bodies of water meet there is an almost continuous turbulent rapids. The only time it lets up is during the brief moments each day when the river and bay levels are the same.

Of course, during the spring the river is swollen with runoff from melting snow and rain, so during most of May the river is higher than the bay even at high tide. But you still get the turbulent flow at the boundary of the two bodies of water, with whirlpools and standing waves:

At some point we plan to return to the Bay of Fundy, and spend some time at the north end of the bay observing the entire tidal range.

This entry was posted in General Geology. Bookmark the permalink.

One Response to Bay of Fundy tides

  1. Amanda M. says:

    I am a little late catching up on your latest blogs – the tides up there in Maine/Nova Scotia are one of the neatest things I have ever seen in my life! When you go back up there, a really neat trip is to take the ferry (catamaran) across to Nova Scotia from Bar Harbour. It is a beautiful island, and there is a place you can go to watch the tides (well, there are lots of places, but this one is so cool!). It is a river, that is probably a foot deep, then all of a sudden there is a huge sound and a wall of water comes rushing down the river, along with people in rafts! It is so wild. And you can’t beat the blueberry pie!

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s