Ancient Tides Quite Different From Today

High tide in the Bay of Fundy.

Tucked into a pocket between the Canadian provinces of New Brunswick and Nova Scotia, the Bay of Fundy is famous for having dramatic differences between its high and low tides. In fact, the tides observed here are tied with Ungava Bay (located farther north) for the largest tides on Earth. Under typical conditions, high tide at the head (the most inland part) of the Bay of Fundy is as much as 17 meters (about 56 feet) higher than low tide. Caption and photos source: NASA

Low tide in the Bay of Fundy.

Excerpts; By The Oregon State University, in Science Daily

The ebb and flow of the ocean tides, generally thought to be one of the most predictable forces on Earth, are actually quite variable over long time periods, in ways that have not been adequately accounted for in most evaluations of prehistoric sea level changes.

Geological forces that act over hundreds to millions of years, such as plate tectonics, ice ages, land uplift, erosion and sedimentation, have caused the tides in certain places to vary wildly throughout history, according to a new study lead by David Hill, Oregon State University, and published in the Journal of Geophysical Research.

“Understanding the past will help us better predict tidal changes in the future,” David Hill said. “And there will be changes, even with modest sea level changes like one meter.”…

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