Did You Know That with Alan Walter
I often pay a visit to see the Joggins Fossil Cliffs. If I’m lucky, I get to see the latest fossilized tree trunk that has been exposed in the cliffs by the Fundy tides.
I still get a charge out of seeing the remains of something that was alive around three hundred million years ago. But more enjoyable to me is to imagine, while I’m there, what our planet Earth looked like back then.
At that time, there were no continents as we know them now. No North or South America. No Asia or Africa. No Europe. Just one massive continent that the geologists call “Pangea,” from the Greek, meaning “one land.” This land mass was surrounded by a single ocean. It took long periods of time before Pangea eventually broke up into the arrangement of continents we see today.
Our piece of territory on that single land mass was directly on the equator at that time. Yes, it was very hot in “Cumberland County” back then, with frequent monsoons and periodic flooding of seawater from the surrounding ocean. This is where the Pugwash salt mines came from. Bays of trapped salt water, baking under the sun, were continually replenished with fresh flooding as the earth’s crust was in motion.
While there were acres of species of trees that would look very strange to us now, there were no flowering plants or grasses. They would not make their appearance on Earth for another hundred and fifty million years or so. Animal life was limited to fish, amphibians and small reptiles. Even the larger dinosaurs had not made their appearance yet.
Most interesting to me is the curious feature of shorter days, and more days in the year, that was part of life back then.
To explain this, it’s been found that the friction on the earth produced by the oceans tides gradually slows down the earth’s rotation over time. This has been going on for as long as we have had a moon and oceans that the moon’s gravity can tug at.
This slowdown is not noticeable to us of course, but the length of a day continues to increase by about two seconds every 100,000 years. Going back over 300 million years it works out that each day was then shorter at 22 hours long. Since the duration of a year - the time it takes the earth to circle the sun - doesn’t change over time there were around 400 days of 22 hours duration in that one-year period. Who knew?
So, when you take that next trip to Joggins and look at the cliffs, think about what kind of a world it truly was back then.
Alan Walter is a retired professional engineer living in Oxford. He was born in Wales and worked in Halifax. He spends much of his time in Oxford, where he operates a small farm. His column will appear bi-weekly.