At https://wattsupwiththat.com/2022/04/16/seafloor-spreading-has-been-slowing-down/ … which pertains to a research paper published by the American Geophysical Union. Sluggish rates of seafloor spreading ‘could‘ mean a drop in greenhouse gas from volcanoes has caused the dip. They could think of nothing else to explain the apparent anomaly. Basically, they are saying that over the last 19 million years seafloor spreading rates have slowed down. Geologists are wondering why? Or rather, a group of geologists who authored the paper are wondering if it has anything to do with greenhouse gas emissions. The comments are worth browsing as some of them have alternative reasons to explain the slow down while others are more sceptical. One wonders at the faith the authors have in the geochronological time frame. Did 19 million years really elapse? It could have been less. It could have been more. Does it really matter? They are numbers. It is the geological column that working geologists use, and the numbers are just that. Numbers. Why take them literally. Well, in this case it was to make mischief by suggesting greenhouse gases play a role in plate tectonics and seafloor spreading. I prefer to muse upon the other suggestions by the commenting public. However, the general assumption was that seafloor spreading was a gradual process, a thoroughly uniformitarian predicament. If seafloor spreading accelerated during major catastrophic events it would stand to reason it would slow or come to a standstill in non-catastrophic periods. It might be as simple as that. However, the idea that the earth is gradually and uniformly cooling at a given rate, rather than an average rate, seems to be accepted. The consensus of comments is that the heat was declining. Will geothermal heat pumps cause the earth to cool faster, one asks. Or is the moon? It is moving away from the earth, at a very small rate of knots. Does that mean there is less stress tectonically on the earth? and therefore less seafloor spreading. What about the Pleistocene? When the Ice Ages were accepted mainstream inserted the Pleistocene era in the geological column, rather than accommodate it within earlier periods. They showed little evidence of long episodes of ice locking up the northern hemisphere and therefore it was deemed necessary to accommodate the Ice Ages in its own geological period, the Pleistocene. Did that create an illusion of a change in the rate of seafloor spreading? If the Pleistocene, or a goodly proportion of it is deleted, does that make seafloor spreading uniformitarian once again? Was there really umpteen Ice Ages during a 3 million year period? Originally, there were only four of them.