“How do you (or scientists) know that the movement of tectonic plates could not be due to the shifting of a liquid mass underneath it?”
The primary reason is that seismic waves don’t indicate the presence of a large liquid layer beneath the crust. If there were an ocean-like layer under the plates, we would expect clear seismic wave disruptions, but we don’t see this.
“The Buddha did not provide any details, and I will not speculate. But my point is no one knows for sure. Yes. The shifting of tectonic plates could be the “immediate cause” But that could be due to the other reasons. We don’t know enough about the Earth’s core to say for sure.”
That’s a fair perspective but the reason I was concerned was because the sutta’s description sounded quite basic and medieval. There isn’t an evidence that weather conditions can influence earthquakes short term, but in the long term the movement of the oceans could have an impact. I apologize if I sound like a nitpicker but the mind is often curious. Buddha had to adjust his discourses to people of his time who had a very limited understanding of the world and in his own words, he said he only teaches 2 things – suffering and the end of suffering, which perhaps doesn’t include explaining physical details like seismography.
But I would still like to discuss the sutta though. It lists the causes for “great earthquakes”, which doesn’t seem to include small foreshocks. Do we know if the whole planet (or a big portion of it) shakes when one of the listed events occur? I also wonder which one of the 8 causes did Ananda experience that led him to ask the question to Buddha.