There has been Nankai trough mega quakes before , what’s different is this seems to be the first time they understand the fault line well enough to make a prediction and provide warnings about future quakes.
The title makes it sound like this would be the first Nankai trough in quake.
I assume this means a plate is shifting? What about the other side of the plate(s)? Won’t that put more pressure there as well?
> Japan issues first-ever alert over risk of Nankai Trough megaquake
What is "Nankai Trough" ?
I am not an expert and English is not my first language, but isn't a trough a geological structure beneath the earth from which earthquakes can be emitted (a fault line)?
The Nankai Trough is the name for the oceanic trench where the Philippine Sea tectonic plate subducts below the eastern margin of the Eurasian tectonic plate, where southern Japan sits. The interface between the two plates is the subduction fault line that hosts large earthquakes in southern Japan.