A series of small earthquakes struck near Iwaki, Fukushima, on Saturday, Nov 7, per VolcanoDiscovery. The strongest was a magnitude 3.6 event at 10:48 pm local time.
The same day also saw a magnitude 3.5 quake at 11:32 am, both occurring in the North Pacific Ocean northeast of Iwaki, according to the same source.
Earlier in the week, on Friday, Nov 6, two smaller quakes hit the area—magnitude 2.1 and 2.2—also centered in the North Pacific, VolcanoDiscovery reports.