The recent, and continuing, earthquakes in Kyushu once again have many people consulting maps to determine just where Japan’s fault lines are situated, and whether where they live is more, or less, likely to see a large temblor anytime soon.

In the Kansai region, there are about two dozen major fault lines that lie partially or entirely in the roughly six prefectures — Kyoto, Shiga, Nara, Osaka, Hyogo and Wakayama — that form the traditional heart of the region.

There are also fault lines in Fukui Prefecture, including under areas hosting the nuclear power plants that supply much of the region’s electricity.

The one that has Osaka residents the most concerned is the Uemachi fault, a roughly 42-km fault that runs from Toyonaka in the northern part of Osaka Prefecture down to the center of the city of Osaka before terminating around Kishiwada, not too far from Kansai airport. Seismologists believe there is only a 2 or 3 percent probability of a major earthquake along this fault over the next couple of decades.

Elsewhere, the Mikata and Hanaore fault zones run from Wakasa Bay in Fukui Prefecture — not far from the nuclear plants — down through the city of Kyoto, while the Ikoma fault zone runs along the border between eastern Osaka and Nara Prefecture. The probability of earthquakes occurring along the Mikata and Hanaore fault zones over the next 30 years is judged to be minimal.

So where in Japan can one move to get as far away as possible from seismic fault lines? A glance at official geological maps shows that, on Honshu, Okayama Prefecture has virtually no faults, while most of central and northern Hokkaido is also largely fault-zone free.

Much of southern Wakayama and many places along the Pacific coast are free from fault lines. But the real worry in those places is a major quake in the Nankai Trough area along the ocean floor that could trigger tsunami. Given the official prediction of a 70 percent chance of a massive earthquake striking the Nankai Trough within 30 years, residents along the coastline from Kyushu to the Kanto region have reason to be careful.

In a time of both misinformation and too much information, quality journalism is more crucial than ever.
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