Earthquakes on the USGS list
The USGS table of the 20 largest earthquakes since 1900 includes two events it places near the east coast of Honshu. Both are on this page as published epicenters. They are not a map of the trench.
| Earthquake | Mag | Time (UTC) | Epicenter |
|---|---|---|---|
| 2011 M9.1 Tohoku, Japan | 9.1 | 2011-03-11 05:46 UTC | 38.3, 142.37 |
| 1933 M8.4 Sanriku, Japan | 8.4 | 1933-03-02 17:31 UTC | 39.21, 144.59 |
The 2011 event is the Tohoku earthquake, M9.1, 11 March 2011 at 05:46 UTC, epicenter 38.30°N, 142.37°E. The 1933 event is the Sanriku earthquake, M8.4, 2 March 1933 at 17:31 UTC, epicenter 39.21°N, 144.59°E. This page does not repeat casualty figures.
Volcanoes are not those epicenters
Fujisan is an Izu-arc stratovolcano in the Smithsonian file, with a last-eruption year of 1708. Its latitude puts it in our Japan / Ryukyu rectangle, not in the Izu–Bonin–Mariana rectangle, which stops at 35°N. Aira (the caldera system usually called Sakurajima) is in the Ryukyu arc, with a last-eruption year of 2026 in the snapshot. An active caldera and a trench earthquake can both be “Japan” in a headline and still be different sources.
Rectangle
The Japan / Ryukyu rectangle is latitude 24 to 46 and longitude 128 to 150. The 2011 epicenter at longitude 142.37 is inside it. The 1933 epicenter at longitude 144.59 is also inside it. Being inside the rectangle is a filter on this website. It is not a shake map.