Qualla: 2021 Fukushima Earthquake

2021 Fukushima Earthquake: Introduction

Tue, 17 Feb 2026 00:00:00 GMT

Photo credit SuFlyer, CC0. Ten days before the tenth anniversary of the worst earthquake in modern Japanese history, the same ocean struck again. At 23:07 on Saturday, February 13, 2021, a magnitude 7.3 earthquake ruptured deep within the Pacific plate beneath the seafloor off Fukushima Prefecture. Within minutes, three aftershocks of magnitude 5.3 rattled the region. The Japan Meteorological Agency soon classified the event as yet another aftershock of the 2011 Tohoku megathrust -- a seismic ghost that, a full decade later, was still redistributing stress through the fractured rock of the Japan Trench.

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2021 Fukushima Earthquake: Ground Motion Beyond Measure

Tue, 17 Feb 2026 00:00:00 GMT

Photo credit SuFlyer, CC0. The shaking was extraordinary. At Yamamoto, Miyagi, instruments recorded a peak ground acceleration of 1,432 gals -- exceeding the 980 and 1,362 gals measured at Mashiki during the devastating 2016 Kumamoto earthquakes, which had been assigned the maximum Shindo 7 intensity. The ...

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2021 Fukushima Earthquake: A Coseismic Gap Revealed

Tue, 17 Feb 2026 00:00:00 GMT

Photo credit SuFlyer, CC0. The earthquake's tectonic story reads like a detective novel. Back-projection analysis revealed that the 2021 rupture occurred within a coseismic gap of the 2011 mainshock -- a patch of the subduction zone that had not slipped during the mega-earthquake. The enormous stress trans...

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2021 Fukushima Earthquake: Darkness Across Tohoku

Tue, 17 Feb 2026 00:00:00 GMT

Photo credit SuFlyer, CC0. More than 950,000 homes lost power as multiple power plants went offline across the country. Shinkansen bullet train service on the Tohoku line was reduced to one train per hour between Tokyo and Nasushiobara. The Akita and Yamagata mini-Shinkansen lines were fully suspended, as ...

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2021 Fukushima Earthquake: Temples, Shrines, and Stone Lanterns

Tue, 17 Feb 2026 00:00:00 GMT

Photo credit SC Sendai City, CC BY-SA 4.0. The Zuihoden Temple in Sendai's Aoba ward saw about 100 stone lanterns and tombstones collapse -- echoing the 2011 earthquake, when the same temple lost 200 lanterns and part of its stone wall. At the Inari Shrine in Fukushima City, a stone lantern fragment fell from five meters ...

Image: SC Sendai City | CC BY-SA 4.0

2021 Fukushima Earthquake: Living on the Boundary

Tue, 17 Feb 2026 00:00:00 GMT

Photo credit SuFlyer, CC0. Prime Minister Yoshihide Suga initially reported no deaths -- a statement that proved false when the Fukushima City victim was discovered on February 23. The government set up crisis management operations within two minutes of the earthquake, and 70 evacuation centers opened acro...

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