Qualla: April 2011 Miyagi Earthquake

April 2011 Miyagi Earthquake: Introduction

Tue, 17 Feb 2026 00:00:00 GMT

Photo credit Mikenorton, CC BY-SA 3.0. At 23:32 local time on Thursday, April 7, 2011, the seafloor off Miyagi Prefecture lurched again. Less than four weeks after the magnitude 9.0 Tohoku earthquake and tsunami killed nearly 20,000 people, a magnitude 7.1 thrust quake struck 66 kilometers east of Sendai at a depth of 49 kilometers. In most circumstances, a 7.1 earthquake commands global headlines on its own. This one barely registered beyond Japan. The March 11 disaster had been so overwhelming -- an entire coastline erased, a nuclear meltdown underway at Fukushima -- that a "mere" 7.1 aftershock felt almost routine. But for the millions of people in northeastern Honshu who had just begun picking through the rubble of their lives, there was nothing routine about the lights going out again.

Image: Mikenorton | CC BY-SA 3.0

April 2011 Miyagi Earthquake: The Ground That Would Not Stop Moving

Tue, 17 Feb 2026 00:00:00 GMT

Photo credit Mikenorton, CC BY-SA 3.0. The April 7 quake was the product of thrust faulting along the subduction zone where the Pacific Plate dives beneath the North American Plate -- the same boundary that had unleashed the March 11 megathrust. By April 7, the aftershock sequence from that main event already included...

Image: Mikenorton | CC BY-SA 3.0

April 2011 Miyagi Earthquake: Darkness Falls Again

Tue, 17 Feb 2026 00:00:00 GMT

Photo credit Mikenorton, CC BY-SA 3.0. The most widespread impact was the power failure. Some 3.6 million households across several prefectures lost electricity, and by the following day many still sat in the dark. The outage cascaded through critical infrastructure. At the Onagawa Nuclear Power Plant, two of three po...

Image: Mikenorton | CC BY-SA 3.0

April 2011 Miyagi Earthquake: Four Lives Lost

Tue, 17 Feb 2026 00:00:00 GMT

Photo credit Mikenorton, CC BY-SA 3.0. The earthquake killed four people and injured 141. Among the dead was an elderly woman in Yamagata Prefecture whose medical ventilator failed when the power cut out -- a reminder that modern disasters do not always kill through dramatic force. Falling objects, shattered glass, an...

Image: Mikenorton | CC BY-SA 3.0

April 2011 Miyagi Earthquake: Aftershock of an Aftershock

Tue, 17 Feb 2026 00:00:00 GMT

Photo credit Mikenorton, CC BY-SA 3.0. The tsunami warnings were canceled within 90 minutes. The Nikkei stock index dropped sharply at the close of trading but rebounded the following day when the scale of damage proved limited. Life, such as it was in post-disaster Tohoku, resumed. But the psychological toll was hard...

Image: Mikenorton | CC BY-SA 3.0