6.9-Magnitude Earthquake Disrupts Japanese Aviation

A magnitude 6.9 earthquake struck northeastern Japan on Saturday at 18:09, disrupting aviation and causing a tsunami advisory for the Miyagi Prefecture. The quake struck at a depth of 59 kilometers and was felt 300 kilometers away in Tokyo, where it registered 3.0 on the Richter scale. As a precaution, 6,911 residents of the town of Watari were evacuated. The tsunami warning for the area was lifted at 19:30, with people advised to stay away from the waterfront.

An All Nippon Airways (ANA) Boeing 737-800 landing at Tokyo
Aircraft traveling to Sendai Airport (SDJ) were forced to divert to other airports. Getty Images.

The Tohoku Shinkansen and other rail lines suspended service until 22:00 while aircraft on route to Sendai Airport (SDJ) were diverted to the following airports as a safety precaution:

  • ANA flight number NH737 from Osaka Kansai International Airport (KIX) diverted to Tokyo Haneda Airport (HND)
  • Skymark Airlines flight number BC156 from Kobe Airport (UKB) did a U-turn and returned to Kobe
  • Peach flight MM422 from Naha Airport (OKA) on the island of Okinawa diverted to  Niigata Airport (KIJ) on the Sea of Japan


2011 Great East Japan Earthquake

As a stark reminder and the reason why Japanese authorities always take seismic events seriously, today’s quake comes days after the 10th anniversary of the magnitude 9.0 earthquake and tsunami that killed over 15,000 people. For many people, it brought back chilling memories of the 2011 Great East Japan Earthquake, with The Japan Times quoting a report from Japan’s public broadcaster NHK.

“I recalled that day 10 years ago,” a man in Ishinomaki city told NHK as he fled to a park on a hill. “Because of our experience of that day, I moved quickly. My heart is pounding hard,” he said.

“It was really bad, long shaking from side-to-side. It was even longer than the quake last month, but at least the building here is all right,” Shizue Onodera told the broadcaster from the shop where she works in Ishinomaki.

“Lots of bottles smashed on the floor,” she said. “The electricity is on.”

Others compared it to a strong quake felt just last month after a quake of a similar scale hit the region.

“Suddenly, the large tremor continued for about 20 seconds,” the broadcaster quoted a disaster official in Iwanuma, Miyagi Prefecture, as saying.

“The shaking caused things on a desk to move, but they didn’t fall, and I felt the shaking was smaller than last month’s earthquake.”

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In 2011 Sendai Airport flooded

When the earthquake struck in 2011, Sendai Airport was damaged by the quake while floodwaters from the Tsunami reached the second level of the passenger terminal. Operations at the airport immediately ceased while 1,300 passengers waited two days to be rescued.

Peach A320
A Peach A320 diverted to Niigata Airport (KIJ). Photo: Getty Images

The airport eventually reopened on April 13 with Japan Airlines and ANA conducting flights to Tokyo and Osaka.

Why does Japan have so many earthquakes?

Japan is located on three tectonic plates referred to as the “Ring of Fire,” an arc of intense seismic and volcanic activity that stretches 24,000 miles (40,000 kilometers) across the Pacific basin. While people in Japan are used to earthquakes and live in buildings built to combat them, there is always the fear of how powerful the next one will be.

90:% of the world’s earthquakes occur along the “Ring of Fire.” Image: Gringer via Wikimedia

The 2011 earthquake and tsunami, which also caused the Fukushima Daiichi nuclear disaster, was the largest ever recorded earthquake in Japan and the fourth strongest in the world after the following:

  • 1960 Valdivia earthquake in Chile
  • 1964 Alaska earthquake
  • 2004 Sumatra earthquake in Indonesia

It should be pointed out that some earlier earthquakes may have been as strong or stronger but were not measured before the development and deployment of seismographs in the early 1900s.

Given what happened to Sendai Airport in 2011, it’s not surprising that planes en route decided to divert or return to other airports.

If you were on one of the diverted flights, please tell us what happened in the comments.