Japan's capital is marking the 88th anniversary of a destructive earthquake that killed an estimated 130,000 people and left most of the survivors in Tokyo and Yokohama homeless.
The country was again reminded of its precarious position atop seismic faults in March when a magnitude 9.0 earthquake triggered a massive tsunami, leaving 20,000 people dead or missing. Now Japanese scientists are warning this year's quake may have increased the chances of a huge new tremor underneath Tokyo.
Japan’s government Thursday carried out a simulated response to a Magnitude 7.3 earthquake striking below Tokyo.
It is an annual exercise on the anniversary of the September 1, 1923 quake, which measured 8.2 on the Richter scale and destroyed most of Tokyo and Yokohama.
Outgoing Japanese Prime Minister Naoto Kan addressed the country during the drill news conference.
He was simulating the announcement of the major temblor.
The drill comes less than six months after the devastating quake and tsunami in the Tohoku region, in northeastern Japan.
And, despite Thursday’s drill, 63-year-old Kazunori Kuga in Tokyo says he’s worried.
He says holding the exercise only once a year is inadequate. He feels the country still is largely unprepared..
Scientists are also worried, because they say this year’s huge quake has triggered continuing seismic activity across the country.
In the Tokyo metropolitan area, the number of small earthquakes has increased 500 percent compared to before March 11.
Tokyo is hit by a major tremor, on average, every 200 years. But the seismologists say this year’s magnitude 9.0 quake, less than 250 kilometers from the Japanese capital, has them rethinking that time frame.
Professor Naoshi Hirata is a director at Tokyo University’s Earthquake Research Institute. He notes that until this year’s huge earthquake, the official Japanese government consensus was the Tokyo area had a 70 percent chance of getting struck by a magnitude 7.0 earthquake within 30 years.
"My feeling is the probability has increased. But it's very hard to say how much the percentage increased because there's many factors, many reasons that control the seismic activity," said Hirata. "I cannot say the exact number. But, in general, the probability has increased after the Tohoku earthquake."
Hirata says it is premature to be more specific.
"We're evaluating the probability using the data we got after the March 11th earthquake," he said.
That evaluation is to be completed next March. The new data could compel Japan’s government to issue a new assessment with a greater probability, a higher magnitude, a shorter time frame or some combination of those variables.
Japan is one of the most seismically active countries in the world and Tokyo sits on one of the most earthquake prone parts of the country.