Tokyo-centered Earthquake Could Kill 23,000

earthquakes infographic

Skeptikai has had many articles on what I expect will be what everyone has been calling “The Big One” for years. That is, a catastrophic earthquake in the most densely populated city in the world – Tokyo. I never look forward to writing about the potential damage from such an event, but it’s important to keep up with the latest research, and there have been more predictions by the experts in recent months.

A panel of experts spoke last month about this. From Asahi:

A massive magnitude-7 earthquake, expected to strike beneath Tokyo with a high probability within 30 years, could claim up to 23,000 lives, destroy more than 600,000 buildings and cause an estimated 95 trillion yen ($910 billion) loss to the economy, a government panel said Dec. 19.

Using the estimates, the government plans to work out a basic disaster management plan, including emergency response and measures to back up the operations of government ministries and agencies, before the current fiscal year ends in March.

[. . .] The Dec. 19 report said the worst-case scenario would result in 70,000 deaths, including 11,000 from tsunami, and 1.33 million buildings destroyed. That is in addition to 160 trillion yen in economic damages, comprising 90 trillion yen in direct impact and 70 trillion yen in indirect impact.

But there are critics of the panel’s estimates. Unfortunately, it’s not that they think the experts are fear-mongering. Rather, the opposite. They think they are being too conservative in their estimates.

In August 2012 and March 2013, the government released damage estimates for a giant earthquake along the Nankai Trough, a depression on the seabed that extends from Suruga Bay off Shizuoka Prefecture to areas east of Kyushu. Those reports assumed a magnitude-9.1 event that could occur only once in 1,000 years.

The latest report, by contrast, mostly assumed a magnitude-7 class earthquake, which has a 70-percent likelihood of striking beneath Tokyo within 30 years, and is much more common. Consequently, it predicted only limited impact on the operations of central government ministries and financial districts.

“We focused on measures against events that are likely to occur in the near future,” disaster management minister Keiji Furuya told a news conference on Dec. 19. “I hope you understand why we did not do quite the same thing as when we estimated damage from (a giant quake) along the Nankai Trough.”

Yoshiaki Kawata, head of a government panel that produced the Nankai Trough damage estimates, remained unconvinced.

“A lesson from the Great East Japan Earthquake was that there should be no ‘unforeseeable’ event,” said Kawata, a professor of disaster management at Kansai University. “That lesson has not been heeded. The report presupposes that most of the capital’s core functions would survive, which is part of the ‘foreseeable’ damage in the event of a major earthquake.”

One member on the panel that worked out the latest damage estimates defended the report.

“I doubt there is a need to evaluate an even greater ‘unforeseeable’ event hitting beneath Tokyo, which runs the risk of scaring off foreign firms,” the panel member said. “The Nankai Trough is a different story. The most important thing is for the people to envision the damage in their minds on the basis of our estimates and to understand how it can impact them.”

Such an event would also bring down the Tokyo power supply to half of what it is now, which would be extremely detrimental, especially depending on what time of the year it occurs. If it’s at a very cold or very hot time of the year, it will definitely result in a greater number of deaths. I still remember the blackouts we experienced 3 years ago like it was just yesterday. It was not a good experience; and that was in March, which isn’t even as cold as it gets. The Japan Times had this to say:

The tremors will force the capital’s thermal power plants to be suspended in rapid succession, depriving some 12.2 million Tepco customers of power, according to the Central Disaster Management Council.

As a result, troubled Tepco’s capacity is expected to fall to about half of what it needs in the summertime, when demand usually peaks at over 50 million kw, even if electricity procured from other utilities is included.

This brings up the problem of Japan’s quirky bipolar transmission frequencies. Since the electricity frequency is 50 hertz in eastern Japan and 60 hertz in the west, only 1.2 million kw can be transferred between the two regions. That’s enough to be generated by a single nuclear reactor.

A plan is under way to boost the conversion capacity to 2.1 million kw by fiscal 2020, but cross-region transfers will only have a limited effect in alleviating power shortages in Tokyo.

Failure to quickly repair damaged or shut-down thermal plants will force the capital to resort to the same rolling blackouts put into use after the March 2011 Great East Japan Earthquake disrupted power supply in Tokyo.

So it looks relatively inevitable. We’ll have to enjoy the dark for a bit. I just hope we don’t have to worry about the cold or the sweltering heat at the same time.

On the bright side, I haven’t heard anyone talking about the prediction of a 90% chance of a massive Tokyo earthquake in Tokyo by 2016, which may mean we have more time to prepare. On the other hand, the prediction of 10,000 deaths has more than doubled. So we can only hope that by the time it comes, we’re more ready than ever.

 

Photo Credit: Reuters
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