風知草：首都地震、不安と油断＝山田孝男

(Mainichi Japan) January 30, 2012
Anxiety and inattention over Tokyo's next Big One
風知草：首都地震、不安と油断＝山田孝男

Last week, the possibility of a new political party being formed under the leadership of Tokyo Gov. Shintaro Ishihara emerged, but Tokyoites were more shocked by news indicating there was a 70 percent chance of a magnitude 7-level earthquake hitting the capital within four years.
　先週、首都圏住民をギョッとさせたニュースは増税より石原新党より、「Ｍ（マグニチュード）７級の首都地震、４年以内に７０％」だった。

The news caused a stir because it was based on projections by the authoritative Earthquake Research Institute (ERI) at the University of Tokyo.
　それも天下の東大地震研究所の試算だというので騒ぎになった。

I visited professor Naoshi Hirata, 57, director of the institute's Earthquake Prediction Research Center, thinking the institute's announcement daring.
But I soon learned that this figure was not an "announcement."
思い切った発表をしたものですね、と平田直（なおし）教授（５７）＝地震予知研究センター長＝に聞きに行って初めて知ったが、発表ではなかった。

The episode is very interesting.
このてんまつは興味深い－－。

An initial report on the likelihood of a major quake appeared in The Yomiuri Shimbun's Jan. 23 morning editions. 　初報は読売新聞２３日朝刊だった。

In a front-page exclusive, the daily reported the news with the banner headline: "70% chance of magnitude-7 level Tokyo earthquake within 4 yrs.''
１面で「首都直下型／４年内７０％／Ｍ７級／東大地震研試算」と特報した（東京本社最終版）。

The Nikkei, The Tokyo Shimbun and the Mainichi Shimbun followed suit in their evening editions and The Asahi Shimbun and The Sankei Shimbun caught up with them in their Jan. 24 editions.
日経、東京、毎日が夕刊で追い、朝日と産経は２４日朝刊で伝えた。

All trailing dailies had almost identical headlines.
各紙とも見出しは読売と同じである。

TV stations quickly reported the news through their news departments as well as in other programs. 　テレビは報道部門だけでなく、各局ごとにいくつもある情報番組が一斉に反応した。

Overwhelmed by a barrage of reports by news organizations, the ERI published a special explanation online to account for the reasons behind the Yomiuri report.
オールマスコミの怒とうの攻勢に音を上げた地震研が、ホームページ上に読売報道の背景解説のための特設サイトを立ち上げたというのが実情だった。

Adding a twist to the saga was the fact that the ERI's study team had reported its predictions at an open forum last fall, and they were covered by the mass media.
　しかも、地震研の研究チームのこの見解は昨秋、公開の研究発表会で報告され、報道もされている。

Looking back, the Mainichi Shimbun reported in its Sept. 17, 2011 editions that there was a 98 percent chance of a magnitude 7-level earthquake striking the metropolitan region within 30 years.
そう聞いて毎日新聞の縮刷版にあたると、はたして９月１７日朝刊３面に「首都圏直下／Ｍ７級／３０年で９８％」という記事があった。

According to Hirata, a 98 percent chance within 30 years and a 70 percent chance within four years mean the same thing.
　平田によれば、「３０年以内に９８％」と「４年以内に７０％」は同じである。

But human beings, as they are, take the 30-year span lightly and are surprised by the four-year timeline.
だが、人間、３０年ならまだ先と侮り、４年と聞けば驚く。

The Yomiuri keenly restructured the publicized data and emphasized the period "within four years," causing a big public reaction and forcing other news outlets to follow suit.
読売は公表ずみのデータを鋭角的に再構成し、「４年以内」を強調したことで反響を呼び、他のマスコミも追随せざるを得なかった。

As I was looking into the circumstances surrounding the quake prediction story, the nonfiction book "The Great Kanto Earthquake," by Akira Yoshimura (1927-2006), occurred to me.
　この経緯を調べて思い出したのが吉村昭（１９２７～２００６）のノンフィクション「関東大震災」である。

From the end of the Meiji era to the early Taisho period, Akitsune Imamura, an assistant professor of seismology at Tokyo Imperial University (now the University of Tokyo), predicted a Tokyo earthquake in newspaper and magazine articles.
　明治の末から大正の初めにかけ、東京帝大地震学教室の今村明恒助教授は新聞・雑誌で首都地震を予言した。

But Fusakichi Omori, Japan's foremost authority on seismology and chairman of seismology at the national university, was worried about a commotion in society and tried to defuse public anxiety, resulting in a standoff with Imamura.
一方、日本の地震学の最高権威と仰がれた同教室の大森房吉主任教授は社会の動揺を懸念、火消しに努めて今村と対立した。

On Sept. 1, 1923, the magnitude-7.9 Great Kanto Earthquake devastated Tokyo and its vicinity. Omori lost face and died in frustration, while Imamura was catapulted into fame.
　１９２３（大正１２）年、関東大震災（Ｍ７・９）が発生、面目丸つぶれの大森は失意の中で死に、今村の時代がくる。

But Imamura had sparked confusion when freely talking about earthquakes before eventually toning his warnings down.
今村は求められるまま奔放に発言して混乱が拡大、しだいに寡黙になっていく……。

The balance between earthquake predictions and reporting is delicate.
　地震予知と報道の呼吸は微妙だ。

When I asked Hirata if the latest episode reminded him of the row between Omori and Imamura, he said with a wry smile, "It's not such a big deal."
大森・今村論争を意識したかと聞くと、平田は「そんな大それた話じゃない」と苦笑しつつ、こう言った。

"A magnitude-7 quake's energy is one thousandth of the (magnitude-9) Great East Japan Earthquake.
　「マグニチュード７のエネルギーは東日本大震災（Ｍ９）の１０００分の１ですよ。

We did not predict an inland earthquake in the capital," Hirata says. "
首都直下と予測したわけでもない。

The reports tended to cause misunderstanding but were meaningful in that they sounded an alarm against inattention in the Kanto region.
誤解を招きやすい報道でしたけれども、関東地方の油断に警鐘を鳴らす意義はあった。

The chances of a big earthquake are greater than before and it is necessary to prepare."
大地震の発生確率は前より高まっており、備えは大事です」

At the outset of a news conference on Jan. 27, Tokyo Gov. Ishihara mentioned disaster-prevention steps, believing there would be questions about the University of Tokyo's predictions. However, none of the questions related to the earthquake predictions.
　石原慎太郎・東京都知事は２７日の記者会見の冒頭、「どうせ質問が出るだろう」と先回りして防災を語ったが、質問はゼロ。

His 30-minute news conference solely covered questions about the new political party under consideration.
３０分の会見はすべて石原新党に費やされた。

The shocking reports about a 70 percent chance of an earthquake hitting the metropolitan area within four years didn't appear to make a dent at all at the news conference.
衝撃の「４年以内に７０％」報道とはいえ、その程度のものだった。

News reports are cues for people to become aware of inattention.
　報道は油断に気づくきっかけに過ぎない。

The bottom line is how to react in an emergency situation.
いざという時、どう動くか。

Yoshimura's parents went through the Great Kanto Earthquake.
吉村昭は関東大震災を体験していないが、両親は被災した。

During U.S. air raids on Tokyo in the closing days of World War II, Yoshimura got yelled at by his father when he tried to flee with a pack on his back.
東京大空襲（４５年）でリュックを背負って逃げようとした時、その父に「手ぶらで逃げろ」と怒鳴られた。

Tales by survivors of the March 11 disasters and Yoshimura's books are filled with survival tips that cannot be found by looking to disaster-prevention goods.
　３・１１を生き延びた人々の体験談や吉村の著作には、防災グッズでは得られないものが詰まっている。

(By Takao Yamada, Expert Senior Writer)
毎日新聞　2012年1月30日　東京朝刊