preliminary magnitude
先生、こちらでは午後８時４４分ごろに震度４地震がありました。結構、長く怖い感じの揺れでした。そちらはどうでしたか。
M5.4 quake jolts Chiba Prefecture, vicinity
An earthquake with a preliminary magnitude of 5.4 jolted Chiba Prefecture and its vicinity in eastern Japan including Tokyo on Saturday evening, the Japan Meteorological Agency said.
No tsunami warning was issued and no abnormalities have been reported at nuclear power plants in the country.
The focus of the 8:44 p.m. quake was around 90 kilometers underground in the northwestern part of Chiba Prefecture, the Japan Meteorological Agency said.
http://english.kyodonews.jp/news/2013/11/256868.html
preliminary magnitudeは気象庁の観測結果がまだ完全ではなく、最初のデータをもとにしたものという意味で、「マグネチュードは推定〜」という言い方の日本語に相当します。
