富士山５合目登山口有裂痕

Recently the NHK News on-line reported the following:

富士山の５合目の登山口の近くに、去年３月の震災後の地震のあと、３０メートル以上にわたって亀裂が入っていたことが分かりました。専門家は火山活動との関連性はないとみていますが、大規模な土砂災害につながるおそれがないか調べる必要があると指摘し、山梨県が調査に乗り出しました。

この亀裂は、山梨県の富士山の５合目の登山口に近い県有地で見つかりました。
長さは３０メートル以上、幅は５センチから８センチほどあり、小さな段差も確認されました。
近くの冨士山小御嶽神社の宮司によりますと、亀裂は東日本大震災の４日後の去年３月１５日、静岡県東部を震源とするマグニチュード６．４の地震が起きたあと見つかり、その後、しだいに埋もれて去年の夏ごろにははっきり見えなくなったということです。
富士山に詳しく、当時亀裂を確認した山梨県環境科学研究所の荒牧重雄所長は「地震の揺れでできた可能性が考えられる。亀裂の１０メートルほど先は崖になっていて、今後の地震などで大規模な土砂崩れが起きるおそれがないか、調査する必要がある」と指摘しています。
山梨県は、専門家の指摘を受けて先月から現場で測量を始め、周辺に亀裂が広がったり地滑りが起きたりする兆候がないか、本格的に調査を始めました。
亀裂からおよそ５０メートル離れた場所には、富士山の５合目の駐車場やレストハウスもあり、この付近はかつて盛り土などで造成された可能性もあるため、当時の経緯も調べることにしています。
(試譯文)

It was understood that near the trail head of Mt. Fuji fifth stage, after the shaking of the earth  due to the earthquake disaster occurred in March last year, a crack of no less than 30 meters had existed. Although the specialists concluded that there was no connection with any volcanic activity, it indicated that it was necessary to investigate whether there was any possibility of leading to a catastrophic earth-and-sand disaster, and Yamanashi Prefecture was to mount an investigation.

This crack was found in the prefecture land near the trail head of the fifth stage of Mt. Fuji in Yamanashi Prefecture.

The length was no less than 30 meters and the width was from 5 cm to 8 cm, and a small level difference was also confirmed.

According to the Shinto priest of the nearby Fuji Shan Small Ontake Shrine, it was said that the crack was found four days after the East Japan great earthquake that occurred on March 15 last year and had a magnitude of 6.4 on the Richter scale, with eastern Shizuoka being the source of the earthquake. The crack was buried gradually and could not be seen clearly afterwards around the summer of last year.

Director Shigeo Aramaki of the Yamanashi Institute of Environmental Sciences which was knowledgeable about Mt. Fuji and had checked the crack in those days pointed out that "it is consider that there is a possibility that it was because of the shaking of the earthquake. The location 10 meters from the crack becomes a cliff, and whether a large-scale mudslide may occur in a future earthquake etc. may need investigation".

Yamanashi Prefecture in response to a specialist's indication began the survey at the spot since last month, a formal investigation had begun to see whether there were signs to show that the crack spread to the outskirts, or a landslide took place,

Since about 50 meters away from the crack it was the location of the Mt. Fuji fifth stage parking lot and a rest house, and there was a possibility to set up an embankment etc. in the vicinity, it was decided that the circumstances of those days would be investigated.

Although a crack has been found, it seems that it is still safe to climb the Mt. Fuji.