M6.9 and 5.3 occurred Ogasawara island offshore again / Epicenter depth was 480 km

According to Japan Meteorological Agency, an earthquake of M6.9 happened Ogasawara island offshore again at 21:19 of 6/23/2015 (JST).

(cf, M8.5 occurred Ogasawara island offshore / Seismic intensity 5+ in Greater Tokyo Area [URL])

4 minutes later, M5.3 also occurred at almost the same epicenter.

Both of the quakes had epicenter 440 – 480 km deep underground.

The previous quake in this area also had extremely deep epicenter and it was the deepest for M8 class of the quakes since 1900.

(cf, The epicenter of 5/30 quake was deep as lower mantle of the earth / Deepest for M8 class quakes since 1900 [URL 2])


The maximum seismic intensity was 4. Japan Meteorological Agency has made no announcement on the possible reasons for these extremely deep quakes that have been happening Ogasawara island offshore.







Français :

Séismes M6,9 et 5,3 encore au large de l’île d’Ogasawara : épicentres à 480 km de profondeur


Selon la Japan Meteorological Agency, un séisme M6.9 a encore frappé au large de l’île d’Ogasawara le 23 juin 2015 à  21:19 (JST). (cf. Séisme M8,5 au large des îles Ogasawara / Intensité 5+ dans le Grand Tokyo)

4 minutes après, un M5.3 s’est aussi produit pratiquement au même endroit.
La profondeur des deux épicentre est entre 440 et 480 km.
Le séisme précédent de cette région avait également eu un épicentre extrêmement profond, il était le plus profond séismes de classe M8 depuis 1900. (cf. L’épicentre du séisme du 30 mai était situé dans le manteau profond : le record pour les M8 depuis 1900)

L’intensité sismique maximale a été de 4. La Japan Meteorological Agency n’a émis aucun communiqué expliquant les causes possibles de ces séismes extrêmement profonds qui frappent au large de l’île d’Ogasawara.


About this site

This website updates the latest news about the Fukushima nuclear plant and also archives the past news from 2011. Because it's always updated and added live, articles, categories and the tags are not necessarily fitted in the latest format.
I am the writer of this website. About page remains in 2014. This is because my memory about 311 was clearer than now, 2023, and I think it can have a historical value. Now I'm living in Romania with 3 cats as an independent data scientist.
Actually, nothing has progressed in the plant since 2011. We still don't even know what is going on inside. They must keep cooling the crippled reactors by water, but additionally groundwater keeps flowing into the reactor buildings from the broken parts. This is why highly contaminated water is always produced more than it can circulate. Tepco is planning to officially discharge this water to the Pacific but Tritium is still remaining in it. They dilute this with seawater so that it is legally safe, but scientifically the same amount of radioactive tritium is contained. They say it is safe to discharge, but none of them have drunk it.


June 2015