An extremely deep magnitude 4.9 earthquake has occurred near the original large Japan 8.5M (7.8 magnitude revised) earthquake epicenter.
Measuring at a depth of 428 miles / 690km, this earthquake is one of the deeper earthquakes to occur in the recent past… just a few miles less the original Japan 8.5M event (which itself was very deep).
The area below the Pacific plate, where these earthquakes are occurring, is called the Asthenosphere. A deep layer of semi-melted magma, on which the plates rest atop.
At the start of this year (2015), scientists in New Zealand set out to do new tests / experiments on the Asthenosphere in order to determine the effect of deeper earthquakes on surrounding areas.
The findings determined something we’ve known (via research and reporting) for a fairly long time — deep earthquakes cause shallow larger earthquakes in nearby adjacent areas within days (or less) of the deep event occurring.
The shallow earthquakes are usually 1-2 magnitudes higher than the deep earthquakes, and usually strike at a shallow level to the West / Northwest of the deep epicenter.
Here is the video I made on the subject when the announcements were made in the media regarding the asthenosphere findings:
Information on the 4.9M deep earthquake near Japan from the EMSC. The USGS feed is not live any more (shut off !):
M 4.9 – BONIN ISLANDS, JAPAN REGION – 2015-06-02 21:04:29 UTC
|Region||BONIN ISLANDS, JAPAN REGION|
|Date time||2015-06-02 21:04:29.1 UTC|
|Location||27.88 N ; 140.64 E|
|Distances||844 km S of Yokohama-shi, Japan / pop: 3,574,443 / local time: 06:04:29.1 2015-06-03
816 km S of Shizuoka-shi, Japan / pop: 701,561 / local time: 06:04:29.1 2015-06-03