The findings were made using 800 seismic sensors and recording fluctuations underground that can map geological disturbances.
The new method thus enabled the scientists to observe the anomalies caused by the perturbations from the earthquake in volcanic regions under pressure.
Mount Fuji, which exhibits the greatest anomaly, is probably under great pressure, although no eruption has yet followed the Tohoku earthquake.
The last time Mount Fuji erupted was on 16 December 1707, and that eruption was preceded by the violent 8.7-magnitude Hoei earthquake 49 days before.
With regards to the 2011 earthquake on 11 March, it was followed by a 6.4 magnitude quake four days later.
This confirmed the criticial state of Mounti Fuji to the researchers.
They add, however, that there is no need for evacuation or any other drastic measures in Japan yet, although caution must be taken.
‘All we can say is that Mount Fuji is now in a state of pressure, which means it displays a high potential for eruption,’ Dr Brenguier added to the Guardian.
‘The risk is clearly higher.’
The ‘critical’ nature of the volcano comes from the state of the magma stored 3.1 miles (five kilometres) beneath the surface in the rock mass.
‘This part of the crust is kind of critical in a sense that perturbation from seismic waves generated by an earthquake will generate quite significantly in the crust,' Dr Brenguier tells MailOnline.
‘It is critical in fracturation of the rock mass below the volcano.
‘This could eventually lead to transport of magma to the surface.
‘We can say that there is a high risk, there is a zone, an area that we image, that shows an anomaly of pressure.
‘There were theories that the magma should be quite pressurised because the last eruption was 300 years ago.
‘For the first time we made a direct observation of this kind of critical stage.
But he adds it is not possible within their results for the researchers to give an exact timescale for when an eruption might occur.