Furthermore, Mr Yanagisawa's assumption that banks will not need another injection of public funds in order to survive these massive write-offs may also prove mistaken.

ECONOMIST: Bank reform in Japan

The quakes prompted state officials in January to order four fluid injection wells in the eastern part of the state to be "indefinitely" prohibited from opening.

CNN: Debate over fracking, quakes gets louder

Carbon dioxide can sometimes be sold to oil companies for injection into partially depleted wells, in order to force more petroleum out of them.

ECONOMIST: Carbon capture and storage