The powerful earthquake that struck northeastern Japan and caused tsunami in late November may have been caused by a slip in a zone that may be an extension of two known active faults under the seabed off the crippled Fukushima nuclear power plant site, according to a new analysis.

Shinji Toda, a professor at Tohoku University who compiled the analysis with a colleague, warned that the suspected extension of the two faults could cause an earthquake in the future and trigger tsunami if blocks of the seafloor shift vertically along either fault.

The geology experts are calling on the Nuclear Regulation Authority to conduct an emergency probe into the faults and the suspected extension. They will report their findings to a meeting of the government's earthquake investigation committee on Friday.