A group of experts commissioned by the government warned that more strong earthquakes accompanied by tsunamis may hit the Noto Peninsula area, where a magnitude 7.6 quake struck on Jan. 1 this year.

A magnitude 6.6 earthquake that occurred off the west coast of the peninsula on Nov. 26 was the second-largest quake to hit the area since December 2020, when seismic activity became more frequent, Naoshi Hirata, chairperson of the Earthquake Research Committee, said at a news conference on Tuesday.

Hirata said that he had "never experienced" a situation in which seismic activities are active for four years or longer and an earthquake with a magnitude of 6 or higher takes place nearly every six months.

Seismic activities in the area turned active apparently because upwelling of deep-seated fluid caused small faults to move easily. Meanwhile, the Jan. 1 earthquake was caused by long and large faults, leaving the seismic activity area spreading over some 150 kilometers.

A fault exists near where the November earthquake occurred, according to a map released by the committee in August. There has been no data showing that the fault moved, Hirata said. But he added that unidentified faults may have moved.

The Jan. 1 earthquake brought large-scale changes in the earth crust, making it difficult to detect fluid upwelling.

"It's impossible to say when the series of seismic activities will end," Hirata said. "Earthquakes with a magnitude of 6 or higher may happen intermittently for months or years."