The government held a drill Monday to prepare for the latest massive earthquake feared to hit within the next 30 years.

The Nankai Trough drill was the first held since a new warning system debuted in November. The hypothetical scenario involved a magnitude 9 quake that strikes after an emergency warning is issued for a magnitude 7 foreshock in the Nankai Trough, a sea trench off central Japan that stretches southwest along the Pacific coast of the Japanese archipelago.

The government's Earthquake Research Committee, chaired by professor Naoshi Hirata of the University of Tokyo, announced on Feb. 9 that the probability of a magnitude 8 or 9 earthquake occurring in the Nankai Trough had risen slightly from last year to 70 to 80 percent within 30 years as of Jan. 1.

Similar claims have been made for other regions of Japan for decades, but Japan has reportedly had little luck predicting major earthquakes despite pouring significant financial resources into prediction research.

Keiichi Ishii, the land minister, and other senior officials participated in the exercise, evaluating measures to gather information, deploy staff and capture drone footage.

In the drill, government agencies reported measures to deploy helicopters on standby after an emergency warning, and to move rescue vehicles from the Sea of Japan coast toward the Pacific coast.

Under the new system, the Meteorological Agency will warn of the heightened risk of a powerful earthquake in areas near the trough after a foreshock or crustal movement is detected.