The magnitude-9.0 earthquake on March 11 was the largest recorded in Japanese history, and triggered a massive tsunami that killed about 22,000 people.
Japan’s meteorological agency told the ABC that it has logged nearly 4,000 quakes in the region hit by the tsunami, including tremors greater than magnitude 7.0.
Seismologists have warned Japan is likely to be rocked by aftershocks for months to come.