Figure 4. The intense swarm beginning in December 2020 is remarkable. The earthquake frequency of magnitude greater than 1.0 shocks increased by about 400-fold, and so the probability of large shocks most likely also increased by the same factor. Note that the March 2007 magnitude 6.7 Noto-Hanto quake, far west of this area, did not increase the seismicity rate in the future 2024 epicentral site, and did not initiate a swarm. Credit: Toda and Stein, 2024