Figure 7. (a) Coulomb stress transferred to the focal mechanisms of background (before the Dec. 5, 2024, shock) earthquakes. Stress increases on the northern tip of the San Andreas, but almost no thrust mechanisms exist for the Cascadia Fault, so no conclusions can be drawn there. (b) The 2022 magnitude 6.4 Ferndale earthquake promoted earthquakes where the San Andreas enters the Mendocino Triple Junction, but inhibited quakes farther east, onshore. (c) The combined impact of the two quakes appears to promote earthquakes where the San Andreas merges into the Mendocino Fault. Credit: Temblor, CC BY-NC-ND 4.0