This magnetic anomalies have been noticed before an earthquakes on many occasions. For example this study found 2 out of 3 major earthquakes studied had simila

This magnetic anomalies have been noticed before an earthquakes on many occasions. For example this study found 2 out of 3 major earthquakes studied had similar precursor events. https://www.sciencedirect.com/science/article/abs/pii/S1474706504000488 https://www.sciencedirect.com/science/article/abs/pii/S14747... It’s not consistent, but it’s more than a one off correlation.