Evidence for rainfall-triggered earthquake activity

• Published in: Geophysical research letters Vol. 33; no. 19; pp. L19303 - n/a
• Main Authors: Hainzl, S., Kraft, T., Wassermann, J., Igel, H., Schmedes, E.
• Format: Journal Article
• Language: English
• Published: Washington, DC American Geophysical Union 01.10.2006; Blackwell Publishing Ltd
• Subjects: Earth sciences; Earth, ocean, space; Earthquake dynamics; Earthquake interaction, forecasting, and prediction; Earthquake source observations; Exact sciences and technology; Role of fluids; Seismicity and tectonics; Seismology; Structural Geology; Central Europe; Germany; Critical state; rainfall; atmospheric precipitation; strength; Europe; rain water; earthquakes; faults; friction; crust; rupture; depth; pore pressure; seismicity
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2006GL027642

Fluids are known to be of major importance for the earthquake generation because pore pressure variations alter the strength of faults. Thus they can initiate earthquakes if the crust is close enough to its critical state. Based on the observations of the isolated seismicity below the densely monitored Mt. Hochstaufen, SE Germany, we are now able to demonstrate that the crust can be so close‐to‐failure that even tiny pressure variations associated with precipitation can trigger earthquakes in a few kilometer depth. We find that the recorded seismicity is highly correlated with the calculated spatiotemporal pore pressure changes due to diffusing rain water and in good agreement with the response of faults described by the rate‐state friction law.