A global survey of short term slow slip events and its influence on crustal earthquakes

Kelian Dascher-Cousineau, & Roland Bürgmann

Submitted September 10, 2023, SCEC Contribution #13087, 2023 SCEC Annual Meeting Poster #166

Slow slip events, unfolding over days to years, have been proposed to mediate stress transfer and earthquake nucleation. This study systematically analyzes the relationship between slow slip events and seismicity. We aggregate a comprehensive global geodetic record of slow slip events from Japan, Taiwan, Western North America, Mexico, Costa Rica, and New Zealand. These slow slip events generally have magnitudes equivalent to MW 5.5 or greater and span up-dip and down-dip of the seismogenic zone. To investigate the impact of slow slip events on seismicity, we stack earthquake sequences before, during and after these events. We find that the tendency for elevated seismicity is mild and restricted to the immediate vicinity of the slow slip events. Background seismicity has a gap around impending slow slip events; the gap then features the highest seismicity during slow slip. The resulting trends don't hinge on any one subregion. Our findings place important empirical constraints on the link between slow slip and potentially damaging earthquakes. Are the modest changes in seismicity consistent with the stress changes from the slow slip events? We further investigate and delineate the ramifications of stress- and friction-based explanations for the paucity of seismicity during short-term slow slip earthquakes.

Key Words
Slow slip, Stress, Nucleation, Cascade, Forecasting

Citation
Dascher-Cousineau, K., & Bürgmann, R. (2023, 09). A global survey of short term slow slip events and its influence on crustal earthquakes . Poster Presentation at 2023 SCEC Annual Meeting.

Related Projects & Working Groups
Earthquake Forecasting and Predictability (EFP)