Can slip heterogeneity be linked to earthquake recurrence?

Abstract

The rupture process of two M4 repeating earthquake sequences in eastern Taiwan with contrasting recurrence behavior is investigated to demonstrate a link between slip heterogeneity and earthquake recurrence. The M3.6–3.8 quasiperiodic repeating earthquakes characterized by 3 years recurrence interval reveal overlapped slip concentrations. Inferred slip distribution for each event illustrates two asperities with peak slip of 47.7 cm and peak stress drop of 151.1 MPa. Under the influence of nearby M6.9 event, the M4.3–4.8 repeating earthquakes separated only by 6–87 min, however, reveal an aperiodic manner. There is a distinct rupture characteristic without overlap in the slip areas, suggesting that shortening of the recurrence interval by the nearby large earthquake may change the slip heterogeneity in a repeatedly ruptured asperity. We conclude that the inherent heterogeneity of stress and strength could influence the distribution of coseismic slip, which is strongly tied to the recurrence behavior.

Probing the Variation in Aseismic Slip Behavior Around an Active Suture Zone: Observations of Repeating Earthquakes in Eastern Taiwan

“…This indicates that the peak stress drop inferred using equation 5 is close to the finite source result. Such observation was also seen in M2 RES at Parkfield, indicating that the strong stress heterogeneity may be generally true over a range of magnitude from M2 in Dreger et al (2007) to M4 in Chen et al (2016).…”

“…The dashed line indicates the regression line from central SAF data by Nadeau and Johnson (1998). The box indicates a range of peak and averaged stress drop for two repeating events (M L 4.3 and M L 4.8) by Chen et al (2016).…”

Microseismicity Simulated on Asperity‐Like Fault Patches: On Scaling of Seismic Moment With Duration and Seismological Estimates of Stress Drops

“…Our stress drop results reveal that the standard seismological analyses may systematically underestimate stress drops for small events with more complex rupture shapes, which could be quite common on heterogeneous faults (Chen et al, 2016;Dreger et al, 2007;Wald & Heaton, 1994). Any small event occurring along a stretch of stress concentration or lower friction resistance would have the shape of that feature.…”

“…That shape is ring‐like in our model but may have other geometry, for example, following the (potentially curved) boundary of the stress concentration of the previously arrested larger event or of the creeping‐locked transition, or following a patchwork of favorable stress due to complex prior slip or heterogeneous strength, as in our model. The microseismic sources are indeed observed to be irregular and complex (Chen et al, ; Dreger et al, ), unlike the traditional circular source models with uniform stress drops and elliptical slip profiles codified in the standard seismological methods (e.g., Madariaga, ; Sato & Hirasawa, ). For such more complex sources, the rupture area would not be directly related to the source duration and could in fact be much smaller, as illustrated by our simulations.…”

Revisiting Slow Slip Events Occurrence in Boso Peninsula, Japan, Combining GPS Data and Repeating Earthquakes Analysis

“…Several studies have shown that the magnitude of REs that are located on the same asperity can vary with time in Japan where the Kamishi sequence presents an increase of magnitude from 4.7 to 5.9 after the Tohoku earthquake (Uchida et al, ) and in Taiwan where the sequence of REs has a magnitude of 3.9 and 4.8 after a M 6.9 nearby event (Chen et al, ). Thus, in this study, we do not impose any criterion on magnitude for grouping earthquakes into RE sequences.…”