2023/04/17 by Xu, Shiqing
#FOS: Physical sciences #Geophysics (physics.geo-ph) #Soft Condensed Matter (cond-mat.soft)
paper · doi:10.48550/arxiv.2304.08016
Stress drop Δτ and rupture speed Vr are two important earthquake source parameters that control the characteristics of rupture process and the associated ground motion. However, how the two parameters correlate with one another is not fully clear and sometimes can be controversial. Here I propose using the energy balance relation derived from fracture mechanics to understand the correlation between Δτ and Vr. The central idea is to explore the balance between fracture energy Gc and dynamic energy release rate Gd (which itself is a function of Δτ and Vr) under various conditions of Gc. Using averaged values of Δτ and Vr for comparison, it is shown that near constant Gc can yield a positive correlation between Δτ and Vr, whereas variable Gc dependent on space, time or other factors may cause a negative correlation between Δτ and Vr. These results suggest a need to examine the condition of other factors (such as Gc) when evaluating the correlation between Δτ and Vr. Extra issues can complicate the evaluation of the correlation between Δτ and Vr when rupture process is inferred from far-field observations, accompanied by strong spatiotemporal variation, or followed by additional phases, which should be investigated by future studies.