Optimizing Earthquake Nowcasting With Machine Learning: The Role of Strain Hardening in the Earthquake Cycle

Abstract

Recent research has developed the idea of earthquake nowcasting, which uses state ("proxy") variables to infer the current state of the earthquake cycle (

Does the Catalog of California Earthquakes, With Aftershocks Included, Contain Information About Future Large Earthquakes?

“…To calculate the EMA N ‐value, and the contribution of the mean number $$\mu (t)$$ of small earthquakes, we construct the temporal ROC for a forward time window $${T}_{W}=$$ 3 years beyond a given time t (Rundle et al., 2022). We note that other researchers are also using ROC methods in earthquake cluster analysis (Ben‐Zion & Zaliapin, 2020; Zaliapin & Ben‐Zion, 2022), similar in some ways to ideas in Rundle and Donnellan (2020) and, Rundle, Donnellan, et al.…”

“…As discussed in Rundle et al. (2022), we find the optimal values of N for the EMA, and the contribution of the mean earthquake μ ( t ) adjustment λ , by maximizing the skill which is the key component of the method of Rundle et al. (2022).…”

“…(2022), we find the optimal values of N for the EMA, and the contribution of the mean earthquake μ ( t ) adjustment λ , by maximizing the skill which is the key component of the method of Rundle et al. (2022). This is indicated in Figures 1d and 1e as a feedback between the state variable curve and the ROC skill calculation.…”

“…Data for this paper was downloaded from the USGS earthquake catalog for California, and are available there. Python code at (https://doi.org/10.5281/zenodo.7186635) can be used to download and model these data for analysis using the methods of Rundle et al (2022). Data.…”

“…To calculate the EMA N-value, and the contribution of the mean number 𝐴𝐴 𝐴𝐴(𝑡𝑡) of small earthquakes, we construct the temporal ROC for a forward time window 𝐴𝐴 𝐴𝐴𝑊𝑊 = 3 years beyond a given time t (Rundle et al, 2022). We note that other researchers are also using ROC methods in earthquake cluster analysis (Ben-Zion & Zaliapin, 2020; The ROC curve (https://en.wikipedia.org/wiki/Receiver_operating_characteristic (accessed 7/20/2022)) is constructed by establishing a series of increasing thresholds T H in the state variable 𝐴𝐴 Θ(𝑡𝑡) from low values to high values.…”