Evidence for Synchronization in the Global Earthquake Catalog

Abstract

Phase alignment (synchronization) is a generalized property of interacting oscillators. If such interactions apply to earthquakes, they should manifest as time‐dependent variations in earthquake productivity organized according to a characteristic elastic loading period. Defining this period as renewal interval, the time required to accumulate the elastic potential energy released in a rupture, gives a consistent scaling property that can be used to search for temporal organization. We test for the expected structure in earthquake productivity using three different statistical tools optimized for different temporal sensitivities: Schuster spectra for events with short renewal intervals (0–25 years), Fourier power spectra for events with short and intermediate renewal intervals (0–100 years), and topological data analysis (TDA) for events with long renewal intervals (>100 years). All three indicate that earthquakes are organized in time according to renewal interval. Accounting for such unsteady temporal organization may improve forecasting skill by providing time‐dependent event probabilities.

A Comparative Analysis of Four Commonly Implemented Declustering Algorithms

“…Additionally, far eld triggering of seismicity (e.g. Freed, 2005), and evidence for global synchronization of earthquakes (Bendick & Bilham, 2017;Bendick & Mencin, 2020) both cast doubt on the Poisson process hypothesis for large scale systems.…”

Different Fault Response to Stress during the Seismic Cycle

“…Love and Shida numbers) due to its local temperature and geochemistry. These modulations act through two different mechanisms on the outer layers of the Solid Earth: the brittle and outermost part of the crust is elastically affected by tidal waves, which induce a stress variation in rocks that, depending on the local geodynamics, promotes or, on the contrary, can prevent the achievement of the critical breaking point, so that it plays a statistically significant role in fault activation [14][15][16], while solid tides actively modulate plate motion at low frequencies over geological periods [17,18] due to a heterogeneous dissipation of the tidal torque at the LVZ level.…”