On the Statistical Nature and Dynamics of Seismogenesis in the NW Circum-Pacific Belt: A Study Based on Non-Extensive Statistical Physics

TL;DR

This study analyzes the statistical nature and dynamics of seismic activity along the NW Circum-Pacific Belt using non-extensive statistical physics, revealing differences in correlation and complexity between shallow and deep earthquakes and contrasting behaviors with other regions.

Contribution

It applies non-extensive statistical physics to seismic data to distinguish correlation patterns in shallow versus deep seismicity and links these patterns to geodynamic settings and fault network models.

Findings

Deep seismicity is mostly uncorrelated and quasi-Poissonian.

Shallow seismicity shows weak to moderate long-term correlation.

Distinct behaviors observed compared to California and Alaska regions.

Abstract

We inquire the statistical nature and dynamics of shallow and deep seismogenesis along major plate margins of the NW Circum-Pacific Belt, by examining whether earthquakes are generated by Poisson processes and are independent (uncorrelated), or by Complex processes and are dependent (correlated). Analysis is based of Non Extensive Statistical Physics and the complete and homogeneous catalogue of the Japan Meteorological Agency for the period 2002-2016.5. Emphasis is given to background seismicity recovered by removing aftershocks with stochastic declustering. Long-term correlation and long-range interaction is mostly weak to moderate in shallow background seismicity. Conversely, deep seismicity is mostly uncorrelated (quasi-Poissonian), particularly in Wadati-Benioff zones. As function of time, shallow background seismicity exhibits persistent weak to moderate correlation; sub-crustal background seismicity is generally quasi-Poissonian but may dynamically transition to moderate-significant in association with temporal clusters of large earthquakes. A universal such effect was observed ahead of the 2011.19 Tohoku mega-earthquake. These results contrast observations along the Pacific-North American transformational plate boundaries of California and Alaska which are generally correlated, suggesting that the geodynamic setting is essential in the development of self-organization and Complexity. Moreover, observations appear consistent with simulations of small-world fault networks in which free boundary conditions at the surface allow for Complexity to develop, while fixed boundary conditions at depth do not.