Stress and strain comparison: methods, results and applicability

This contribution explores the approach and results of crustal stress and strain rate comparisons across various geological contexts. Since the early 1980s, researchers have investigated the broad applicability of these comparisons in regions with high, intermediate and low deformation rates. The primary data sources for these studies include focal mechanisms and velocity fields from GNSS stations, although additional datasets, such as geological structural data, are also utilized. The stress field is obtained through formal stress inversion, while the strain rate is derived from optimal interpolation of GNSS velocities. The results are compared in terms of stress and strain axes to understand the relationship between them. The increasing number of seismic and geodetic stations over the years has significantly enhanced data quality and coverage, further improving the validity and reliability of this approach. The multidisciplinary nature of this approach underscores its versatility. In seismotectonics, it has proven valuable for detailed kinematic characterizations of plate boundaries (Stephan et al., 2023) and faults (Zoback and Zoback, 1980). In seismic hazard assessment, it aids in identifying areas with relatively high strain rates but low seismic activity, suggesting the discussion of potential seismic gaps (Chang et al., 2003). In geodynamics, the approach enhances our understanding of the deformation forces driving earthquakes (Palano et al., 2013; Pietrolungo et al., 2024). Furthermore, it has significantly contributed to fault mechanics by providing insights into how crustal segments respond to stress loading (Bird et al., 2006). In volcanic contexts, the approach has been particularly effective in elucidating the interplay between tectonic stress and magmatic processes (Keiding et al., 2009). These findings highlight the need to distinguish between short-term deformation from episodic events and long-term tectonic forces to better understand complex geological dynamics (Townend and Zoback, 2006). Drawing from an extensive body of literature, this review offers insights into the challenges and opportunities of applying digital technology to stress and strain comparisons. It summarizes key findings, evaluates their potential, and critically discusses their limitations, providing a nuanced perspective on the approach’s applications and future directions.