Journal of Geography and Cartography 2026, 9(1), 11794; https://doi.org/10.24294/jgc11794

The Fiji–Tonga–Kermadec convergent margin represents one of the most seismically volatile regions globally, defined by complex subduction dynamics and a high density of deep-focus events. This study performs a high-resolution exploratory investigation of a 1000-event seismic catalog to resolve the intricate interplay between rupture magnitude, focal depth, and spatial distribution. Moving beyond baseline descriptive summaries, the study employs Exploratory Spatial Data Analysis (ESDA), including non-parametric 2D kernel density estimation and hexagonal binning, to delineate the latent tectonic architecture of the region. Our analysis identifies a pronounced bimodal depth signature, with focal concentrations in the shallow crust (<100 km) and the transition zone (>500 km). These findings empirically validate the thermal and phase-transformation mechanics of the Wadati–Benioffzone. Multivariate diagnostics further reveal a robust linear dependency 𝑟 = 0.71 between seismic magnitude and the global monitoring footprint, providing a quantitative metric for energy-dependent detectability across the station network. By bridging classical geostatistical workflows with modern spatial intensity modeling, this research provides a reproducible, data-driven foundation for enhancing seismic hazard zoning. These insights are particularly critical for improving infrastructure resilience and disaster risk reduction (DRR) strategies in Small Island Developing States (SIDS) facing cascading tectonic risks.