Background:
Japan's complex tectonic setting produces intense seismicity, yet reliable earthquake prediction remains unresolved. Recent data-driven approaches suggest that classical models may be insufficient, highlighting the value of exploratory analysis of seismic parameters. The Noto Peninsula, despite its distance from major plate boundaries, exhibits persistent shallow seismicity and recent large events, making it a critical region for investigating potential precursory signals and improving forecasting methods.

Objectives:
This study aims to identify seismic anomalies in the Noto Peninsula that may act as precursors to large earthquakes, and to evaluate whether persistent elevation of the magnitude locator provides a more reliable forecasting indicator than scale variations.

Methods:
Earthquake data from the Japan Meteorological Agency catalogue (2007–2026) were analysed using an exploratory data analysis framework. Magnitudes were modelled as normally distributed, with location (μ) and scale (σ) parameters estimated via maximum likelihood. Spatial patterns were examined using a 1° latitude–longitude grid, with monthly aggregation of raw event counts and no smoothing applied. All recorded events, including low-magnitude earthquakes, were retained despite known detection limits. Statistical tools included Q–Q plots, regression, and distribution fitting to identify anomalies. Analyses were conducted in R, with full code publicly available to ensure reproducibility and transparency of the methodology.

Results:
Aftershock decay following the May 2023 earthquake showed two distinct phases inconsistent with classical Omori-type behaviour, while magnitude parameters exhibited atypical patterns, including a delayed and persistent increase in the locator. Spatial analysis revealed increasing seismicity near the Noto Peninsula since 2020, culminating in the January 2024 M7.6 event and rapid offshore propagation. Seismicity remained predominantly shallow, indicating stress accumulation in a near-surface zone rather than along the main plate boundary. Offshore regions displayed high locator and low scale values, resembling volcanic-type seismicity. Additional evidence suggests the presence of shallow seismic bands and possible structural links between Noto and adjacent regions. Post-2024 activity shows partial stabilization but continued complexity.

Conclusion:
Seismic activity in the Noto Peninsula exhibits distinct spatial and temporal patterns, with locator variations providing useful indicators of large events. Offshore anomalies and shallow seismic zones suggest complex tectonic or volcanic influences, highlighting the need for continued monitoring and data-driven forecasting approaches.