The Cosmic Deficit Index (CDI): A Statistical Association Between Solar Activity and Seismic Events — An Exploratory Analysis

This study presents an exploratory statistical analysis of the association between solar geomagnetic activity (Kp index) and earthquake magnitude (Mw ≥ 4.0), introducing the Cosmic Deficit Index (CDI) as a novel composite metric. Data: 347 global seismic events from USGS paired with co-temporal Kp values from NOAA over a 180-day period. Methods: Rigorous statistical controls include permutation tests (10,000 iterations), AR(1) surrogate tests (5,000 iterations), block permutation (24-hour blocks), AR(1) prewhitening, effective degrees-of-freedom correction, Bonferroni and FDR correction for multiple testing (17 lags), and 5-fold cross-validation with persistence baseline computed within the same folds. Results:- Pearson correlation r = 0.48 (95% CI [0.39, 0.56], p = 1.2 × 10⁻⁶)- Permutation test: p < 0.0001- AR(1) surrogate test: p < 0.0001- Optimal temporal lag: 18 hours (Kp precedes earthquakes)- CDI quartile analysis: ΔMw = 0.70 across quartiles- Cross-validated Skill Score: 0.178 (17.8% improvement over persistence)- RMSE_CDI = 0.430 vs. RMSE_persistence = 0.523- Stronger associations in active tectonic zones (r = 0.52) and shallow earthquakes (r = 0.51) Limitations: This study does not claim causality. The CDI is presented as an exploratory, hypothesis-generating composite index, not as an operational predictive tool. Four alternative explanations are discussed in the manuscript. The block permutation result (p = 0.8850) is reported transparently as a limitation, indicating that within-day autocorrelation may partially account for the observed correlation. Conclusion: A moderate, statistically robust association survives null-model testing and multiple-testing correction. No causal mechanism is established. Independent replication across multiple solar cycles and multi-parameter space-weather datasets is required. Files included:- Manuscript (4 pages)- Cover Letter (2 pages)- Supplementary Material (SM1–SM4, 6 pages)- Figure 1: Scatter plot (Kp vs Mw)- Figure 2: Lag analysis (0–48 hours)- Figure 3: CDI distribution and quartile analysis Keywords: Cosmic Deficit Index, CDI, Kp index, solar-terrestrial interaction, earthquake statistics, event-based analysis, Quartic Power Law, exploratory association study