A Three-Tier Volcanic Monitoring System for the Canary Islands

A Three-Tier Volcanic Monitoring System for the Canary Islands

This working paper presents a quantitative three-tier volcanic monitoring system for the Canary Islands, derived from the complete IGN seismic catalogue 2011–2026 (50,925 Canarian events). The system integrates a monthly Composite Loading Index (CLI) combining seismicity from the Alboran Sea and Cape Saint Vincent motor zones, relay indicators at the NW Tenerife node and Canal Enmedio (Beam B), and terminal sensors at La Palma and El Hierro.

Key findings: Saint Vincent → Tenerife is the strongest inter-island correlation (r=+0.435, p<0.0001, confirmed by Monte Carlo permutation tests at all lags 0–6 months), while Alboran does not predict Tenerife seismicity — a structural asymmetry consistent with the proposed Beam B architecture. El Hierro operates as an autonomous volcanic fuse (95% of seismicity variance explained internally; R²_motor=5%), with a negative motor correlation (r=−0.188) suggesting structural decoupling rather than suppression. Tenerife shows signs of chronic saturation: b-value >1.3 for nine consecutive years (2017–2026) and 10-km shallowing of median seismic depth since 2021.

A five-condition pre-eruptive protocol for La Palma/El Hierro (Arm A) is retrospectively validated against the full catalogue with zero false positives when all conditions are met simultaneously. Historical pre-eruptive analysis (1704–2021) identifies two mechanistic end-members: motor-driven eruptions (Teneguía 1971, Chinyero 1909, Chahorra 1798) and autonomous eruptions (El Hierro 2011, San Juan 1949). System state as of 21 April 2026: no pre-eruptive signature present for Arm A; Canal Enmedio at >P95 (Beam B relay active); El Hierro disconnected from external motor.

Working paper. Not peer reviewed. All statistical results are derived from publicly available IGN seismic catalogues downloaded in April 2026.