Dyke apertures record stress accumulation during sustained volcanism

The interaction between magma intrusions and stress evolution in volcanic systems remains unclear, despite its role in magma transport and volcanic instability. Long-lived ocean island volcanoes contain thousands of dykes, which are accommodated through flank slip and visco-elastic deformation. Flank slip is observed in some systems, like Kilauea, but the mechanisms in others are unresolved. Prior research has shown that dykes can influence stress fields and magma pathways. However, the specific feedback between intrusion geometry and stress accumulation is not fully understood. This gap motivated a detailed study of dyke and sill intrusions in a specific volcanic setting. The lack of comprehensive data on dyke apertures and orientations has limited progress in this area. This paper contributes by analyzing a large dataset from a single volcanic system to infer stress evolution during sustained volcanism.

The study aimed to investigate how dyke intrusions and stress evolution interact in long-lived volcanic systems. The focus was on Volcán Taburiente in the Canary Islands, where thousands of dykes are present. The goal was to determine how these intrusions are accommodated through deformation mechanisms. The researchers sought to understand the relationship between dyke orientation, aperture, and stress accumulation. They aimed to test whether visco-elastic deformation could explain dyke deflection and stress buildup. The study also aimed to assess how stress accumulation might influence eruptive migration. By analyzing a large dataset of dyke measurements, the authors hoped to model magma transport and instability mechanisms. This approach allows for a more detailed understanding of how volcanic systems evolve over time.

The researchers used digital mapping to collect over 400,000 measurements of dyke orientation and aperture from 519 sheet intrusions. These data were gathered from Volcán Taburiente in La Palma, Canary Islands. The mapping focused on vertical and lateral propagation patterns of dykes. The team analyzed how dykes transitioned from vertical ascent to lateral propagation near the surface. They proposed a visco-elastic model to explain the accommodation of these intrusions. The model was tested against the observed dyke-aperture distribution. The study combined field observations with numerical modeling to infer stress accumulation patterns. The results were used to predict how stress might block subsequent dykes and influence eruptive migration.

The study found that vertically ascending dykes were deflected to propagate laterally as they neared the volcano's surface. This led to the formation of a radial dyke swarm. The measured dyke-aperture distribution was successfully reproduced by the visco-elastic model. The model predicted that stress accumulates in densely intruded regions of the volcano. This stress buildup blocks subsequent dyke intrusions, causing eruptive activity to migrate. The results indicate that visco-elastic deformation is a key mechanism for accommodating dykes. The findings suggest that stress evolution is closely linked to magma transport and eruptive behavior. These results provide new insights into how volcanic systems maintain stability over long timescales.

The authors propose that visco-elastic deformation accommodates dyke intrusions in Volcán Taburiente. They suggest that stress accumulates in densely intruded regions, blocking new dykes and causing eruptive migration. The radial dyke swarm observed in the study supports the model's predictions. The findings imply that stress evolution is a critical factor in magma transport and eruptive behavior. The study highlights the importance of integrating field data with numerical modeling in volcanic systems. The results do not assign essentiality to any single mechanism but suggest visco-elastic deformation as a plausible explanation. The authors emphasize that these findings are specific to Volcán Taburiente and may not generalize to all volcanic systems. The study contributes to understanding how stress and magma transport interact in long-lived volcanoes.