Volcanic Activity and Tectonics in Subduction Zones

Subduction zones, where one lithospheric plate descends beneath another, are the principal loci of arc volcanism and intense seismic activity. The release of volatiles from the subducting slab induces partial melting in the overlying mantle, generating magmas that ascend through the crust to feed volcanoes aligned parallel to the trench. Tectonic forces in these regions drive complex patterns of stress accumulation and release, influencing the geometry of faults and the pathways of fluids and melts. The interplay of deep-slab dehydration, crustal deformation and local stress regimes governs the frequency and style of eruptions, as well as the distribution of geothermal resources. Advances in geodesy, seismic imaging, geochemical analysis and numerical modelling have illuminated the dynamics of magma storage, migration and eruption, while remote sensing and geomorphic mapping have exposed cryptic structures controlling magmatic and hydrothermal circulation. This convergence of disciplines enhances hazard assessment, informs geothermal exploration and elucidates the fundamental mechanisms that underpin volcanic arcs worldwide.

Research from Nature Portfolio

By analysing earthquake focal mechanisms, fault-slip data and Monte Carlo simulations, researchers have characterised three end-member stress patterns within the Andean Southern Volcanic Zone. An extensional regime linked to magma inflation emerges as a target for geothermal exploration, while fluid-driven stress rotations appear to herald impending eruptions in historically active volcanoes.

Off-fault geomorphology has revealed the hidden architecture of a blind normal fault in coastal Chile, demonstrating that surface terraces and satellite geodesy can yield slip rates and recurrence intervals for magnitude-7 earthquakes. The findings underscore the seismic potential of cryptic faults above subduction megathrusts.

Major- and trace-element analysis of glass shards from a high-magnitude fissure eruption in southern Chile has shown that multiple magma bodies can be simultaneously tapped during explosive events. This work highlights the role of fault-zone architecture in impeding magma ascent and fostering discrete sub-volcanic reservoirs.

Volcanic Activity and Tectonics in Subduction Zones publication trend

The graph below shows the total number of articles in volcanic activity and tectonics in subduction zones across all publications each year (not limited to Nature Index journals).

Technical terms

Subduction zone: A convergent plate boundary where an oceanic plate sinks beneath another plate, generating magmatism and seismicity.

Magma reservoir: A subsurface accumulation of molten rock that evolves chemically and thermally before eruption.

Blind fault: A crustal fracture that does not rupture the surface but influences deformation and seismic hazard.

Tephra: Fragmental volcanic material ejected during explosive eruptions, including ash, lapilli and bombs.

Stress regime: The orientation and magnitude of tectonic forces acting within the Earth's crust.

References

1. Decoding the state of stress and fluid pathways along the Andean Southern Volcanic Zone. Communications Earth & Environment (2023).
2. The cryptic seismic potential of the Pichilemu blind fault in Chile revealed by off-fault geomorphology. Nature Communications (2022).
3. Multiple melt bodies fed the AD 2011 eruption of Puyehue-Cordón Caulle, Chile. Scientific Reports (2015).
4. A comprehensive database of active and potentially-active continental faults in Chile at 1:25,000 scale. Scientific Data (2021).
5. Insights Into Magma Storage Beneath a Frequently Erupting Arc Volcano (Villarrica, Chile) From Unsupervised Machine Learning Analysis of Mineral Compositions. Geochemistry Geophysics Geosystems (2022).
6. Late Quaternary tephrostratigraphy of southern Chile and Argentina. Quaternary Science Reviews (2014).