In a groundbreaking new study, researchers have unveiled a striking insight into the thermal dynamics of Earth’s subduction zones, driven by the unexpectedly high radiative conductivity of olivine. This mineral, a major component of the Earth’s upper mantle, appears to play a far more significant role in heat transfer within subducting slabs than previously recognized. The research reveals that olivine’s radiative heat transfer capabilities could elevate slab temperatures by as much as 200 degrees Kelvin, with profound implications for our understanding of deep Earth processes and tectonic activity.
At the core of this discovery is olivine’s capacity to conduct heat not just through conduction, the traditional mechanism widely studied in geophysics, but also through radiation—a mode of heat transfer where energy is propagated in the form of electromagnetic waves. Historically, the contribution of radiative heat transfer in mantle minerals like olivine has been downplayed or overlooked entirely in numerical models of slab thermodynamics. However, this new work provides compelling experimental evidence and theoretical modeling that radiative conductivity in olivine substantially boosts the effective thermal conductivity of subducted slabs.
This realization calls for a paradigm shift in how geoscientists model the thermal state of subduction zones. Until now, temperature predictions within slabs embedded deep beneath the Earth’s crust relied on conductivity values derived predominantly from conduction processes, leaving a substantial gap in the thermal budget. By integrating radiative conductivity—where photons carry heat energy through the crystal lattice—scientists now show that slabs may be considerably hotter than previously assumed, reshaping our interpretations of slab dehydration, melting, and ensuing volcanic activity above subduction zones.
The team, led by Marzotto and colleagues, employed an innovative combination of laboratory measurements at high temperatures and pressures simulating mantle conditions, complemented with sophisticated radiative transfer calculations. This multidisciplinary approach confirmed that olivine’s radiative conductivity scales significantly with temperature, surpassing conductive contributions beyond roughly 800 degrees Celsius. As slabs descend into the mantle, reaching temperatures where radiative transfer kicks in, the resulting heat fluxes are markedly enhanced.
By increasing slab temperatures by up to 200K, olivine’s radiative effects could accelerate metamorphic reactions that release fluids crucial for arc magmatism and influence the mechanics of slab-mantle interactions. This has extensive ramifications for the genesis of magmas, the localization of earthquakes, and chemical cycling in subduction zones, ultimately affecting volcanic hazards and continental growth.
Furthermore, the elevated slab temperatures may also help resolve longstanding discrepancies between observed surface heat flow in subduction regions and the cooler thermal models that have persisted for decades. Many previous models could not reconcile volcanic arc activity or seismicity patterns without assuming anomalously high frictional heat or fluid presence. The newly quantified radiative transfer by olivine now supplies a physically grounded mechanism to generate higher slab temperatures without invoking ad hoc assumptions.
Intriguingly, this finding reinforces the importance of accounting for all modes of heat transfer in geophysical modeling, particularly radiative transfer, which has often been minimized due to the dominant role of conduction in dense rocks. The crystal structure and lattice dynamics of olivine enable it to transmit thermal radiation efficiently at high mantle temperatures. This behavior contrasts with lower-temperature regimes, where radiative heat transfer is negligible, highlighting the necessity to contextualize mineral properties across temperature-pressure domains relevant to Earth’s interior.
The implications extend beyond Earth sciences, offering analogs for the interiors of rocky exoplanets with olivine-rich mantles. Understanding the balance of conductive and radiative processes in planetary interiors is critical for assessing their thermal evolution, potential tectonics, and habitability prospects.
Moreover, this breakthrough may influence seismic tomography interpretations. Higher slab temperatures modify seismic wave speeds, potentially altering the inferred mineralogical and thermal structure of slabs. As seismic imaging increasingly attempts to discern subtle variations in mantle composition, integrating radiative effects into thermal models becomes essential for correctly interpreting wave velocity anomalies.
From a methodological standpoint, achieving accurate measurement of radiative conductivity in natural minerals under extreme conditions represents a formidable experimental challenge. The researchers employed advanced spectroscopy and thermal conductivity measurement techniques, overcoming technical limitations that previously hindered quantification of radiative heat transfer. Their methodology paves the way for future studies to explore radiation-driven heat transfer in other deep Earth minerals, potentially revising global thermal models.
The comprehensive data set generated by the team reveals a strong temperature dependence of olivine’s radiative transfer, rising exponentially with increasing temperature, consistent with theoretical predictions of photon transport through crystalline lattices. This synergy between experimental and theoretical approaches adds robustness to their conclusions.
In conclusion, the revelation that olivine’s high radiative conductivity significantly raises slab temperatures necessitates a reevaluation of many geodynamic scenarios, from subduction zone thermal regimes to mantle convection dynamics. It highlights the necessity of incorporating radiative heat transfer into Earth models to accurately simulate the complex interplay of thermal, chemical, and mechanical processes shaping our planet’s interior.
As the geological community integrates this new understanding, it opens avenues for reinterpreting petrological data, seismic observations, and volcanic activity associated with subduction zones. The increase of up to 200K in slab temperature is not a minor tweak—it fundamentally reshapes thermal models that underpin our knowledge of Earth’s deep interior.
These findings affirm the intricacy and subtlety of mantle processes and underscore the continuing need for experimental innovation paired with theoretical rigor in Earth sciences. By uncovering olivine’s radiative conductivity as a previously underestimated thermal agent, this research shines new light on the hidden mechanisms heating our dynamic planet beneath its surface.
Subject of Research: Thermal conductivity of olivine and its effects on slab temperature in subduction zones
Article Title: Olivine’s high radiative conductivity increases slab temperature by up to 200K
Article References:
Marzotto, E., Koptev, A., Speziale, S. et al. Olivine’s high radiative conductivity increases slab temperature by up to 200K. Nat Commun 16, 6058 (2025). https://doi.org/10.1038/s41467-025-61148-8
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