Carbon fluxes in subduction zones can be better constrained by including new estimates of carbon concentration in subducting mantle peridotites, consideration of carbonate solubility in aqueous fluid along subduction geotherms, and diapirism of carbon-bearing metasediments. Whereas previous studies concluded that about half the subducting carbon is returned to the convecting mantle, we find tha...

Although plate tectonics is well established, how a new subduction zone initiates remains controversial. Based on plate reconstruction and recent ocean drilling within the Izu-Bonin-Mariana, we advance a new geodynamic model of subduction initiation (SI). We argue that the close juxtaposition of the nascent plate boundary with relic oceanic arcs is a key factor localizing initiation of this new...

While modelling studies suggest that mesoscale eddies strengthen the subduction of mode waters, this eddy effect has never been observed in the field. Here we report results from a field campaign from March 2014 that captured the eddy effects on mode-water subduction south of the Kuroshio Extension east of Japan. The experiment deployed 17 Argo floats in an anticyclonic eddy (AC) with enhanced ...

[1] We present three‐dimensional laboratory modeling of the evolution of finite strain and compare these to shear wave splitting observations in the Northwest U.S. under the High Lava Plains (HLP). We show that relationships between mantle flow and anisotropy are complicated in subduction zones and factors such as initial orientation of the olivine fast‐axis, style of subduction, and time evolv...

Recent geochemical studies of uranium-thorium series disequilibrium in rocks from subduction zones require magmas to be transported through the mantle from just above the subducting slab to the surface in as little as approximately 30,000 years. We present a series of laboratory experiments that investigate the characteristic time scales and flow patterns of the diapiric upwelling model of subd...

Subduction zones form dominant tectonic features on the Earth and are the site of large underthrusting earthquakes and explosive arc volcanism. They are also the only locations with deep earthquakes in the Earth’s interior. Major questions remain regarding the dynamics of subduction zones, including aspects such as the role of water in the formation of arc volcanism and deep earthquakes, the in...

Much of the Earth’s mantle was melted in the Moon-forming impact. Gases that were not partially soluble in the melt, such as water and CO2, formed a thick, deep atmosphere surrounding the postimpact Earth. This atmosphere was opaque to thermal radiation, allowing heat to escape to space only at the runaway greenhouse threshold of approximately 100 W m−2. The duration of this runaway greenhouse ...

Much of my research career has been spent working both on modern oceanic volcanic systems and at the same time looking at their Archaean counterparts. Many authors have attempted to make inferences on early Earth models based on modern processes which can be increasingly well constrained. In this short review I show how we are beginning to understand and quantify inputs to modern subduction sys...

Several lines of evidence suggest that simple subduction with one downgoing and one overriding plate is an insufficient model of the Cascadia Subduction Zone. Instead, the subduction zone and arc are segmented, exhibiting variations in multiple characteristics along strike. One line of evidence comes from the analysis of seismicity. The subduction zone is atypical everywhere in that the Wadati-...

a r t i c l e i n f o Plate tectonics is a self-organizing global system driven by the negative buoyancy of the thermal boundary layer resulting in subduction. Although the signature of plate tectonics is recognized with some confidence in the Phanerozoic geological record of the continents, evidence for plate tectonics becomes less certain further back in time. To improve our understanding of ...