Understanding the controls for magma ascent and storage depth is important for volcanic hazard assessment. Regional differences in the depths of magma storage between volcanic arcs suggest that the settings of subduction zones and of overriding plates influence howmagma ascends through the crust. Here we use a compilation of data for 70 volcanoes in 15 volcanic regions to better understand the ...

[1] To investigate the possible physical mechanisms of recently observed aseismic slip events in the Cascadia, Japan and Mexico subduction zones, we apply a Dieterich-Ruina rate and state friction law to a three dimensional model of a shallow subduction fault. That is loaded by imposed steady plate slip rate far downdip along the thrust interface. Friction properties are temperature and hence d...

Quantifying the precise thermal structure of subduction zones is essential for understanding the nature of metamorphic dehydration reactions, arc volcanism, and intermediate depth seismicity. High resolution twodimensional (2-D) models have shown that the rheology of the mantle wedge plays a critical role and establishes strong temperature gradients in the slab. The influence of threedimensiona...

The emission of methane and the higher hydrocarbons is observed in both mid-ocean ridge and subduction-related hydrothermal systems. It has been recently reported that methane emanating from an extensional ultramafichydrothermal system originates from the abiogenic reduction of (mantle) CO2 (1). The same process is also known to occur in subaerial subduction-related systems (2). These findings ...

a r t i c l e i n f o a b s t r a c t Southern Peru is located in the northern Central Andes, which is the highest plateau along an active subduction zone. In this region, the Nazca slab changes from normal to flat subduction, with the associated Holocene volcanism ceasing above the flat subduction regime. We use 6 s to 67 s period surface wave signals from ambient noise cross-correlations and ...

Active microplate boundaries in ocean-continent subduction zones may induce deformation of the overlying plate and spatial or geochemical variations in the volcanic arc. We discuss two modern cases. The first is the South Gorda-Juan de Fuca plate boundary in the Cascadia subduction zone, where there is little or no effect on the overriding plate and the oceanic plate takes up much of the deform...

Models explaining the characteristic depletion of High Field Strength Elements (HFSE) relative to elements of similar compatibility in subduction zone magmas invoke either (1) the presence of HFSE-rich minerals in the subduction regime or (2) a selectively lower mobility of HFSE during subduction metasomatism of the mantle. In order to investigate the properties of HFSE in subduction regimes cl...

-While most aspects of subduction have been extensively studied, the process of subduction initiation lacks an observational foundation. The Macquarie Ridge complex (MRC) forms the Pacific-Australia plate boundary between New Zealand to the north and the Pacific-Australia-Antarctica triple junction to the south. The MRC consists of alternating troughs and rises and is characterized by a transit...

9 10 This paper makes a review of the interpretations of the tectonic evolution of SW Japan 11 during the last three decades. In the late 1970s, the dominant model was the so-called 12 ―Pacific-type orogeny‖, emphasizing the purported absence of nappes and the contrast with 13 the alpine chains, and interpreting the evolution as due to a steady oceanic subduction since 14 the Paleozoic time. In...