The Aleutian-Alaska Subduction Zone: An Unparalleled Natural Laboratory for Understanding Arc Volcanic Processes
Abstract
Over the past several decades, multidisciplinary research focused on the Aleutian-Alaska Subduction Zone (AASZ) has provided a wealth of knowledge that continues to grow via research supported by monitoring organizations and initiatives, such as the Alaska Volcano Observatory, GeoPRISMS, SZ4D, the Deep Carbon Observatory, and the Community Network for Volcanic Eruption Response. The AASZ is a complex, segmented arc that has a rich and diverse magmatic and volcanic history. Magma production and volcanism appear to be linked, at least in part, to changes in convergence angle, mantle wedge melting, crustal thickness and structure, and sediment input along strike. Frequent volcanic eruptions, combined with a record of magmatic intrusions preserved in plutons, make the AASZ an unparalleled natural laboratory for investigating how arc magmatic processes evolve in space and through time. Outstanding questions remain that are well-suited to continuing research along the AASZ, as well as in comparison with other subduction zones around the world: 1) What controls the spatial and temporal patterns of volcanism across the AASZ (e.g., Buurman et al., 2014; Till et al., 2019)? Ongoing research seeks to establish whether changes in mantle-sourced magma/fluid flux, or crustal structural controls, or some combination of those, are predominant in creating the observed patterns of volcanism along the arc. 2) How do subduction inputs (sediments, fluids) cycle through the arc and how do they influence the outputs (magma composition, gas chemistry)? 3) How fast and by what pathways do magmas move through the crust, and what controls the accumulation (or not) of established crustal magma reservoirs (e.g., McGuire, Plank, et al., 2017)? Linking the origination, transport, and storage of magma and fluids through the arc crust with geophysical and gas monitoring data during episodes of unrest and eruption will allow scientists to ultimately improve eruption forecasting. This presentation will explore these questions using examples from recent research in the AASZ, with a view towards future discoveries.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.T51A..01L
- Keywords:
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- 1037 Magma genesis and partial melting;
- GEOCHEMISTRY;
- 8170 Subduction zone processes;
- TECTONOPHYSICS;
- 8178 Tectonics and magmatism;
- TECTONOPHYSICS;
- 8185 Volcanic arcs;
- TECTONOPHYSICS