Two decades of placing subduction-themed MARGINS and GeoPRISMS field experiments in a multidisciplinary framework

Abstract:

MARGINS and GeoPRISMS were built around several community needs: understanding complicated systems in a meaningful process-driven way, seamlessly crossing the shoreline, and focus on high-value sites to address problems in subduction, rifting, and sediment transport. I have had the opportunity to participate in several field projects directly, and to collaborate with a broad swath of the community. The field projects include broadband seismic field experiments targeting the melting regime and downgoing plate of subduction zones, notably TUCAN 2003-6 in Central America, iMUSH in Mount St Helens in 2013-16, and AACSE on and off the Alaska Peninsula in 2018-20. Although each consists of a multi-PI deployment of seismometers onshore or on the sea floor, they all were designed, analyzed and interpreted with close collaboration of scientists in other disciplines. The TUCAN array was designed in close cooperation with arc geochemists (Ba/La and seismometers appear on the same maps). iMUSH included a small army of petrologists, and volcanologists, and electromagnetic experts. The AACSE community experiment grew out of workshops and meetings where earthquake/tsunami hazard, arc volcanology and marine geology all informed the needs. All of these were built around a framework of thermal, petrological and fluid-cycling models and laboratory studies that could put the site-specific work in global context. This model of cross-disciplinary articulation of problems directly informing disciplinary projects, and feeding the data from these projects back into broader community syntheses, may well be the most lasting legacy of MARGINS and GeoPRISMS. It is a model that now seems natural across solid-earth geoscience, and is a real achievement of all involved.