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Yellowstone's vigorous hydrothermal system has long been recognized, but it remains challenging to quantify its magmatic heat supply. Here, we use two controlled-source seismic reflection transects and 3-D passive-source tomography to guide a simple model of magmatic heat supply coupled to a thermodynamic model of hydrothermal reservoir convection. Key model properties are the surface area of the magmatic-hydrothermal interface, conductive-boundary-layer thickness, and the temperature difference between the top of the magma reservoir and the base of the hydrothermal system. Magmatic temperature is set to an estimated rhyolite solidus, and the base of the hydrothermal system is estimated near the critical point for water. Seismic reflections are consistent with a conductive boundary layer thickness of ~120 m or less, and a shear-velocity-tomography contour that encloses the reflections has an area of ~1190 km2 (40% of the 0.63 Ma caldera). The magmatic heat supply model predicts at least 7.5 GW, which is consistent with a prior geochemical estimate of 6.6 GW of output to surface water and ~12% convective heat loss. The new results support the feasibility of system-scale geothermal budget estimation for onshore magmatic and hydrothermal reservoirs. 

Abstract We apply a machine learning (ML) earthquake detection technique on over 21 yr of seismic data from on-continent temporary and long-term networks to obtain the most complete catalog of seismicity in Antarctica to date. The new catalog contains 60,006 seismic events within the Antarctic continent for 1 January 2000–1 January 2021, with estimated moment magnitudes (Mw) between −1.0 and 4.5. Most detected seismicity occurs near Ross Island, large ice shelves, ice streams, ice-covered volcanoes, or in distinct and isolated areas within the continental interior. The event locations and waveform characteristics indicate volcanic, tectonic, and cryospheric sources. The catalog shows that Antarctica is more seismically active than prior catalogs would indicate, examples include new tectonic events in East Antarctica, seismic events near and around the vicinity of David Glacier, and many thousands of events in the Mount Erebus region. This catalog provides a resource for more specific studies using other detection and analysis methods such as template matching or transfer learning to further discriminate source types and investigate diverse seismogenic processes across the continent. 

Along subduction zones, high-relief topography is associated with sustained volcanism parallel to the plate margin. However, the relationship between magmatism and mountain building in arcs is poorly understood. Here, we study patterns of surface deformation and correlated fluvial knickpoints in the Columbia River Gorge to link long-term magmatism to the uplift and ensuing topographic development of the Cascade Range. An upwarped paleochannel exposed in the walls of the Gorge constrains unsteady deep magma flux, the ratio of intrusive to extrusive magmatic contributions to topography, and the impact of magmatism on Co- lumbia River incision since 3.5 million years ago. Geophysical data indicate that deep magma influx beneath the arc axis is ongoing and not aligned with the current locations of volcanic edifices, representing a broad regional influence on arc construction. 

Seismic imaging shows a melt fraction of up to 20% in the depth range that supplied prior Yellowstone eruptions.