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Abstract The architecture of magma plumbing systems plays a fundamental role in volcano eruption and evolution. However, the precise configuration of crustal magma reservoirs and conduits responsible for supplying eruptions are difficult to explore across most active volcanic systems. Consequently, our understanding of their correlation with eruption dynamics is limited. Axial Seamount is an active submarine volcano located along the Juan de Fuca Ridge, with known eruptions in 1998, 2011, and 2015. Here we present high-resolution images of P-wave velocity, attenuation, and estimates of temperature and partial melt beneath the summit of Axial Seamount, derived from multi-parameter full waveform inversion of a 2D multi-channel seismic line. Multiple magma reservoirs, including a newly discovered western magma reservoir, are identified in the upper crust, with the maximum melt fraction of ~15–32% in the upper main magma reservoir (MMR) and lower fractions of 10% to 26% in other satellite reservoirs. In addition, a feeding conduit below the MMR with a melt fraction of ~4–11% and a low-velocity throat beneath the eastern caldera wall connecting the MMR roof with eruptive fissures are imaged. These findings delineate an asymmetric shallow plumbing system beneath Axial Seamount, providing insights into the magma pathways that fed recent eruptions. 

GeophysicsTwo-dimensional seismic Vp profile from Dunn et al. (2023), including positions of the seafloor, the upper reflector, and the lower reflector along the profile. The Vp model is in netCDF-4 format and the others are in ascii format and contain the position along the line and depth below sea level. The origin of the profile is 21.48865˚N, 158.49115˚W, and the azimuth of the profile is 15,1˚ from north.Reference: R. A. Dunn, A. B. Watts, C. Xu, and D. J. Shillington (2023) A seismic tomography, gravity, and flexure study of the crust and upper mantle structure across the Hawaiian Ridge, Part 2 Ka‘ena, Journal of Geophysical Research - Solid Earth. 

Abstract Backscatter interferometry (BSI) is a refractive index (RI) detection method that is easily integrated with capillary electrophoresis (CE) and is capable of detecting species ranging from inorganic ions to proteins without additional labels or contrast agents. The BSI signal changes linearly with the square of the separation voltage which has been used to quantify sample injection, but has not been explored as a potential signal enhancement mechanism in CE. Here we develop a mathematical model that predicts a signal enhancement at high field strengths, where the BSI signal is dominated by the voltage dependent mechanism. This is confirmed in both simulation and experiment, which show that the analyte peak area grows linearly with separation voltage at high field strengths. This effect can be exploited by adjusting the background electrolyte (BGE) to increase the conductivity difference between the BGE and analyte zones, which is shown to improve BSI performance. We also show that this approach has utility in small bore capillaries where larger separation fields can be applied before excess Joule heating degrades the separation. Unlike other optical detection methods that generally degrade as the optical pathlength is reduced, the BSI signal-to-noise can improve in small bore capillaries as the larger separation fields enhance the signal. 

Two-dimensional seismic Vp profile from MacGregor et al. (2023), including positions of the seafloor, the upper reflector, and the lower reflector along the profile. The Vp model is in netCDF-4 format and the others are in ascii format and contain the position along the line and depth below sea level. The origin of the profile is 20.49˚N, 155.8237˚W, and the azimuth of the profile is 46˚ from north.Reference: MacGregor, B. G., Dunn, R. A., Watts, A. B., Xu, C., & Shillington, D. J. (2023). A seismic tomography, gravity, and flexure study of the crust and upper mantle structure of the Hawaiian Ridge: 1. Journal of Geophysical Research: Solid Earth, 128, e2023JB027218. https://doi. org/10.1029/2023JB027218 

Abstract The bulk of research on citizen science participants is project centric, based on an assumption that volunteers experience a single project. Contrary to this assumption, survey responses (n = 3894) and digital trace data (n = 3649) from volunteers, who collectively engaged in 1126 unique projects, revealed that multiproject participation was the norm. Only 23% of volunteers were singletons (who participated in only one project). The remaining multiproject participants were split evenly between discipline specialists (39%) and discipline spanners (38% joined projects with different disciplinary topics) and unevenly between mode specialists (52%) and mode spanners (25% participated in online and offline projects). Public engagement was narrow: The multiproject participants were eight times more likely to be White and five times more likely to hold advanced degrees than the general population. We propose a volunteer-centric framework that explores how the dynamic accumulation of experiences in a project ecosystem can support broad learning objectives and inclusive citizen science.