High-resolution seismic imaging enables the reconstruction of ascending paths of magma and fluids, shallow molten accumulation and flank collapse areas, all crucial information for developing an efficient eruption forecasting strategy. Here, the Marching Cubes algorithm (MC -generally applied to medical visualization and three-dimensional (3D) modeling) is applied to 16 years of earthquake location data at Mt. Etna (Italy). The algorithm defines three-dimensional seismic clusters that take into account seismic location uncertainties and are embedded in a novel volcanooriented Geographyc Information Systems (VolGIS) offering an interpretational environment comprising tomographic images and alternative geophysical models. The results show that a volume of very-low-seismicity is embedded in a high-velocity body, and acts as a zone of transition between transient magmatic events (west) and eastern deep seismicity related to the sliding eastern flank. The eastern cluster represents the 3D seismic signature of a deep (2-8 km below sea level) instability, affecting the portion of the eastern flank nearest to the feeding systems. This instability is likely caused by a combination of gravitational spreading and magmatic intrusions.

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Active seismic experiments allow reconstructing the subsurface structure of volcanoes with unprecedented resolution and are vital to improve the interpretation of volcanic processes. They require a quality assessment for thousands of seismic waveforms recorded at hundreds of stations in the shortest amount of time. However, the processing necessary to obtain reliable images from such massive datasets demands signal processing and selection strategies specific to the inversions attempted. Here, we present a semi-automated workflow for data selection and inversion of amplitude-dependent information using the original TOMODEC2005 dataset, recorded at Deception Island (Antarctica). The workflow is built to tomographic techniques using amplitude information, and can be generalised to passive seismic imaging. It first selects data depending on standard attributes, like the presence of zeroes across all seismic waveforms. Then, waveform selections depend on inversion-specific attributes, like the delay of the maximum amplitude of the waveform or the quality of coda-wave decays. The automatic workflow and final visual selections produce a dataset reconstructing anomalies at a node spacing of 2 km, imaging a high-attenuation anomaly in the centre of the Deception Island bay, consistent with previously-published maps. Attenuation models are then obtained at a node spacing of 1 km, highlighting bodies of highest attenuation scattered across the island and a NW-SE trend in the high-attenuation anomaly in the central bay. These results show the effect of the local extension regime on volcanic structures, providing details on the eruptive history and evolution of the shallow magmatic and hydrothermal systems. The selection workflow can be easily generalised to other amplitude-dependent tomographic techniques when applied to active seismic surveys. Image improvements from the original dataset are minor when selecting data using standard attributes, like signal-to-noise ratios. Tomographic maps become drastically more stable and consistent between different frequencies and resolutions when data selection targets attributes specific to the inversion.

<p>The DIVEnet is the ICDP DIVE project dedicated seismographic network. The ICDP DIVE project (www.dive2ivrea.org) is aimed at addressing fundamental questions on the nature of the lower continental crust and its transition to the mantle through two drillings in the Ivrea Verbano zone (IVZ), considered the world's best outcrop of lower crustal continental rocks. Between September and December 2022 the first drilling has been done in Ornavasso. To be ready for its monitoring the DIVEnet has started to record continuously since November 2021. <br />The network includes 11 seismic stations located within a 17.7 km radius from the drilling site. Additionally, the stations from the CH (Switzerland), GU (University of Genova) and IV (INGV) networks are used to locate the detected earthquakes. </p> <p>Before the beginning of the drilling the acquired data have been analyzed checking for daily and sub-daily continuity and, when needed, recovery acquisition gaps. After the data recovery, the total loss in the period span between November 2021 and 20 December 2022, date when the drilling stopped, is less than 2% and 5% in daily and sub-daily missing data, respectively. <br />Furthermore, probabilistic power spectral densities (PPSD) analysis has been conducted monthly and for the entire period (11-2021 / 12-2022).</p> <p>The drilling started on the 6 of October, showing no significant changes in the noise spectrum at each station, included those close to the drilling site. Real time analysis has been conducted from the beginning of the drilling with the automatic detection of local earthquakes counting less than 20 small events in the period between 1 October and 20 December.</p> <p>Several automated codes have been developed to daily analyze, localize and eventually plot on map the events falling inside the network. Currently the workflow include a set of Python scripts followed by SeisComP calls for automatic earthquakes detection and localization;  the set of scripts comprises codes to: daily checks for earthquakes, weekly checks for gaps and, if necessary, download lost data, monthly analysis of PPSD and HTML-report creation with map location earthquakes. </p> <p>This routine would make future analysis faster and cleaner during the second drilling planned in Megolo in spring 2023 as well as other real time seismic analysis.</p>

<p>Deception Island is the most active and documented volcano in the South Shetland Islands (Antarctica). Since its last eruption (1970) several experiments have targeted the reconstruction of its magmatic systems. Geophysical imaging has provided new insight into Deception's interior, particularly when using space-weighted seismic attenuation tomography for coda waves. Here, sensitivity kernels have been used to invert coda wave attenuation (Q<sub>c</sub><sup>−1</sup>). We obtain a multifrequency-dependent model of the magmatic systems at Deception Island using active data, paying particularly attention to data selection and model optimisation. The results have been framed in the extensive knowledge of the tectonics and the geomorphology of the volcano with a GIS, underlining a spatial correlation between high-attenuation anomalies and high thermal activity regions. This inter- and multi-disciplinary analysis improves the interpretation of the dynamics of Deception Island and its related hazards.</p>

Deception Island is one of the most active and best‐documented volcanoes in Antarctica. Since its last eruption in 1970, several geophysical surveys have targeted reconstructing its magmatic systems. However, geophysics fails to reconstruct the pathways magma and fluids follow from depth to erupt at the surface. Here, novel data selection strategies and multi‐frequency absorption inversions have been framed in a Geographical Information System, using all available geological (vents and faults distribution), geochemical and geophysical knowledge of the volcano. The result is the detection of these eruptive pathways. The model offers the first image of the magma and associated fluids pathways feed the 1967, 1969, and 1970 eruptions. Results suggest that future ascending paths might lead to active research bases and zones of planned helicopter rescue. The connection between seismic absorption, temperature, and fluid content makes it a promising attribute for detecting and monitoring eruptions at active calderas.