The session deals with the documentation and modelling of the tectonic, deformation, and geodetic features of any type of volcanic area, on Earth and in the Solar System. The focus is on advancing our understanding on any type of deformation of active and non-active volcanoes, on the associated behaviours, and the implications for hazards. We welcome contributions based on results from fieldwork, remote-sensing studies, geodetic and geophysical measurements, analytical, analogue and numerical simulations, and laboratory studies of volcanic rocks. We also welcome multidisciplinary studies, especially those that integrate data collected at different scales (e.g. laboratory and field data).
Studies may be focused at the regional scale, investigating the tectonic setting responsible for and controlling volcanic activity, both along divergent and convergent plate boundaries, as well in intraplate settings. At a more local scale, all types of surface deformation in volcanic areas are of interest, such as elastic inflation and deflation, or anelastic processes, including caldera and flank collapses. Deeper, sub-volcanic deformation studies, concerning the emplacement of intrusions, as sills, dikes, and laccoliths, are most welcome.
We also particularly welcome geophysical data aimed at understanding magmatic processes during volcano unrest. These include geodetic studies obtained mainly through GPS and InSAR, as well as studies that model these data to image sources.


The session includes, but is not restricted to, the following topics:
• volcanism and regional tectonics;
• formation of magma chambers, laccoliths, and other intrusions;
• dyke and sill propagation, emplacement, and arrest;
• earthquakes and eruptions;
• caldera collapse, resurgence, and unrest;
• flank collapse;
• volcano deformation monitoring;
• volcano deformation and hazard mitigation;
• volcano unrest;
• mechanical properties of rocks in volcanic areas.

Interaction between the different phases (exsolved and dissolved volatiles, liquid melt, crystals, and pyroclasts) that separate during magma evolution, ascent and storage as a result of interlinked fluid, thermodynamic and chemical processes have a dramatic influence on eruption dynamics, resulting in a plethora of explosive eruptions types.
On one side, constraining volatile budget in magmas and quantifying degassing processes is a fundamental task to better understand the role of volatile elements on eruption dynamics. On the other side, the complex shallow plumbing system dynamics produces seismic and acoustic events, ground deformation and changes in the hydrothermal system often preceding or follow the explosive activity and direct field observations can constrain individual eruptive processes.
For this reason, the session aims at gathering field observation and experimental and modeling studies on eruptive processes to unlock the complex dynamics of volcanic activity. We hereby invite contributions focusing on (but not restricted to) volatiles in magmas, crystallization dynamics, effusive/explosive transition, rheology of gas-liquid-solid mixtures, fragmentation processes.
Further, we like to stimulate discussion on how multidisciplinary approaches can be used to advance the interpretation of geochemical and petrological observations on magmatic products and more specifically on the quantification of disequilibria processes during volcanic eruptions.

Over the past few years, major technological advances allowed to significantly increase both the spatial coverage and frequency bandwidth of multi-disciplinary observations at active volcanoes. Networks of instruments for the quantitative measurement of many parameters now permit an unprecedented, multi-parameter vision of the surface manifestations of mass transport beneath volcanoes. Furthermore, new models and processing techniques have led to innovative paradigms for inverting observational data to image the structures and interpret the dynamics of volcanoes. Within this context, this session aims at bringing together a multidisciplinary audience to discuss the most recent innovations in volcano imaging and monitoring, and to present observations, methods and models that increase our understanding of volcanic processes.
We welcome contributions (1) related to methodological and instrumental advances in geophysical, geological and geochemical imaging of volcanoes, and (2) to explore new knowledge provided by these studies on the internal structure and physical processes of volcanic systems.
We invite contributors from all geophysical, geological and geochemical disciplines such as seismology, electromagnetics, geoelectrics, gravimetry, magnetics, muon tomography, volatile measurements and analysis; from in-situ monitoring networks to high resolution remote sensing and innovative processing methods, applied to volcanic systems ranging from near-surface hydrothermal activity to magmatic processes at depth.

In response to a Horizon2020 call to Integrate and open European research infrastructures of starting communities a successful proposal from the European volcanological community, including key research infrastructures and stakeholders resulted in funding of the EUROVOLC project, the first integrating activity in volcanology. In addition to enabling open access for European researchers to key volcanological research infrastructures and data, as well as carrying out joint research activities to enhance the services offered by the infrastructures, the underlying aim of EUROVOLC is to overcome the fragmentation of the volcanological community and the widely distributed infrastructures by developing dynamic connections and collaborations within the community and between the community and its stakeholders. The EUROVOLC consortium includes all the main European volcano observatories and many of the strongest volcano research institutions, Civil Protection agencies, geothermal industry and IT companies. This ensemble has since early 2018 carried out a variety of Networking, Joint Research and Virtual Access activities. The group has also issued two open research calls offering Trans-national Access to the research infrastructures and successfully organized a summer school for young scientists. The session will highlight the networking, data, products, services, accesses and research achieved in EUROVOLCs many activities. The session also welcomes contributions from the research projects funded through EUROVOLCs Trans-national grants, to more fully demonstrate the research opportunities made available by EUROVOLC.

Active tectonics and volcano-tectonic processes are related to earthquakes, fracturing, fault motion (such as creeping), volcanic eruptions, caldera or flank collapse and magmatic intrusions, such as dyking. Satellite data using optical or thermal sensors provide first order information about faulting and volcanic activity, however, there is a resolution gap below the meter-scale, critical to detect and analyse small structures over broad areas and to better assess how faults, magma intrusions and collapses nucleate and evolve. During large deformations (earthquakes, dyke intrusions, collapses), the near-field area where satellite radar signal (InSAR) becomes incoherent remains poorly studied. In addition, classical field surveys and data collection are, very often, not feasible due to difficult logistic condition, hazardous accesses and/or inaccessible areas. Therefore, there is a need to collect higher resolution data to better understand faulting and volcanic processes at scales from cm to several meters, that complement classical field studies and satellite data. The scientific community has adopted modern direct and indirect methods to develop in the last decade, like the Structure from Motion (SfM) techniques.
SfM techniques have been applied using imagery acquired from field and aerial survey, using cameras and mobile phones, Unmanned Aerial Vehicles (UAVs, i.e. drones), balloons, airplanes and helicopters. This technique produces digital surface models (DSM), ortho-mosaic imagery, dense point clouds and 3D models, creating a high-resolution environment reconstruction for a single outcrop or a wide area. The session will focus on the application of the SfM techniques for research in the field of structural geology, with particular regard to active tectonics and volcano-tectonic processes. The session covers, without being limited to, the following topics: i) case studies where the SfM has been employed; ii) SfM methods, 3D reconstruction and successive analysis; iii) innovative application for SfM for survey, such as ground deformation analysis; iv) integration and comparison of SfM-derived, field and satellite data; v) new tools and methods for data analysis on SfM-derived models; and vi) future works and applications of SfM techniques.

Seismology is fundamental for monitoring and investigating volcanic systems.
Volcanoes are complex systems comprising both time-varying processes and structural heterogeneity. This combination of wide-ranging complex processes, extreme geomechanical heterogeneity, frequently rapid changes in time, leads to challenges in interpreting seismic observations in terms of physical processes at depth. In addition, the link between the variety of physical processes beneath volcanoes and their seismic response (or lack of) is often poorly understood, making it difficult to develop a detailed understanding of the physical processes at work in volcanic systems.
To address these challenges, this session aims to bring together seismologists, volcano and geothermal seismologists, and wave propagation and source modellers working on different aspects of volcano seismology including but not limited to: (i) seismicity catalogues (statistics & spatio-temporal evolution of seismicity), (ii) innovative methods for source locations (iii) source inversions (iv) seismic wave propagation & scattering, (v) small scale deformation studies, (vi) new developments in volcano imagery, (vii) time-lapse studies – including the use of noise, multiplets and high-rate GPS. Studies on geothermal systems in volcanic environments are also welcome.
By considering interrelationships between these complementary seismological areas, we aim to develop a coherent picture of the latest advances, successful applications and outstanding challenges in volcano seismology.

Public information:
SCHEDULE

16:15 Start of the session
Introduction

16:20 Guardo et al.: “Space-weighted seismic attenuation multi-frequency tomography at Deception Island volcano (Antartica)” (EGU2020-9986)

16:25 Eibl et al.: “Rotational sensor on a volcano: New insights from Etna, Italy” (EGU2020-18862)

16:30 Gabrielli et al.: “Geomorphological controls on seismic recordings in volcanic areas” (EGU2020-511)

16:35 Metaxian et al.: “Towards real-time monitoring with a seismic antenna at Merapi volcano” (EGU2020-19068)

16:40 Falcin et al.: “Automatic classification of seismo-volcanic signals at La Soufrière of Guadeloupe” (EGU2020-10234)

16:45 Lamb et al.: “Identifying icequakes at ice-covered volcanoes in Southern Chile” (EGU2020-851)

16:50 Battaglia et al.: “Discriminating icequakes from volcanic seismicity at Cotopaxi volcano (Ecuador) “ (EGU2020-11749)

16:55 Garza-Giron et al.: “Hidden earthquakes unveil the dynamic evolution of a large-scale explosive eruption “ (EGU2020-14124)

17:00 Shapiro et al.: "Degassing of volatile-reach basaltic magmas: source of deep long period volcanic earthquakes" (EGU2020-8251)

17:05 Cesca et al.: “The seismic sound of deep volcanic processes”, (EGU2020-6813)

17:10 Sadeghi and Suzuki: “The 11 November 2018 Mayotte event was observed at the Iranian Broadband seismic stations” (EGU2020-9767)

17:15 Ikegaya and Yamamoto: “Spatio-temporal characteristics and focal mechanisms of deep low-frequency earthquakes beneath Zao volcano, Japan”, (EGU2020-12533)

17:20 Möllhoff et al.: “Recent microseismicity observed at Hekla volcano and first velocity inversion results” (EGU2020-18954)

17:25 Bjarnasson et al. (presenting Revathy Parameswaran): “Interseismic stress field variations in Hjalli-Ölfus, SW Iceland” (EGU2020-8521)

17:30 Eibl et al.: “Seismic Eruption Catalog of Strokkur Geyser, Iceland“ (EGU2020-16535)

17:35 Thorbjarnardóttir et al.: “The Great Geysir and tectonic interactions in South Iceland”, (EGU2020-16388)

17:40 Nooshiri et al.: “Source mechanisms of seismic events during the 2018 eruption of Sierra Negra Volcano (Galapagos) determined by using polarization properties of complete (near-field and far-field) body waves”, (EGU2020-11297)

17:45 Longobardi,et al.: “Multiplet Based Time Lapse Velocity Changes Prior to the 2018 Eruption of Sierra Negra Volcano, Galapagos Island Observed with Coda Wave Interferometry” (EGU2020-18213)

17:50 Ka Lok Li et al.: “Different mechanisms of the pre- and co-eruptive tremor during the 2018 eruption at Sierra Negra volcano, Galapagos” (EGU2020-18975)

17:55 Dehghanniri and Jellinek: “An Experimental Study of Volcanic Tremor Driven by Magma Wagging” (EGU2020-11365)



FORMAT OF THE SESSION: Each author will present her/his work by highlighting the main points (ideally copy/paste). Please do it in a short summary. This will be followed by questions and discussion. The length of the individual slot (including questions) is 5 minutes.

In recent years, attention was paid to the detection and monitoring of volcanic ash clouds as their impact on the air traffic control system was unprecedented. Volcanic clouds are dangerous for the aviation as they can cause damage of the aircraft systems and engines not only close to active volcanoes but also at large distance from the eruption.
The intensity of the extreme convective events is supposed to increase worldwide due to the climate change and they can also cause large damages and affect air safety.

The recent Anak Krakatau, Raikoke and Ulawun eruptions highlighted the issue on different techniques to distinguish volcanic ash clouds from convective clouds, and the unsolved problem to understand if the cloud top is tropospheric or stratospheric.

The “extreme clouds” detection and estimation of their physical parameters is a highly multidisciplinary and challenging topic since the same techniques and instruments can be used for meteorology, volcanic monitoring, atmospheric physics and climate purposes. There is an urgent need to develop new techniques and instruments for monitoring, detecting and modeling “extreme clouds” to develop early warning systems and to support users, decision makers and policy makers.

This session solicits the latest studies from the spectrum of:
- Volcanic and Convective Clouds (CVC) remote sensing, detection, monitoring, modeling, forecasting and nowcasting
- understanding of CVC structure, including overshooting and ice clouds
- understanding the impact of CVC on climate changes and air safety
- proposal of new products or services focused on the end-users prospective (air traffic management and air safety)
- discussion on the recent Anak Krakatau, Raikoke and Ulawun eruptions

By considering studies over this range of topics we aim to identify new methods, detail current challenges, understand common techniques/methods and identify common discussions within the communities of atmospheric physicists, meteorologists, modelers, air traffic managers, pilots sensors engineers and engines manufacturers.

We particularly welcome and encourage contributions connecting different fields such as:
- forecasting tools to support air traffic management improving the limits of the present science and new products/tools providing better services to the end-users,
- extreme clouds remote sensing with novel techniques and new sensors,
- novel techniques to detect overshooting and their impact on climate.

Environmental systems often span spatial and temporal scales covering different orders of magnitude. The session is oriented in collecting studies relevant to understand multiscale aspects of these systems and in proposing adequate multi-platform and inter-disciplinary surveillance networks monitoring tools systems. It is especially aimed to emphasize the interaction between environmental processes occurring at different scales. In particular, a special attention is devoted to the studies focused on the development of new techniques and integrated instrumentation for multiscale monitoring high natural risk areas, such as: volcanic, seismic, energy exploitation, slope instability, floods, coastal instability, climate changes and other environmental context.
We expect contributions derived from several disciplines, such as applied geophysics, geology, seismology, geodesy, geochemistry, remote and proximal sensing, volcanology, geotechnical, soil science, marine geology, oceanography, climatology and meteorology. In this context, the contributions in analytical and numerical modeling of geological and environmental processes are also expected.
Finally, we stress that the inter-disciplinary studies that highlight the multiscale properties of natural processes analyzed and monitored by using several methodologies are welcome.

In tectonic and volcanic regions earthquake swarms and seismic sequences are frequently characterized by complex temporal evolution, and a delayed occurrence of the largest magnitude earthquakes. The complex evolution of such seismic sequences is generally considered to derive from transient forcing where fluids play a major role causing slow-slip and creeping events, and – at volcanoes – stresses due to magma migration (i.e. dike intrusion and pressurization of the magma plumbing system). Yet, the mechanisms of fluid-rock interaction, leading to changes of the rheological properties of faults, and of the fracture mechanics, are still far beyond a full understanding. Therefore, it is fundamental to develop and implement innovative methodologies and technologies or to apply multi-disciplinary approaches for a multi-parametric crustal imaging aimed at tracking fluid movements and/or pore fluid-pressure diffusion within the seismogenic crust, and to integrate the results with the analysis of spatio-temporal and size characteristics of earthquake occurrence. The two approaches complement each other improving, on one hand, our understanding of crustal properties and, on the other hand, help constraining the degree of involvement of fluids by the analysis of the earthquake statistics.
This session aims at putting together studies of swarms and complex seismic sequences modulated by aseismic transient forcing as well as field studies, numerical modeling, theoretical and experimental investigation on the detection and tracking of crustal fluids in tectonic, volcanic and industrial contexts. Contributions from multi-disciplinary studies of fluid geochemistry, surface ground deformation and space-time variations of electrical and seismic crustal properties are also welcome, as well as laboratory and numerical modeling simulating the mechanical condition yielding to fluid-driven swarm-like and complex seismic sequences.