About

Helge Gonnermann is a Professor in the Department of Earth, Environmental and Planetary Sciences at Rice University. His main research focus is on magmatic and volcanic processes, aiming to better understand phenomena ranging from micro-scale bubble nucleation in magmas to field-scale magma flow and accumulation leading to volcanic eruptions. His research group works on analyzing observational data, conducting laboratory experiments, and applying numerical modeling techniques to gain insights into volcanic activity and magmatic dynamics. Gonnermann's work emphasizes the physics of bubble nucleation, growth, coalescence, and rupture during magma ascent, which largely controls eruptive style and intensity. He studies how volatile content in magmas influences buoyancy and eruption behavior, and investigates the long-term evolution and deformation of volcanoes, magma accumulation and ascent processes, and interactions between volcanoes. His geodynamics research includes exploring the structure and evolution of the Earth's mantle, integrating geochemical observations with thermal convection models to understand Earth's thermal and volatile evolution. In addition to his research, Gonnermann teaches a Geological Field Methods course in New Mexico, focusing on the transition between the Rio Grande Rift and the Colorado Plateau. He is involved in developing projects that study geodynamics, volcanology, and landscape evolution, contributing to the understanding of Earth's geological processes.

Selected publications

• Identifying rheological regimes within pyroclastic density currents

  Nature Communications · 2024-05-23 · 7 citations

  articleOpen accessSenior author

  Pyroclastic density currents (PDCs) are the most lethal of all volcanic hazards. An ongoing challenge is to accurately forecast their run-out distance such that effective mitigation strategies can be implemented. Central to this goal is an understanding of the flow mobility-a quantitative rheological model detailing how the high temperature gas-pyroclast mixtures propagate. This is currently unknown, yet critical to accurately forecast the run-out distance. Here, we use a laboratory apparatus to perform rheological measurements on real gas-pyroclast mixtures at dynamic conditions found in concentrated to intermediate pumice-rich PDCs. We find their rheology to be non-Newtonian featuring (i) a yield stress where deposition occurs; (ii) shear-thinning behavior that promotes channel formation and local increases in velocity and (iii) shear-thickening behavior that promotes decoupling and potential co-PDC plume formation. We provide a universal regime diagram delineating these behaviors and illustrating how flow can transition between them during transport.

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• Feasibility of melt segregation from a crystal mush in response to the 2011–2012 eruption at Cordón Caulle, Chile

  Geophysical Journal International · 2023-05-27 · 7 citations

  articleOpen access

  SUMMARY The 2011–2012 eruption at Cordón Caulle in Chile produced crystal-poor rhyolitic magma with crystal-rich mafic enclaves whose interstitial glass is of identical composition to the host rhyolite. Eruptible rhyolites are thought to be genetically associated with crystal-rich magma mushes, and the enclaves within the Cordón Caulle rhyolite support the existence of a magma mush from which the erupted magma was derived. Moreover, towards the end of the 2011–2012 eruption, subsidence gave way to inflation that has on average been continuous through at least 2020. We hypothesize that magma segregation from a crystal mush could be the source of the observed inflation. Conceptually, magma withdrawal from a crystal-poor rhyolite reservoir caused its depressurization, which could have led to upward flow of interstitial melt within an underlying crystal mush, causing a new batch of magma to segregate and partially recharge the crystal-poor rhyolite body. Because the compressibility of the crystalline matrix of the mush is expected to be lower than that of the interstitial melt, which likely contains some fraction of volatile bubbles, this redistribution of melt would result in a net increase in volume of the system and in the observed inflation. We use numerical modelling of subsurface magma flow and storage to show under which conditions such a scenario is supported by geodetic and petrologic observations.

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• Insights for crystal mush storage utilizing mafic enclaves from the 2011-12 Cordón Caulle eruption

  Research Square · 2022-02-24 · 2 citations

  preprintOpen access

  Abstract Two distinct types of rare crystal-rich mafic enclaves have been identified in the rhyolite lava flow from the 2011-12 Cordón Caulle eruption (Southern Andean Volcanic Zone, SVZ). The majority of mafic enclaves are coarsely crystalline with interlocking olivine-clinopyroxene-plagioclase textures and irregular shaped vesicles filling the crystal framework. These enclaves are interpreted as pieces of crystal-rich magma mush underlying a crystal-poor rhyolitic magma body that has fed recent silicic eruptions at Cordón Caulle. A second type of porphyritic enclaves, with restricted mineral chemistry and spherical vesicles, represents small-volume injections into the rhyolite magma. Both types of enclaves are basaltic endmembers (up to 9.3 wt% MgO and 50-53 wt% SiO 2 ) in comparison to enclaves erupted globally. The Cordón Caulle enclaves also have one of the largest compositional gaps on record between the basaltic enclaves and the rhyolite host at 17 wt% SiO 2 . Interstitial melt in the coarsely-crystalline enclaves is compositionally identical to their rhyolitic host, suggesting that the crystal-poor rhyolite magma was derived directly from the underlying basaltic magma mush through efficient melt extraction. We suggest the 2011-12 rhyolitic eruption was generated from a primitive basaltic crystal-rich mush that short-circuited the typical full range of magmatic differentiation in a single step.

  PublisherOA PDFDOI

• Outgassing through magmatic fractures enables effusive eruption of silicic magma

  Journal of Volcanology and Geothermal Research · 2022-07-14 · 19 citations

  articleOpen access

  Several mechanisms have been proposed to allow highly viscous silicic magma to outgas efficiently enough to erupt effusively. There is increasing evidence that challenges the classic foam-collapse model in which gas escapes through permeable bubble networks, and instead suggests that magmatic fracturing and/or accompanying localized fragmentation and welding within the conduit play an important role in outgassing. The 2011–2012 eruption at Cordón Caulle volcano, Chile, provides direct observations of the role of magmatic fractures. This eruption exhibited a months-long hybrid phase, in which rhyolitic lava extrusion was accompanied by vigorous gas-and-tephra venting through fractures in the lava dome surface. Some of these fractures were preserved as tuffisites (tephra-filled veins) in erupted lava and bombs. We integrate constraints from petrologic analyses of erupted products and video analyses of gas-and-tephra venting to construct a model for magma ascent in a conduit. The one-dimensional, two-phase, steady-state model considers outgassing through deforming permeable bubble networks, magmatic fractures, and adjacent wall rock. Simulations for a range of plausible magma ascent conditions indicate that the eruption of low-porosity lava observed at Cordón Caulle volcano occurs because of significant gas flux through fracture networks in the upper conduit. This modeling emphasizes the important role that outgassing through magmatic fractures plays in sustaining effusive or hybrid eruptions of silicic magma and in facilitating explosive-effusive transitions.

  PublisherDOI

• Quantifying the Water‐to‐Melt Mass Ratio and Its Impact on Eruption Plumes During Explosive Hydromagmatic Eruptions

  Geochemistry Geophysics Geosystems · 2022-02-01 · 14 citations

  articleOpen access

  Abstract The interaction of magma with external water commonly enhances magma fragmentation through the conversion of thermal to mechanical energy and results in an increased production of fine‐grained volcanic tephra. Magma‐water interaction is thus of importance for hazard mitigation on both a local and a regional scales. The relative proportion of water that interacts with magma, quantified as the water‐to‐melt mass ratio, is thought to determine the efficiency of thermal to mechanical energy conversion, termed the fragmentation efficiency. Here, we analyze the pyroclast size distributions from the 10th century Eldgjá fissure eruption in Iceland, where parts of the fissure erupted subglacially and other erupted subaerially. The subglacially erupted magma passed through a column of glacial meltwater, resulting in a larger proportion of finer pyroclast sizes relative to the subaerially erupted, purely magmatic tephra. This finer grain size distribution has been attributed to quench‐granulation induced by enhanced cooling upon interaction with external water. We hypothesize that the additional fragmentation (surface) energy required to produce the finer grained hydromagmatic deposits is due to the conversion of thermal to mechanical energy associated with the entrainment of water into the volcanic jet, as it passed through a column of subglacial melt water. Based on field and granulometry data, we estimate that the interaction of the volcanic jet with the meltwater provided an additional fragmentation energy of approximately 3–14 kJ per kg of pyroclasts. We numerically model the hydrofragmentation energy within a jet that passes through a layer of meltwater. We find that the water‐to‐melt mass ratio of entrained water required to produce the additional fragmentation energy is in the range of 1–2, which requires a minimum ice melting rate of 10 4 m 3 s −1 . Our simulation results show that the water‐to‐melt ratio is an important parameter that controls the ascent of plume in the atmosphere.

  PublisherOA PDFDOI

• Insights for crystal mush storage utilizing mafic enclaves from the 2011–12 Cordón Caulle eruption

  Scientific Reports · 2022-06-13 · 21 citations

  articleOpen access

  Abstract Two distinct types of rare crystal-rich mafic enclaves have been identified in the rhyolite lava flow from the 2011–12 Cordón Caulle eruption (Southern Andean Volcanic Zone, SVZ). The majority of mafic enclaves are coarsely crystalline with interlocking olivine-clinopyroxene-plagioclase textures and irregular shaped vesicles filling the crystal framework. These enclaves are interpreted as pieces of crystal-rich magma mush underlying a crystal-poor rhyolitic magma body that has fed recent silicic eruptions at Cordón Caulle. A second type of porphyritic enclaves, with restricted mineral chemistry and spherical vesicles, represents small-volume injections into the rhyolite magma. Both types of enclaves are basaltic end-members (up to 9.3 wt% MgO and 50–53 wt% SiO 2 ) in comparison to enclaves erupted globally. The Cordón Caulle enclaves also have one of the largest compositional gaps on record between the basaltic enclaves and the rhyolite host at 17 wt% SiO 2 . Interstitial melt in the coarsely-crystalline enclaves is compositionally identical to their rhyolitic host, suggesting that the crystal-poor rhyolite magma was derived directly from the underlying basaltic magma mush through efficient melt extraction. We suggest the 2011–12 rhyolitic eruption was generated from a primitive basaltic crystal-rich mush that short-circuited the typical full range of magmatic differentiation in a single step.

  PublisherOA PDFDOI

• 3.5 Normativität in der TA

  Nomos Verlagsgesellschaft mbH & Co. KG eBooks · 2021-01-01 · 2 citations

  book-chapterSenior author

  The complexity of socio-technological challenges and the uncertainty of decisions are both increasing. Therefore, there is a need for knowledge-based and option-oriented assessment and advice. Technology assessment (TA) can offer alternative approaches to and perspectives on current decision-making processes. This handbook provides guidance in developing new answers to the problems under investigation. It pursues three objectives. Firstly, it reflects on TA by looking at developments in TA. Secondly, it serves as a compass for orientation by providing heuristics for the systematic contextualisation of TA knowledge. Thirdly and finally, it reveals the prospects for the future development of TA. With contributions by Suzana Alpsancar, Manuel Baumann, Richard Beecroft, Alexander Bogner, Stefan Böschen, Helmut Breitmeier, Andrés Checa, Kerstin Cuhls, Bert Droste-Franke, Elisabeth Ehrensperger, Torsten Fleischer, Antje Grobe, Armin Grunwald, Reinhard Grünwald, Martina Haase, Julia Hahn, Christiane Hauser, Roger Häußling, Leonhard Hennen, Nils Heyen, Regine Kollek, Kornelia Konrad, Jürgen Kopfmüller, Bettina-Johanna Krings, Miltos Ladikas, Roh Pin Lee, Annette Leßmöllmann, Peter Letmathe, Ralf Lindner, Andreas Lösch, Jacob Manderbach, Martin Meister, Linda Nierling, Maren Paegert, Oliver Parodi, Walter Peissl, Witold-Roger Poganietz, Christine Rösch, Maximilian Roßmann, Martin Sand, Jens Schippl, Jan C. Schmidt, Christoph Schneider, Jan-Felix Schrape, Ingo Schulz-Schaeffer, Sandra Schwindenhammer, Hans-Jörg Sigwart, Mahshid Sotoudeh, Magdalena Tanzer, Helge Torgesen, Peter Wehling, Christina Wulf, Petra Zapp and Silke Zimmer-Merkle.

  PublisherDOI

• Modeling Volcano-Magmatic Systems: Workshop Report for the Modeling Collaboratory for Subduction Research Coordination Network

  2021-11-12 · 1 citations

  preprintOpen access1st author

  This document summarizes the outcomes of the Modeling Collaboratory for Subduction Zone Science (MCS) Volcanic Systems Workshop and presents a vision for advancing collaborative modeling of volcano-magmatic systems. The U.S. Geological Survey (USGS) has identified 161 potentially active volcanoes in the United States and its territories, of which 57 are considered to be high or very high threats (Ewert et al., 2018). All western states, including Alaska and Hawaii, have potentially active volcanoes. Eruptions range from the quiet effusion of sluggish lava flows over hours to decades to immense explosive ejections of tephra which produce massive calderas.Understanding these volcanoes and assessing their threat to society requires the development of quantitative models, rooted in physics and chemistry, which can be used to interpret diverse observations including real-time monitoring data. Existing models have tremendously advanced our understanding of volcanic systems and have improved our ability to assess hazards and forecast future activity, contributing directly to reductions in the number of lives lost to volcanic eruptions and helping mitigate their costs to society. Magmatic system models also provide a quantitative framework for understanding processes that occur at depth beneath volcanoes, linking volcanic systems with a broad range of deeper processes associated with the production, transport, and storage of magma and associated fluids above subducting slabs.Despite this exciting progress much remains to be accomplished and workshop participants identified several important opportunities. First and foremost is the recognition that enhanced support for the development and dissemination of volcano-magmatic system models and associated methodologies will enable advances in ways not currently possible. A key outcome of the workshops is a recognition of the transformative potential of diverse groups of scientists working together on common problems. Support for collaborative working groups will enable communication across disciplines and between modelers and non-modelers, leveraging expertise from scientists studying different aspects of volcano-magmatic systems, and between geoscientists and outside experts from fields such as mathematics, statistics, and material sciences. Better support will also enable modelers to more fully verify, validate, benchmark, and document their codes, and also provide new training opportunities. Enhanced model sharing and interoperability will reduce the need for different groups to independently duplicate (re-invent) code and increase confidence in published results. This report lays out a proposal for a collaborative modeling environment that is centered in large part around community working groups manifested as workshops, summer schools, and sustained long-term research collaborations involving diverse groups of scientists working on common problems. Programmatic support is envisioned in the form of enhanced student and postdoc funding for model development, incentives and support for cross-disciplinary collaborative research projects, and related support for these activities. This support will fundamentally improve our ability to integrate and interpret observations using volcanic and magmatic system models.

  PublisherOA PDFDOI

• Reconciling bubble nucleation in explosive eruptions with geospeedometers

  Nature Communications · 2021-01-12 · 56 citations

  articleOpen access

  Magma from Plinian volcanic eruptions contains an extraordinarily large numbers of bubbles. Nucleation of those bubbles occurs because pressure decreases as magma rises to the surface. As a consequence, dissolved magmatic volatiles, such as water, become supersaturated and cause bubbles to nucleate. At the same time, diffusion of volatiles into existing bubbles reduces supersaturation, resulting in a dynamical feedback between rates of nucleation due to magma decompression and volatile diffusion. Because nucleation rate increases with supersaturation, bubble number density (BND) provides a proxy record of decompression rate, and hence the intensity of eruption dynamics. Using numerical modeling of bubble nucleation, we reconcile a long-standing discrepancy in decompression rate estimated from BND and independent geospeedometers. We demonstrate that BND provides a record of the time-averaged decompression rate that is consistent with independent geospeedometers, if bubble nucleation is heterogeneous and facilitated by magnetite crystals.

  PublisherOA PDFDOI

• Die Transformation der TA im Zuge der TA von Transformationen

  Nomos Verlagsgesellschaft mbH & Co. KG eBooks · 2021-01-01 · 1 citations

  book-chapterSenior author

  The intensively discussed term transformation refers to the comprehensive restructuring of processes and behaviour in order to address societal challenges posed by far-reaching changes in energy, transport, production and agricultural systems. Since such complex transformations are always accompanied by uncertainties about their effects and consequences, the contributions in this volume critically examine the opportunities and risks involved in these processes and discuss the possibilities and limits of technology assessment in the context of societal transformations. The volume brings together the academic contributions to the 8th international conference of the Technology Assessment Network, which took place in Karlsruhe from 7th to 8th November 2018. With contributions by Fabian Adelt, Marius Albiez, Annika Arnold, Walaa Bashary, Anja Bauer, Richard Beecroft, Alexander Bogner, Stefan Böschen, Tanja Bratan, Simone Colombo, Michael Decker, Rico Defila, Antonietta Di Giulio, Marion Dreyer, Elisabeth Ehrensperger, Philipp Ellett, Lorenz Erdmann, Ali Abdelshafy Ezzat, Erik Fisher, Michael Friedewald, Livia Fritz, Daniela Fuchs, Maryegli Fuss, Armin Grunwald, Niklas Gudowsky, Kristin Hagen, Simeon Hassemer, Alexandra Hausstein, Nils B. Heyen, Diego Iván Hidalgo Rodriguez, Peter Hocke, Florian Hoffmann, Sebastian Hoffmann, Michael Jonas, Dorothee Keppler, Jeanette Klink-Lehmann, Hannah Kosow, Cordula Kropp, Sophie Kuppler, Bastian Lange, Wolfgang Liebert, Ralf Lindner, Stephan Lingner, Andreas Lösch, Maria Maia, Martin Nicholas, Melanie Mbah, Franziska Meinherz, Rolf Meyer, Johanna Myrzik, Lisa Nabitz, Linda Nierling, Oliver Parodi, Witold-Roger Poganietz, Carmen Priefer, Filippo Reale, Ernst Dieter Rossmann, André Schaffrin, Dirk Scheer, Constanze Scherz, Jan Cornelius Schmidt, Maike Schmidt, Flurina Schneider, Andreas Seebacher, Astrid Segert, Mahshid Sotoudeh, Helge Torgersen, Ulrich Ufer, Karsten Weber, Matthias Weber and Johannes Weyer.

  PublisherDOI