Our team will be presenting research at the upcoming International Association of Volcanology and Chemistry of the Earth's Interior (IAVCEI) General Assembly in Geneva. Below are the abstracts that will be shared.
IAVCEI 2025
FEVER: Forecasting Eruptions at Volcanoes after Extended Repose
Christopher Kilburn (1,5), Eric Newland (1), Matias Clunes (2), Carmen Solana (2), Philip Benson (1), Erouscilla Joseph (3), Giuseppe De Natale (4)
1. UCL Hazard Centre, Department of Earth Sciences, UCL, London, UK; 2. School of the Environment and Life Sciences, University of Portsmouth, Portsmouth, UK; 3. Seismic Research Centre, University of the West Indies, Trinidad and Tobago; 4. INGV-Sezione di Napoli, Osservatorio Vesuviano, Napoli, Italy
Volcanic unrest is often described as complex and highly variable, especially after a volcano has remained several centuries in repose. The description may be convenient for managing expectations about the ability to forecast eruptions, but risks promoting a mind-set that volcanic systems are too complicated to follow a shared set of pre-eruptive trends. It is also popular to apply statistical methods on a case-by-case basis to identify combinations of behaviour that may signal an eruption. The results are empirical and cannot be transferred from one volcano to another. Project FEVER takes the opposite view; that patterns of unrest can be interpreted in terms of deterministic processes and transferable between volcanoes. At volcanoes restless after extended repose, for example, magma must break open a pathway through the crust before it erupts. The fundamental mechanics of crustal rupture occurs under restricted ranges of physical conditions and these, in turn, promote repeatable and quantifiable patterns of deformation and fracture. Our philosophy is supported by new laboratory and theoretical studies of rock failure in extension. They reveal that accelerating rates of seismicity observed before eruption are consistent with progressive strain softening in crust being stretched above a zone of increasing pressure (e.g., of magma or high-temperature fluids). The rate of softening can be quantified to constrain forecasts of rupture. It has thus the potential to enhance operational procedures – and we will test its performance through integrating our objective, physics-based criteria into current forecasting procedures that rely on probabilistic analysis.
Temporal Evolution of Crustal Stress and Seismicity at Volcanoes During Periods of Unrest
Eric Newland (1, 2), Christopher Kilburn (1, 2)
1. UCL Hazard Centre, Department of Earth Sciences, UCL, London, UK; 2. Project FEVER, UKRI, UK.
Eruptions that occur at volcanoes after periods of quiescence are difficult to forecast. Pathways that connect the source to the surface may have become sealed. The pressurisation of the source leads to the deformation of the crust. Initially the crust deforms elastically, strain is accommodated via ground movement and elastic strain energy is stored to the crust. Then, the deformation transitions to inelastic where strain is accommodated via brittle failure (volcano-tectonic event), and elastic strain energy is transferred from the crust. We present a novel method to estimate the temporal evolution of elastic strain energy and bulk stress during periods of unrest. We consider the transfer of energy using measurements of surface deformation and seismic activity. We evaluate the temporal evolution of crustal bulk stress and investigate the progression of deformation in the crust. We apply our method to the unrest at the Campi Flegrei caldera, Italy from 2011-2024. Our calculations reveal that the bulk stress follows a characteristic progression, in which the stress initially increases linearly with time prior to the onset of significant seismicity, consistent with elastic deformation. We then observe a transition to inelastic deformation, when rate of elastic strain energy lost via fracturing increases and eventually exceeds the rate of elastic strain energy transferred to the crust. This results in a decrease in the bulk stress stored in the crust with time. Comparison with laboratory experiments show the behaviour is consistent with bulk failure in extension and the potential formation of new pathways in the crust.
Progress in anticipating crustal rupture during unrest at Campi Flegrei
Christopher Kilburn (1, 5), Eric Newland (1, 5), Nicola Alessandro Pino (2), Stefano Carlino (3), Stefania Danesi (4)
1. UCL Hazard Centre, Department of Earth Sciences, UCL, London, UK; 2. Università di Camerino, Scuola di Scienze e Tecnologie, Sezione di Geologia, Camerino, Italy; 3. INGV-Sezione di Napoli, Osservatorio Vesuviano, Napoli, Italy; 4. INGV-Sezione di Bologna, Bologna, Italy; 5. Project FEVER, UKRI, UK.
The 2017-2024 volcano-tectonic (VT) crisis at Campi Flegrei has provided a remarkable dataset for relating changes in VT seismicity with time to the progress of crustal rupture. The rate of VT seismicity passed through four stages until early 2024: an exponential increase in 2017-2020, a constant rate in 2020-2022, a hyperbolic increase until November 2023 and a three-month decay until March 2024. The sequence was followed by a rapid increase in rate to the highest recorded value in April 2024, since when it has been in gentle decline. Throughout the sequence, the floor of the caldera was uplifted at rates of 1-2 cm a month in the zone of fastest movement. An energy balance between uplift and seismicity reveals an accumulation of stress until 2022 and a decrease thereafter. The highest VT event rates thus occurred while stress was being lost. Such a relation is counter-intuitive, because decreasing stress is commonly associated with an Omori-style decline in VT event rate while crust relaxes. We attribute the increase in event rate to a self-accelerated interlinking of fractures that, more speculatively, triggered a temporary redistribution of pore fluids in the zone of nascent rupture, resulting in the brief decrease in seismicity in late 2023-early 2024. If confirmed, our interpretation suggests that Campi Flegrei’s crust today contains a major new discontinuity – that is, a structural weakness now available to be exploited by magma or magmatic fluids during future episodes of uplift.
Progress in anticipating crustal rupture during unrest at Campi Flegrei
Christopher Kilburn (1, 5), Eric Newland (1, 5), Nicola Alessandro Pino (2), Stefano Carlino (3), Stefania Danesi (4)
1. UCL Hazard Centre, Department of Earth Sciences, UCL, London, UK; 2. Università di Camerino, Scuola di Scienze e Tecnologie, Sezione di Geologia, Camerino, Italy; 3. INGV-Sezione di Napoli, Osservatorio Vesuviano, Napoli, Italy; 4. INGV-Sezione di Bologna, Bologna, Italy; 5. Project FEVER, UKRI, UK.
The 2017-2024 volcano-tectonic (VT) crisis at Campi Flegrei has provided a remarkable dataset for relating changes in VT seismicity with time to the progress of crustal rupture. The rate of VT seismicity passed through four stages until early 2024: an exponential increase in 2017-2020, a constant rate in 2020-2022, a hyperbolic increase until November 2023 and a three-month decay until March 2024. The sequence was followed by a rapid increase in rate to the highest recorded value in April 2024, since when it has been in gentle decline. Throughout the sequence, the floor of the caldera was uplifted at rates of 1-2 cm a month in the zone of fastest movement. An energy balance between uplift and seismicity reveals an accumulation of stress until 2022 and a decrease thereafter. The highest VT event rates thus occurred while stress was being lost. Such a relation is counter-intuitive, because decreasing stress is commonly associated with an Omori-style decline in VT event rate while crust relaxes. We attribute the increase in event rate to a self-accelerated interlinking of fractures that, more speculatively, triggered a temporary redistribution of pore fluids in the zone of nascent rupture, resulting in the brief decrease in seismicity in late 2023-early 2024. If confirmed, our interpretation suggests that Campi Flegrei’s crust today contains a major new discontinuity – that is, a structural weakness now available to be exploited by magma or magmatic fluids during future episodes of uplift.
Theory and reality in adopting best-practice guidelines during a volcanic crisis
Christopher Kilburn (1), Stefano Carlino (2), Nicola Alessandro Pino (3)
1. UCL Hazard Centre, Department of Earth Sciences, UCL, London, UK; 2. INGV-Sezione di Napoli, Osservatorio Vesuviano, Napoli, Italy; 3. Università di Camerino, Scuola di Scienze e Tecnologie, Sezione di Geologia, Camerino, Italy
Guidelines to recommended best practice during volcanic emergencies are easy to support on paper, but less so when an emergency strikes – particularly if this occurs after a lull of several decades. Such intervals are long enough to forget the lessons from previous crises. When a new crisis develops, therefore, individuals may not automatically follow the recommendations, especially if responding to an emergency for the first time. The first crisis at Campi Flegrei in four decades provides a topical case study. West of Naples in Italy, the volcano is home to more than 360,000 people. Following intense volcanotectonic seismicity in September-October 2023, a report on 09 November in southern Italy’s leading newspaper, Il Mattino, cited the opinions of “anonymous volcanologists”, who claimed that selected (and peer-reviewed) analyses recently presented to Italy’s Major Risk Committee were “ based on fundamental errors” and “incorrect data” and that they were the results of models – which are “only theories and [often] wrong”. The claimants had “not been present at the meeting”. They also offered no evidence to justify their criticisms. A predictable outcome was the corrosion of public trust in scientific information. Even if the criticisms were well-intentioned and the consequences of media engagement unexpected, the lack of supporting evidence meant that opportunities were missed for enhancing the collective interpretation of the volcano’s unrest. Moral imperatives for scientists during crises are thus not only to be careful in communicating with non-scientists, but also to engage in the constructive testing of ideas among colleagues.
Our team’s research was presented at the American Geophysical Union (AGU) Annual Meeting 2024. Below are the abstracts of the work we shared.
AGU 2024
Temporal Evolution of Crustal Stress at Volcanoes: Unrest at Campi Flegrei caldera, 2011-present
Eric Newland (1, 2), Christopher Kilburn (1, 2)
1. UCL Hazard Centre, Department of Earth Sciences, UCL, London, UK; 2. Project FEVER, UKRI, UK.
We present a novel method to monitor the temporal evolution of stress within a volcanic system and so estimate its potential to rupture before an eruption. Volcanoes quiescent for centuries seal their connections in the crust between magma and the surface. Before another eruption, they must rupture a new pathway for magma ascent. Precursory unrest yields characteristic accelerations in volcano-tectonic (VT) event rate with time as the dominant mode of deformation evolves from the elastic stretching of unbroken rock with minor faulting (quasi-elastic behaviour) to brittle fracture and fault slip (inelastic behaviour). The trends indirectly measure changes in stress. However, their specific form is sensitive to the magnitudes of VT events, so that event rate alone can yield ambiguous forecasts of rupture. We used the remarkable data from the INGV-Osservatorio Vesuviano for the 2004-present unrest at Campi Flegrei to compare the VT time series against independent estimates of stress. From the magnitude and distribution of surface deformation prior to significant seismicity in 2017, we define the region in which strain energy is concentrated around a deforming source and quantified the rate of stress being supplied to this region. We calculated the rate of stress loss from the elastic strain energy released by VT seismicity. The difference between the estimates gave the mean stress in the volume of crust being deformed. Our results show a progression in stress from a linear increase with time before 2017, after which it increased at a decelerating rate (quasi-elastic regime) and, following a near constant value in 2021-2022, decreased at an accelerating rate in 2023 (inelastic regime). The changes in stress coincide with changes in VT event rate. Unexpectedly, they show that the inelastic acceleration in VT event rate occurred while the stress decreased. We attribute this apparent contradiction to an increase in the number of larger VT events and a concentration of major fracturing within a decreasing volume.
Key Publications
Below is a selection of key publications from our team.
Kilburn, C. R. J. (2018) Forecasting volcanic eruptions: beyond the failure forecast method. Front. Earth Sci. 6, 133
Kilburn, C. R. J. (2012). Precursory deformation and fracture before brittle rock failure and potential application to volcanic unrest. J. Geophys. Res. 117:B02211. doi: 10.1029/2011JB008703
Gehne, S., Forbes Inskip, N. D., Benson, P. M., Meredith, P. G., & Koor, N. (2020). Fluid-driven tensile fracture and fracture toughness in Nash Point shale at elevated pressure. JGR: Solid Earth,125.
Kilburn, C. R., De Natale, G., & Carlino, S. (2017). Progressive approach to eruption at Campi Flegrei caldera in southern Italy. Nature Communications, 8(1), 1-8.
Robertson, R. E., Barclay, J., Joseph, E. P., & Sparks, R. S. J. (2024). An overview of the eruption of La Soufrière Volcano, St Vincent 2020–21. Geological Society, London, Special Publications, 539(1), 1-24.
Solana, C., & Kilburn, C. R. (2022). Translating research into operational procedures for reducing the risk from volcanic eruptions. Bulletin of Volcanology, 84(6), 56.
Kilburn, C. R. J. (2003). Multiscale fracturing as a key to forecasting volcanic eruptions. J. Volcanol. Geotherm. Res. 125, 271–289. doi: 10.1016/S0377- 0273(03)00117-3 K
Benson, P. M., Vinciguerra, S., Meredith, P. G., and Young R. P., (2008) Laboratory Simulation of Volcano Seismicity, Science, 322,249 252(2008). DOI:10.1126/science.1161927
De Natale, G., Troise, C., & Somma, R. (2020). Invited perspectives: The volcanoes of Naples: how can the highest volcanic risk in the world be effectively mitigated?. Natural Hazards and Earth System Sciences, 20(7), 2037-2053.
Joseph, E. P., Camejo-Harry, M., Christopher, T., Contreras-Arratia, R., Edwards, S., ... & Sparks, R. S. J. (2022). Responding to eruptive transitions during the 2020–2021 eruption of La Soufrière volcano, St. Vincent. Nature Communications, 13(1), 4129.
Joseph, E. P., Jackson, V. B., Beckles, D. M., Cox, L., & Edwards, S. (2019). A citizen science approach for monitoring volcanic emissions and promoting volcanic hazard awareness at Sulphur Springs, Saint Lucia in the Lesser Antilles arc. Journal of Volcanology and Geothermal Research, 369, 50-63.
Solana, M. C., Calvari, S., Kilburn, C. R. J., Gutierrez, H., Chester, D., & Duncan, A. (2018). Supporting the development of procedures for communications during volcanic emergencies: lessons learnt from the Canary Islands (Spain) and Etna and Stromboli (Italy). Observing the Volcano World: Volcano Crisis Communication, 289-305.