Stephen R. J. Sparks

University of Bristol

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M. Paulatto

Imperial College London

C. Peirce

Durham University

Haraldur Sigurdsson

University of Rhode Island

S. M. Dean

National Institute of Water and Atmospheric Research

C. L. Kenedi

T. A. Minshull

National Oceanography Centre

Brian Baptie

British Geological Survey

J. O. S. Hammond

Birkbeck, University of London

E. Shalev

Duke University

T. Henstock

National Oceanography Centre

Cooperative Institutions

University of Southampton

University of Bristol

Centre National de la Recherche Scientifique

National Oceanography Centre

Montserrat Volcano Observatory

Istituto Nazionale di Geofisica e Vulcanologia

University of Cambridge

Cabot (United States)

University of Oxford

University of Auckland

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Lateral magma flow within rifted Icelandic crust

Nature (1978)

Haraldur Sigurdsson Stephen R. J. Sparks

Caldera

Icelandic

Magma chamber

10.1038/274126a0

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Citations (177)

Crustal structure of Montserrat and Surrounding Area From Integrated Onshore, Ocean Bottom and Multichannel Reflection Seismic Data

AGU Fall Meeting Abstracts (2008)

T. A. Minshull M. Paulatto Brian Baptie S. M. Dean J. O. S. Hammond

Reflection

Ocean bottom

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Palaeomagnetic determination of emplacement temperature of Vesuvius AD 79 pyroclastic deposits

Nature (1981)

Dennis V. Kent D. Ninkovich T. Pescatore Stephen R. J. Sparks

Pyroclastic fall

Breccia

10.1038/290393a0

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Citations (92)

Magma mixing: a mechanism for triggering acid explosive eruptions

Nature (1977)

Stephen R. J. Sparks Haraldur Sigurdsson L. Wilson

Magma chamber

Peléan eruption

Igneous differentiation

Vulcanian eruption

Phreatic eruption

10.1038/267315a0

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Citations (777)

Scenario-based tsunami hazard assessment at Kolumbo volcano

Research Square (Research Square) (2025)

Alessandro Tadini Matteo Cerminara Raphaël Paris Augusto Neri Stephen R. J. Sparks

Abstract Volcanic-induced tsunamis have a potentially devastating impact, especially in densely populated and/or touristic coastal areas. Kolumbo submarine volcano (Greece) experienced in 1650 CE an explosive eruption with eyewitnesses’ accounts of major tsunamis along the coasts of Santorini (Thera) and other islands. We present a scenario-based tsunami hazard assessment at this volcano based on existing simulations from literature and new simulations of tsunamis triggered by a less investigated but important mechanism, i.e. submarine landslides on the volcano flanks or within its crater. Simulations results show that the remobilization of a landslide volume of 150–300 Mm³ inside the crater can produce tsunami waves larger than 10 m high along the NE coast of Thera and of the order of 5 m along the E and SE coasts. The expected tsunami arrival time ranges from 2–3 minutes along the NE coast of Thera up to 8–10 min on its SE coast. Such scenarios produce inundation areas consistent with those reconstructed for the 1650 CE event, and tsunami waves propagating inland at velocities from 2 to 12 m/s. Simulation results also suggest that, given the landslide parameters assumed, it is unlikely to mobilize a landslide with a large volume from the SW-facing Kolumbo crater slopes, given the relatively gentle topo-bathymetry of this area. The study findings are relevant based on the outcomes of the expert elicitation exercise carried out in parallel, which indicate that chances of having waves larger than 1 m high on the NE coast of Thera have median probabilities of 50–60%.

Volcanic hazards

10.21203/rs.3.rs-5700315/v1

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Seismic Velocity Structure of the Island of Montserrat From Reflection/Refraction Tomography

AGUFM (2008)

M. Paulatto T. A. Minshull Brian Baptie S. M. Dean J. O. S. Hammond

Reflection

Source

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Retrospective analysis of uncertain eruption precursors at La Soufrière volcano, Guadeloupe, 1975–77: volcanic hazard assessment using a Bayesian Belief Network approach

Journal of Applied Volcanology (2014)

Thea Hincks Jean‐Christophe Komorowski Stephen R. J. Sparks Willy Aspinall

Scientists monitoring active volcanoes are increasingly required to provide decision support to civil authorities during periods of unrest. As the extent and resolution of monitoring improves, the process of jointly interpreting multiple strands of indirect evidence becomes increasingly complex. Similarities with uncertainties in medical diagnosis suggest a formal evidence-based approach, whereby monitoring data are analysed synoptically to provide probabilistic hazard forecasts. A statistical tool to formalize such inferences is the Bayesian Belief Network (BBN). By explicitly representing conditional dependencies between the volcanological model and observations, BBNs use probability theory to treat uncertainties in a rational and auditable manner, as warranted by the strength of the scientific evidence. A retrospective analysis is given for the 1976 Guadeloupe crisis, using a BBN to provide inferential assessment of the state of the evolving magmatic system and probability of incipient eruption. Conditional dependencies are characterized quantitatively by structured expert elicitation. Analysis of the available monitoring data suggests that at the height of the crisis the probability of magmatic intrusion was high, in accordance with scientific thinking at the time. The corresponding probability of magmatic eruption was elevated in July and August 1976 and signs of precursory activity were justifiably cause for concern. However, collective uncertainty about the future course of the crisis was also substantial. Of all the possible scenarios, the most likely outcome evinced by interpretation of observations on 31 August 1976 was 'no eruption' (mean probability 0.5); the chance of a magmatic eruption/blast had an estimated mean probability of ~0.4. There was therefore no evidential basis for asserting one scenario to be significantly more likely than another. Our analysis adds objective probabilistic expression to the volcanological narrative at the time of the 1976 crisis, and demonstrates that a formal evidential case could have supported the authorities' concerns about public safety and decision to evacuate. Revisiting the episode highlights many challenges for modern, contemporary decision making under conditions of considerable uncertainty, and suggests the BBN is a suitable framework for marshalling multiple, uncertain observations, model results and interpretations. The formulation presented here can be developed as a tool for ongoing use in the volcano observatory.

Conditional probability

Unrest

10.1186/2191-5040-3-3

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Citations (117)

Global recording rates for large eruptions

Journal of Applied Volcanology (2016)

J Rougier Stephen R. J. Sparks K. V. Cashman

A non-parametric statistical approach is used to assess the global recording rate for large (M4+) stratovolcano eruptions in a modern database, LaMEVE (v3.1). This approach imposes minimal structure on the shape of the recording rate through time. We find that recording rates have declined rapidly, going backwards in time. Prior to the year 1600 they are below 50 %, and prior to 1100 they are below 20 %. Even in the recent past, e.g. the 1800s, they are likely to be less than 100 %. The assessment for very large (M5+) eruptions is more uncertain, due to the scarcity of events.

Stratovolcano

10.1186/s13617-016-0051-4

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Citations (34)