Christopher Kilburn

• Professor at UCL

Manam is one of the most frequently active volcanoes in Papua New Guinea and is a top contributor to global volcanic volatile emissions due to its persistent open-vent degassing. Here, we present a multi-year time series (2018–2021) of thermal and SO 2 emissions for Manam from satellite remote sensing, which we interpret in the context of open-vent...

Changes in seismicity with time and location are diagnostic signals for understanding the dynamics of volcanic unrest. We used these signals at the Campi Flegrei caldera, in southern Italy, to investigate how structural changes have determined three styles of unrest since 1982, distinguished by a ground uplift (measured at Pozzuoli, near the centre...

Volcanoes reawakening after long repose must rupture the crust before magma can erupt. Rupture is preceded by repeatable variations in the rate of seismicity with ground movement, which trace the amount of applied stress that is released by local earthquakes. A rupturing sequence has been developing across four episodes of ground uplift at Italy’s...

In this perspective piece, we reflect on scientific progress in volcanic risk reduction and its prospects for future development. In spite of recent advances, a dichotomy still exists between the products of academic research and the desire for practical applications. The main themes to emerge are (1) the need to find the most effective ways to exp...

Forecasts of eruption are uncertain. The uncertainty is amplified when volcanoes reawaken after several generations in repose, because direct evidence of previous behaviour is rarely available. It fosters scepticism about warnings of volcanic activity and may compromise the success of emergency procedures. The quality of forecasts has improved over...

One of the largest climate forcing eruptions of the nineteenth century was, until recently, believed to have taken place at the Babuyan Claro volcano, in the Philippines, in 1831. However, a recent investigation found no reliable evidence of such an eruption, suggesting that the 1831 eruption must have taken place elsewhere. We here present our new...

One of the largest climate forcing eruptions of the nineteenth century was, until recently, believed to have taken place at Babuyan Claro volcano, in the Philippines, in 1831. However, a recent investigation found no reliable evidence of such an eruption, suggesting that the 1831 eruption must have taken place elsewhere. A newly compiled dataset of...

At Campi Flegrei caldera, volcanic unrest hazards during 1982–1984 caused significant building damage and led to the evacuation of over 40,000 residents in the central town of Pozzuoli. Past hazard assessments in this region have focused on eruption hazards rather than on hazards from volcanic unrest. In this study, we developed a hypothetical unre...

The Piperno eutaxitic tuff, 20 m thick, interfingered with loose lithic-rich breccia, that outcrops at the base of Camaldoli hill (Campi Flegrei) (De Lorenzo, 1904) was interpreted by Rittmann (1950) to be a local air fall tuff. This welded tuff was reinterpreted by Rosi et al. (1996) as a pyroclastic flow and was considered as the proximal facies...

When an eruption from Mount Vesuvius buried the town of Pompeii in southern Italy in AD 79, it left behind not only intimate details of daily life in the Roman empire, but also an extraordinary record of how volcanoes behave. These archaeological and volcanic histories together offer a unique insight into how societies live and die in the shadow of...

Sulphur Springs Park (SSP) on Saint Lucia in the West Indies is an active hydrothermal area and major tourist attraction. Since 2015, networks of low-cost monitoring devices (active samplers and sensors) have been deployed to test their potential for monitoring the exposure to volcanic gases of SSP officials and visitors, and for establishing a cit...

Volcano-tectonic seismicity and ground movement are the most reliable precursors to eruptions after extended intervals of repose, as well as to flank eruptions from frequently active volcanoes. Their behavior is consistent with elastic-brittle failure of the crust before a new pathway is opened to allow magma ascent. A modified physical model shows...

The 1831 eruption of Babuyan Claro in the Philippines is regarded as one of the most significant volcanic climate forcing events of the nineteenth century. Modern databases have assigned the eruption a VEI of 4? and Magnitude of 4.7. Our analysis of historical sources, however, suggests that there was no such eruption in 1831 and that this date is...

Previous work has shown that the sensors for atmospheric CO concentration yielded comparable values to those obtained using conventional methods [1], whilst testing at Sulphur Springs connrms that the sensors can provide meaningful information at a fraction of the cost (c. one-tenth). As yet the initial designs for measuring CO ux have been unable...

Unrest at large calderas rarely ends in eruption, encouraging vulnerable communities to perceive emergency warnings of volcanic activity as false alarms. A classic example is the Campi Flegrei caldera in southern Italy, where three episodes of major uplift since 1950 have raised its central district by about 3 m without an eruption. Individual epis...

Volcanic crises are complex and especially challenging to manage. Volcanic unrest is characterised by uncertainty about whether an eruption will or will not take place, as well as its possible location, size and evolution. Planning is further complicated by the range of potential hazards and the variety of disciplines involved in forecasting and re...

Eruptions at large calderas are normally preceded by variable rates of unrest that continue for decades or more. A classic example is the 1994 eruption of Rabaul caldera, in Papua New Guinea, which began after 23 years of surface uplift and volcano-tectonic (VT) seismicity at rates that changed unevenly with time by an order of magnitude. Although...

Cultural and political contexts are important in determining the ways in which communities respond to volcanic eruptions. Understanding the manner in which communities and the State apparatus have coped with historic eruptions can provide insights into how responses have influenced vulnerability and resilience. The 1906 eruption of Vesuvius is well...

Understanding the potential evolution of a volcanic crisis is crucial for designing effective mitigation strategies. This is especially the case for volcanoes close to densely populated regions, where inappropriate decisions may trigger widespread loss of life, economic disruption, and public distress. An outstanding goal for improving the manageme...

Earth scientist observe many facets of the planet's crust and integrate their resulting data to better understand the processes at work. We report on a new data-intensive science gateway designed to bring rock physicists and volcanologists into a collaborative framework that enables them to accelerate their research and integrate well with other Ea...

The Campi Flegrei caldera in southern Italy is one of the greatest geohazard areas on Earth. Evidence of an active magmatic and geothermal system is provided by ongoing ground uplift, with volcano-tectonic and longperiod (LP) seismicity, the persistent degassing of ~1500 tonnes of CO2 per day, the presence of hot fumaroles at temperatures of 90–150...

Dacitic volcanoes such as Mount St Helens can erupt magma as lava domes that, in addition to simple effusion, frequently pass through episodes of major collapse and can also explode in vulcanian eruptions under suitable increases in gas pressure. Both dome collapse and vulcanian events can propagate pyroclastic flows and so extend the hazardous ran...

4), Jochem Kueck (4), Flavia Molisso (2), Joerge Erzinger (5), Christopher R.J. Kilburn (6), Agust Gudmundsson (7), Jean Pierre Burg (8), Alba Zappone (8), and David P. Hill (9) (1) INGV, Osservatorio Vesuviano, Napoli, Italy, (2) CNR-IAMC, Napoli, Italy, (3) CSIC, Barcelona, Spain, (4) ICDP, Potsdam, Germany, (5) GFZ, Potsdam, Germany, (6) UCL, Lo...

Accelerating rates of volcano-tectonic (VT) earthquakes are commonly observed during volcanic unrest. Understanding the repeatability of their behaviour is essential to evaluating their potential to forecast eruptions. Quantitative eruption forecasts have focused on changes in precursors over intervals of weeks or less. Previous studies at basaltic...

Quantitative analyses of seismic precursors to volcanic eruptions have focussed on volcanoes in compressional background stress fields at subduction zones. We here use the results from new laboratory rock-fracture experiments on alkali basalt from Mt Etna, in Sicily, to extend studies to volcanoes in extensional stress fields. Sequences of volcano-...

Dacitic volcanoes such as Mount St Helens are commonly associated with plinian eruptions. They can also erupt magma as lava domes that, in addition to simple effusion, frequently pass through episodes of major collapse and can also explode in vulcanian eruptions under suitable increases in gas pressure. Both dome collapse and vulcanian events can p...

Small-magnitude earthquakes and ground deformation are the precursors most frequently recorded before volcanic eruptions. Analogous signals (using acoustic emissions) have also been reported before the bulk brittle failure of crustal rock in the laboratory. Models based on laboratory and field data have focused on precursory behavior during deforma...

Magma degassing is an important control on whether an eruption will be explosive or effusive. Although the process of gas exsolution has been well-studied, the factors that determine how gases subsequently escape are still poorly understood, especially from high-viscosity magmas with evolved compositions, such as dacite. A preferred model for visco...

Reliable short-term forecasts of eruptions are crucial for responding effectively to a volcanic emergency. This is especially the case at volcanoes reawakening after centuries of repose, because such volcanoes are unlikely to have been under regular surveillance and, also, because those responding to the emergency are unlikely to have data from pre...

Volcanic eruptions are commonly preceded by spatial and temporal changes in patterns of deformation. Although a broad spectrum of behaviors have been reported, in many cases the changes include accelerating rates of strain and seismicity that culminate in an eruption. Various models have been proposed to explain such trends and potentially promise...

Dacitic volcanoes such as Mount St Helens are commonly associated with plinian eruptions. They can also erupt magma as lava domes that, in addition to simple effusion, frequently pass through episodes of major collapse and, under suitable increases in gas pressure, can also explode in vulcanian eruptions. Both dome collapse and vulcanian events can...

To investigate the physical controls on volcano-tectonic (VT) precursors to eruptions and intrusions at basaltic volcanoes, we have analyzed the spatial and temporal patterns of VT earthquakes associated with 34 eruptions and 23 dyke intrusions that occurred between 1960 and 1983 at Kilauea, in Hawaii. Eighteen of the 57 magmatic events were preced...

The Campi Flegrei volcanic district, in southern Italy, has been uplifted since 1968 by a net maximum of 3 m during the intervals 1968-1972 and 1982-1984. The uplift represents a permanent deformation against a background rate of subsidence of about 17 mm a-1. Previous models have reproduced the observed vertical deformation but not the full patter...

Mount Pinatubo, Philippines erupted on 7th June 1991, after 500years of repose and two months of detected seismic unrest. Accelerating volcano-tectonic (VT) earthquake rates in the final days before this eruption have previously been used to develop eruption forecasting models based on extension and coalescence of fractures in the volcanic edifice...

Increased exposure to volcanic hazard, particularly at vulnerable small islands, is driving an urgent and growing need for improved communication between monitoring scientists, emergency managers and the media, in advance of and during volcanic crises. Information gathering exercises undertaken on volcanic islands (Guadeloupe, St. Vincent and Monts...

Volcanic eruption forecasting models show that the strength and mechanical properties of volcanic rocks are a primary control on the behaviour of volcanic systems, especially during the approach to eruptions. The progressive failure of these rocks, recorded as sequences of small volcano tectonic earthquakes, can lead to the formation of new magma p...

Recurring patterns of behaviour occur among crustal precursors to eruptions after long repose, supporting the view that reliable forecasts of eruption are a realistic objective. In particular, volcano-tectonic events (or VT events, due to rock fracturing) tend to occur at an accelerating rate towards eruption. The behaviour is consistent with the a...

Conditions for fracturing are a primary control on the behaviour of volcanic systems, especially during the approach to eruption. We here present the results of deformation experiments under simulated volcanic conditions on a porhyritic andesite from ancestral Mount Shasta. Andesite was chosen as a representative material because it is common at su...

We use a fracture mechanics approach to model seismicity preceding volcanic eruptions. Starting with the fracture mechanics concept of a crack in an elastic body, we model crack growth around the volcanic conduit through the processes of crack interactions, leading either to the propagation and linkage of cracks, or crack avoidance and the inhibiti...

Recurring patterns of behaviour occur among crustal precursors to eruptions after long repose, supporting the view that reliable forecasts of eruption are a realistic objective. Robust constraints are that an eruption will occur when (1) the total seismic energy released by volcano-tectonic events (or VT events, due to rock fracturing) and bulk str...

A medium to short-term increase in the rate of volcano-tectonic earthquake events provides one of the most useful and promising tools for eruption forecasting, particularly at subduction-zone volcanoes reawakening after a long repose interval. Two basic patterns of accelerating seismicity observed prior to eruptions are exponential and faster than...

We present an integrated modelling and experimental approach to magma deformation and fracture, which we attempt to validate against field observations of seismicity. The importance of fracture processes in magma ascent dynamics and lava dome growth and collapse are apparent from the associated seismicity. Our laboratory experiments have shown that...

Emergency response plans have been formalised for only one third of the 32 volcanoes that have erupted in the past 500 years in Europe and its dependent territories. As local and tourist populations increase around the remaining 67%, so also the need for an appropriate emergency plan becomes more urgent. A cornerstone of such a plan is to ensure th...

A greater understanding of the physical processes occurring within a volcano is a key aspect in the success of eruption forecasting. By considering the role of fracture growth, interaction and coalescence in the formation of dykes and conduits as well as the source mechanism for observed seismicity we can create a more general, more applicable mode...

Following its plinian eruption on 18 May 1980, Mount St Helens (Washington State, USA) entered a period of intermittent lava-dome extrusion until 1986. Renewed extrusion was frequently preceded by accelerating rates of seismicity, with more precursory seismicity observed prior to eruptions later in the sequence. Here the failure forecasting method...

Increases in rates of seismicity and of ground deformation are common precursors to volcanic eruptions. Their behaviour is normally recorded as separate sets of variations with time. The two trends are rarely in proportion to each other, but show different precursory patterns. Ambiguity thus occurs as to which trend is the more reliable for forecas...

We present the results of an analysis of pre-eruptive seismicity at the basaltic volcanoes Kilauea and Mauna Loa, Hawaii, and Mt. Etna, Sicily. Seven out of the twenty-eight flank eruptions investigated are preceded by periods of elevated rates of VT seismicity exceeding 4 weeks in duration. Although the daily earthquake rate during these periods o...

Campi Flegrei caldera, west of Naples in southern Italy, has an exceptional documented record of ground deformation from Roman times onwards. Systematic recording began in the nineteenth century. For earlier dates, information has been obtained from archaeological studies and from contemporary descriptions of the locations of buildings, usually Rom...

Volcanic eruptions are commonly preceded by accelerations in the rate of occurrence of volcano-tectonic (VT) events. Consistent with the Voight Failure Forecasting Model, the accelerations tend to lie between exponential and hyperbolic (faster than exponential) limits. Such behaviour is remarkable, given that the detected VT event rate represents o...

Renewed extrusion at andesitic to dacitic lava domes and collapses of these domes are usually preceded by fracturing and frictional sliding of material in and around the lava dome and magma conduit. This is observed through the occurrence of shallow high frequency earthquakes. Samples of andesite from Mount Shasta in the Cascades, a typical materia...

The traditional classification of lava flows into pahoehoe and aa varieties reflects differences in how a flow can fracture its surface during advance. Both types of lava have a low strength upon eruption and require surface cooling to produce a crust that can fracture. Among pahoehoe lavas, applied stresses are small enough to allow the growth of...

Following its plinian eruption on 18 May 1980, Mount St Helens (Washington State, U.S.A.) entered a period of intermittent lava-dome extrusion until 1986. A re-analysis of the timing of volcano-tectonic (VT) earthquakes and eruptions indicates that: (1) all VT crises resulted in an eruption within 3 weeks (usually less than 10 days), (2) the majori...

[1] Accelerations in seismicity are important precursors to eruptions at volcanoes reawakening after extended repose intervals. These have previously been quantified for subduction-zone settings in terms of the linkage of crustal faults by shearing. Introducing a damage-mechanics criterion for the weakening of rock between major fractures, the mode...

Campi Flegrei, in Southern Italy, is an active caldera that has shown signs of unrest since 1969. Because the caldera has a population of 400,000 people, it is especially important to understand the mechanisms driving the unrest and their implication for the probability of a future eruption. Since its last ignimbrite eruption 12,000 years ago (whic...

The traditional classification of lava flows into pahoehoe, aa and blocky varieties reflects differences in how a flow can fracture its surface during advance. Pahoehoe and aa lavas have a low strength upon eruption and require surface cooling to produce a crust that can fracture. Among pahoehoe lavas, applied stresses are small enough to allow the...

The mechanical properties of volcanic rocks at high temperatures and low pressures are key properties in the understanding of a range of volcanological problems, in particular lava flow dynamics. The measurement of these properties on extrusive volcanic samples under the appropriate pressure and temperature conditions has a direct application in th...

The 1730—36 Timanfaya eruption on Lanzarote, in the Canary Islands, is the second largest historical effusion on record. During its final stages, in 1736, the eruption produced the Montaña de las Nueces flow-field, consisting of sheets of pahoehoe lava that, within 4 weeks, had covered 32 km2 and reached a maximum length of almost 21 km. The tholei...

Rapid, giant landslides, or sturzstroms, are among the most powerful natural hazards on Earth. They have minimum volumes of ~106–107 m3 and, normally preceded by prolonged intervals of accelerating creep, are produced by catastrophic and deep-seated slope collapse (loads ~1–10 MPa). Conventional analyses attribute rapid collapse to unusual mechanis...

When engineering methods are not cost-effective in reducing the danger from landslides, it is crucial that vulnerable communities are aware of the hazards they face and know how to respond in an emergency. Such awareness can best be maintained by a public-information programme designed around a population's existing perception of landslides. As a c...

Project RUNOUT has investigated methods for reducing the risk from large-volume landslides in Europe, especially those involving rapid rates of emplacement. Using field data from five test sites (Bad Goisern and Köfels in Austria, Tessina and Vajont in Italy, and the Barranco de Tirajana in Gran Canaria, Spain), the studies have developed (1) techn...

Among volcanoes reawakening after long repose intervals, the final approach to eruption (∼1–10 days) is usually characterised by accelerating rates of seismicity. The observed patterns are consistent with the slow extension of faults, which continue to grow until they connect a pre-existing array of subvertical fractures and so open a new pathway f...

Understanding how the strength of basaltic rock varies with the extrinsic conditions of stress state, pressure and temperature, and the intrinsic rock physical properties is fundamental to understanding the dynamics of volcanic systems. In particular it is essential to understand how rock strength at high temperatures is limited by fracture. We hav...

Giant, rapid landslides or sturzstroms are among the most powerful natural hazards on earth. They occur as whole mountainsides are displaced kilometers within minutes. Their speed, size, and travel distance are often taken to imply that sturzstroms have an unusually high mobility compared to smaller landslides, and this has driven numerous investig...

The primary goals for Project RUNOUT were to develop and test physical models for the catastrophic collapse and runout of giant landslides, and to use these to improve strategies for mitigating the hazard from such mass movements. These goals have been achieved, together with the creation of databases for the improved monitoring of unstable slopes...

3He/4He ratios in lavas erupted during the last 360 years at Mt. Vesuvius are between 2.2 and 2.7 RA (RA = atmospheric ratio of 1.39 × 10−6), and are among the lowest values measured in young volcanic rocks. They are also identical to values measured in summit crater fumaroles sampled during 1987–1991. This agreement indicates that the 3He/4He rati...

Breakout of magmatic activity at Soufriere Hills volcano, Montserrat, was preceded by a tenfold increase in rate of earthquake occurrence. A new model of subcritical rock failure shows that this increase is consistent with the growth, possibly episodic, of the magma conduit at a rate controlled by progressive weakening of the host country rock. The...

Sturzstroms are giant landslides that travel kilometers within minutes. Data from terrestrial examples of 0.001-10 km3 suggest that their runout lengths increase in proportion to the square root of their volume. This trend is investigated assuming that runout is controlled by fragmental flow. The results indicate that runout lengths depend on the p...

The results of a preliminary U-series study of the timescale of magmatic processes at Vesuvius are presented. Phonotephrites of the 1944 eruption of Vesuvius show 0–15% – and 350–1150% – disequilibria. Apparent U–Th internal isochrons for a lava and a cumulate nodule suggest crystal residence times of 12 and 39 ka, respectively. A tephra sample sho...

&#112As the regions around active volcanoes succumb to large increases in population, particularly in the developing world where most of the high-risk volcanoes are located, the threat posed by eruptions becomes increasingly serious. Improvements in eruption forecasting are critical to combat this situation, for reducing injury and loss of life, an...

Studies of lava flows on Mars must still rely largely on imaging data obtained by the Viking mission. Therefore, flow morphology remains the prime data from which effusion and magma characteristics must be inferred. This study uses three complementary lava flow models to infer emplacement characteristics of several of martian flows. We have previou...

Subaerial lava flows and flow fields show a restricted range of evolutionary sequences. The sequences are related to the traditional classification of pahoehoe, aa and blocky lava, and each is distinguished by a characteristic association of morphological and dynamical features. These features, which include crustal growth and morphology, the forma...

Detailed sampling of the Vesuvius lavas erupted in the period A.D. 1631–1944 provides a suite of samples for comprehensive chemical analyses and related studies. Major elements (Si, Ti, Al, Fetotal, Mn, Mg, Ca, Na, K and P), volatile species (Cl, F, S, H2O+, H2O− and CO2), and ferrous iron (Fe2+) were determined for one hundred and forty-nine lavas...

Lava flows can be considered as hot viscous cores within thinner, solidified crusts. Interaction between crust and core determines a flow's morphological and dynamical evolution. When the lava core dominates, flow advance approaches a steady state. When crusts are the limiting factor, advance is more irregular. These two conditions can be distingui...

Several remote sensing techniques have been developed to determine various properties of lava flows. We are currently focusing on three such techniques to interpret Martian lava flows on Alba Patera, which are based on measurements of distal flow lobe widths which can be used to infer silica content; convolution of flow margins which can distinguis...

Lava flowfields consist of one or more flows. Four ideal emplacement regimes are recognized: that for single flows and that for flowfields dominated by (1) widening, (2) thickening, or (3) lengthening, as a result of generating new flows. Most aa and blocky lavas belong to the flowfield widening or single-flow regimes. These two regimes are analyze...

The relationships obtained by Kilburn and Lopes (1988, 1990) for their models of lava flow fields were used to calculate the duration of the emplacement, the average discharge rates, and the average velocities of lavas for the Martian volcano Alba Patera, on which two distinct planimetric types of lava flow field were identified. The validity of us...

Most of Etna’s historical lavas have produced aa flow-fields. Despite the classification, they support a variety of surfaces in both the pahoehoe and aa categories. From observations of surface features at metre to submillimetre scales, two morphological series have been recognized: a sequence from pahoehoe to aa along a single flow, and an evoluti...

The historical lavas on Mount Etna provide a large body of data for examining the growth of aa flow fields. A flow field, the final product of an eruption, is composed of one or more flows. Flow generation depends on the ratio SR/SD of crustal retaining strength (SR) to stress driving the lava outward (SD), rate of flow thickening h, and the time f...

The morphology of a lava flow is strongly influenced by its rheological structure. The rheological structure is, in turn, dependent on numerous factors including: (1) bulk composition, (2) crystallingity, (3) vesicularity, and (4) crustal development. Identifying which of the latter factors are most significant, and hence most readily investigated...