We established the phase equilibria of a representative tephriphonolitic sample of the 1631 eruption of Vesuvius (Italy). Experiments were conducted at 100 MPa, in the temperature range 950–1050 °C for melt water content ranging from 1.3 to 3.2 wt%, and at an oxygen fugacity (fO2) of NNO+1 to NNO+3 (one to three log unit above the fO2 of the Ni-NiO solid redox buffer). Results show that clinopyroxene

The 1783–1784 Laki eruption was one of the most severe natural catastrophes to occur in Iceland since settlement (around 870 CE). Vegetation damage by sulphate aerosol and fluorine poisoning caused a massive decimation of livestock which brought famine and excess deaths of 1.6 of the population. 18th Century Iceland was a Danish dependency and, despite the abundance of fish in the surrounding waters

Popocatepetl volcano located in central Mexico has been erupting since December 1994 and since then many studies have been carried out in order to understand its eruptive behavior and assess the volcanic hazard since more than 25 million people are at risk. Nevertheless, few geophysical studies have been conducted in order to image the structure of the volcano. For this reason, we carried out magnetotelluric

The genesis, distribution and hazards associated with monogenetic volcanic fields pose particular difficulties derived from their dispersed character. Establishing a relationship between the spatial and the age distributions of volcanic cones is necessary both to understand the nature of monogenetic field formation and evolution and to set supported hazard-assessment criteria. We present here a new

Hydrothermal systems with active surface expressions are important natural source of atmospheric mercury. Here we report on the first simultaneous assessment of gaseous elemental mercury (GEM) and major volatiles (H2S and CO2) fluxes from the fumarolic system of Pisciarelli, currently the most active at the Campi Flegrei caldera (CFc), Naples (Italy). This was achieved via a GPS-synchronized Lumex

Avachinsky, Kozelsky, and Koryaksky volcanoes form one of the most volcanically active clusters in the Kamchatka volcanic arc and are located in close proximity of the cities of Petropavlovsk-Kamchatsky and Elizovo – the most populated area in Kamchatka. In this paper, we report a compilation of new and revised previously published data on the eruptive history of these volcanoes during the past 13

Since 1994 Popocatépetl volcano has extruded 85 lava domes, each of which has been destroyed by Vulcanian-style explosions. The paroxysmal Vulcanian explosion of 22 January 2001 has been unique by generating multiple pyroclastic density currents (PDCs). Scientists and Civil Protection authorities have used those PDCs to remap the high-risk hazard zone of the volcano, although little study has been

Anisotropy of magnetic susceptibility (AMS) and anhysteretic remanent magnetization (AARM) are tools to characterize flow structures and emplacement conditions of volcanic and subvolcanic bodies, directly related to magnetic fabrics. An AMS and AARM study was performed to contribute to the understanding of the processes involved in magma transportation and emplacement dynamics of the volcanic and subvolcanic

Cubilche Volcanic Complex (Imbabura Province, Ecuador) includes three morphologically well-preserved eruptive centers: in increasing size, Cunrru Dome Complex (3300 m above sea level, m asl), Panga Ladera (3420 m asl) and Cubilche (3836 m asl). As this complex is poorly known, we conducted a volcanological study of its evolution by combining geomorphological, lithostratigraphic, radiocarbon (14C),

We have reassessed the mode of advance of lava erupted in the 1990s from Unzen Fugen-dake Volcano in northwestern Kyushu, Japan. The apparent viscosity of Unzen lava had been estimated to be 0.9–4.2 × 1010 Pa s from the observed lava surface velocity in 1991, using Jeffreys model, based on the assumption that the lava was a Newtonian or Bingham fluid. In contrast, the viscosity of synthetic groundmass

We performed repeated three-dimensional seismic tomography in 2009–2018 for the area influenced by the intersection of the Silvia–Pijao (Buesaco) and Cauca–Almaguer fault systems beneath Galeras volcano, Colombia. We analyzed two periods, 2009–2012 and 2013–2018, which were characterized by explosive eruptive activity and relative quiescence at Galeras, respectively. We used P- and S-wave arrival times

Active lava surfaces emplaced during effusive eruptions are typically observed in the form of lava flows, lakes, or domes. There are numerous volcanoes on Earth that regularly produce active lava including Kīlauea volcano in Hawai'i, which had a continually-active lava flow field from the 1980s until the end of the last eruptive phase in 2018. During the last decade of that period, it also had a persistent

The Brown Tuffs (BT) are widespread reddish-brown to grey, ash-rich pyroclastic deposits recognized in the stratigraphic sequences of the Aeolian Islands and Capo Millazzo peninsula (Sicily) that span the last 80 ky. They have very homogeneous lithological, textural and sedimentological features which make it difficult to reliably correlate units on the islands to proximal units in the source areas

In ancient volcano-sedimentary successions, the reconstruction of the facies architecture may be difficult because of incomplete exposure, deformation, metamorphism and hydrothermal alteration. The distinction of lavas or domes from shallow intrusions is critical for the ordering of volcanic, intrusive, sedimentary and hydrothermal events. Both lavas and shallow intrusions typically have porphyritic

Rabaul in Papua-New-Guinea is an extremely active andesitic caldera complex that displays a large spectrum of eruption styles. Since 1878, four sub-plinian (VEI-4) and ten VEI 1–3 (effusive, strombolian, vulcanian) eruptions occurred from Tavurvur and Vulcan, the two main active vents. We study pumiceous tephra, ballistic bombs and a lava flow from five of these eruptions to investigate (1) magma ascent

A major seismovolcanic crisis has afflicted the islands of Mayotte, Comoros Archipelago, since May 2018, although the origin is debated. Magnetotellurics (MT), which is sensitive to hydrothermal and/or magmatic fluids and can map the subsurface electrical resistivity structure, can provide insight by revealing the internal structure of the volcanic system. In this paper, we report the results of a

Shallow, implosive non-double-couple (NDC) earthquakes have been detected beneath Unzen Volcano, Japan, by a routinely operated seismometer network. Here, we analyze the waveforms from 14 temporary seismic stations around Mt. Fugen (Fugendake) and Heisei-Shinzan Lava Dome, which formed during the 1990–1995 eruptions, to further investigate this shallow seismicity. We also estimate the subsurface electrical

Subsurface ice cryofluids and ice interactions with ammonia for cryovolcanic materials give the potential ingredients for the formation of mud volcanoes on Pluto. In order to constrain the possible morphology from images acquired by the New Horizons spacecraft, we have modeled the formation of mud volcanoes, isostatic layers of ice overlain by denser material, from a series of possible solid-liquid

The estimation of the volume of volcanic flows during an ongoing eruption is challenging but this information is crucial for improving risk assessment and for forecasting future events. Although previous studies have shown the ability of TanDEM-X satellite data to derive the thickness and the volume of lava flow fields during effusive eruptions, the method has not been explored yet for pyroclastic

Despite their generally low volume fraction, FeTi oxides have the potential to greatly influence the eruptive style because they lower the supersaturation pressure for heterogeneous bubble nucleation. Once nucleated, bubbles respond fast to pressure changes, fostering rapid expansion and explosive behavior. Yet, oxide microlite quantifications are often absent from data of explosive products. We used

Near-seafloor bathymetric and magnetic data have been collected by Autonomous Underwater Vehicle (AUV) and manned submersible (DSS) over a volcanically active area southeast of Futuna Island, French Territory of Wallis-and-Futuna, in the Southwestern Pacific Ocean. Located at the edge of the Lau and North Fiji basins, at the convergence of the Pacific and Australian plates, this area is characterized

Surface temperature at a volcanic system is the result of a mixture of two heat sources originating one from above and another from below the ground surface. The atmosphere significantly affects the surface's temperature of the volcano, and removal of the atmospheric effect is required for meaningful interpretations prior to any characterization of anomalous volcanic activity. Time series of meteorological

Successful management of geothermal energy requires detailed understanding of physical and chemical conditions within the field prior to exploitation. It is thus crucial to identify fluids involved and their residence times, as well as the heat source, so as to assess the potential of the resource in terms of energy production. To this end, a geochemical study of relatively undisturbed fluids from

To comprehend the hydrothermal potential beneath the Mt. Hasan composite volcano and its vicinity, three-dimensional analyses of magnetotelluric data collected at 27 sounding locations were utilized to develop electrical conductivity (or its reciprocal resistivity) images in southwest Cappadocia, Central Anatolia, Turkey. A low resistivity anomaly associated with a clay cap was observed in the resulting

Using continuous data from ground-based Global Satellite Navigation System (GNSS) receivers in Java and Sumatra, Indonesia, we studied the response of ionospheric total ionospheric electron content (TEC) to the 2010 Nov.5 eruption of the Merapi volcano in central Java. We then compared the results with the case of the 2014 Feb.13 eruption of the Kelud volcano, eastern Java. The TEC showed a quasi-periodic

Recent advances in the development of in-situ chemical and temperature sensors have shown great promise as a means to investigate time series changes in marine and terrestrial hydrothermal systems. Here we apply this technology to assess chemical and physical controls on sublacustrine vent fluids in Yellowstone Lake, WY. Autonomous sensor systems were deployed in August 2017 using ROV assets to position

Volcanoes frequently generate infrasound signals that need to be processed before they can be used to monitor and track changes in eruptive activity. Unsupervised machine learning is complementary to existing processing methods and can be used for data exploration to identify features of interest in the data. Here, I examine three days of infrasound data from Mount Etna, Italy, that encompasses the

Following on the discovery (in 2011) of a layer of distal tephra from the Pomici di Avellino eruption (Somma-Vesuvius, EU5) in the Agro Pontino (southern Lazio, Italy), further detailed study of the Holocene sediment archives in this graben and in the nearby Fondi coastal basin showed that distal tephra from this EU5 eruption occurs as a rather continuous, conspicuous layer. Two other, less conspicuous

Paroxysmal activity represents an end-member in the common range of activity at mafic arc volcanoes, characterised by rapid transitions across the effusive-explosive interface and thus posing significant challenges to hazard assessment. Conceptual models to explain changes in the frequency and magnitude of these paroxysmal events are based either on magma recharge or an increase in gas flux, largely

The Paymogo Volcano-Sedimentary Alignment (PVSA) is an essentially igneous sequence associated with VHMS deposits of the Iberian Pyrite Belt. Unlike other areas of this Iberian mining district, where mafic igneous rocks are abundant, in the PVSA these are essentially felsic. Two facies associations have been distinguished based on petrographic and chemical features: a lower dacite facies association

Real-time monitoring of volcanic tephra fallout rate is an important factor to predict ash plume dispersion and to mitigate risk to air traffic. Ground-based weather radar has been one of the fundamental instruments to detect the plume and derive eruptive source parameters, such as the tephra fallout rate. The current work presents the use of two small and compact X-band Multi-Parameter (X-MP) radars

We conducted a petrological study of the layered gabbros and peridotites outcropping in the cirque of Salazie, combining field investigations, geochemistry, petrography and, mineralogy to constrain the magmatic evolution of Piton des Neiges volcano (La Réunion). Three new hectometer-long outcrops are reported here (Sites 1, 2 and 3) in addition to the gabbroic series (hereafter named Site 4) previously

Crustal extension of the southern portion of the Taupo Rift in the Central North Island of New Zealand is mostly accommodated by normal faulting and rare dike intrusions. To better understand how extension is accommodated and how volcanoes and faults interact, we provide a new integration of the tectonic and volcanic history of this young section of the Taupo Rift from geological evidence. Fault acceleration

Strain localisation structures, such as shear fractures and compaction bands, are of importance due to their influence on permeability and therefore outgassing, a factor thought to influence eruptive style. In this study, we aim to develop a better understanding of strain localisation in porous volcanic rocks using X-ray tomographic images of samples of porous andesite (porosity = 0.26) acquired before

Previous studies have found discrepancies concerning the seismic radiation between planar and curved faults; moment tensor (MT) interpretations, seismic moment estimation and waveforms change dramatically when the rupture is not planar. Therefore, assuming a point source on a planar fault for earthquakes in volcanic environments can be an oversimplification that needs to be addressed if we observe

This paper deals mainly with acidic sulphate-chloride (ASC) waters that are discharged at volcanic edifices, generally, not associated with crater lakes. Geographically, the largest number of such manifestations were found on Japanese and Kuril Islands. These waters are formed by: (1) condensation of magmatic vapor under shallow conditions and/or (2) dissolution of magmatic gases in underground waters;

Geophysical methods of analysis were applied, in order to investigate the deep structure and the geothermal potential of the Methana Volcano (NE Peloponnesus, Greece). The study is based on a re-evaluation and reinterpretation of legacy magnetotelluric (MT) data with modern analysis methods, as well as 3-D inversion of aeromagnetic data constrained by in situ measurements of magnetic susceptibility

The Palinuro volcanic chain (PVC) is located about 80 km offshore the Campania region (Italy) in the southern sector of the Tyrrhenian Sea. The chain consists of 15 volcanic edifices aligned in an E-W direction with two distinct major seamounts (Palinuro and Glabro). They cover a 90 km long and 20 km wide area, with a present-day volume of 2700 km3. Palinuro volcanism emplaced between 0.8 and 0.3 Ma

The upper portion of the Huichapan Ignimbrite (UHI), central Mexico, is a non-welded massive ignimbrite characterized by large and well-developed fines-poor elutriation pipes. We conclude that the most important pipe-forming process in the Huichapan Ignimbrite was deposition-triggered aggregative-type segregation, and this process is enhanced by positive pore-pressure feedback during the rapid settling

Magma is transported through the lithosphere as dykes which, during periods of unrest, may feed eruptions at the surface. The propagation path of dykes is influenced by the crustal stress field and can be disturbed by crustal heterogeneities such as contrasting rock units or faults. Moreover, as dykes propagate, they themselves influence the surrounding stress field through processes of stress transfer

Since the 1970s, temporal variations of hydrothermal discharge and thermal output from the numerous hydrothermal features in the Yellowstone Plateau Volcanic Field (YPVF) have been studied by measuring the chloride flux in the major rivers. In this study, the sources, fate, and flux of solutes in the Fall River and its major tributaries, in southwest Yellowstone National Park, were determined. The

This paper explores the use of six different clustering-based methods to classify long-period and volcano-tectonic seismic events and to find possible overlapping signals of non-volcanic origin that could occur at the same time or immediately after the occurrence of volcano-seismic events. According to the explored classifiers space, the BIRCH method with k = 2 was chosen as the best model in the classification

Hydrothermal regions are affected by a wide variety of phenomena, including ground inflation and deflation episodes. Among them, calderas offer the opportunity to study the complex interactions between magmatic processes at depth and permeable rocks saturated with fluids in the upper sedimentary layers. One of such regions is the Campi Flegrei caldera in southern Italy, where several source models

Gravitational instability of discrete lava lobes in an active dome-building volcano may generate rockfalls that travel up to hundreds of meters from the summit. Understanding the behaviour of rockfalls is important for volcanic hazard assessment as rockfalls can precede large dome collapses that generate pyroclastic flows. Here, we investigate the mechanisms, trajectory, velocity and seismic characteristic

Shape analysis is of paramount importance in sedimentology. Particle morphology is a very useful texture parameter that provides information about particle history and is used to characterize and classify sedimentary material. Particle shape description has been both an important and a controversial subject. The most convincing description of shape defines particle shape by three hierarchical parameters:

For some volcanoes, the only evidence for past eruption is provided by historical accounts. When interpreted carefully, these have the potential to be a rich source of information, and yet they have so far been under-utilised in reconstructing eruption histories. The navigator Thomas Forrest describes a large eruption at Makaturing volcano, southern Philippines, in approximately 1765 that he considers

The volcanic sequences in eastern Iceland provide a cross-section of magmatic activity from the Iceland rift system throughout the Miocene. This study focuses on a high precision age determination campaign of a single Miocene volcanic system, the Breiðdalur central volcano and associated dyke swarm, in order to quantify its evolution. The central volcano consists of: a lower flank of mafic lavas erupted

Volcano-seismic signatures are the convolution of source and path effects. The source signature provides important information about the dynamic rock deformation and fluid resonance processes within the volcano, but path effects are the result of the volcanic plumbing, the edifice physical conditions, and the complex geological structure. Complicating the inversion of seismic data further, is the influence

Seismic imaging is used in this work, to reconstruct the shallow structure of the Solfatara crater, a surface marker of deep magmatic activity inside Campi Flegrei caldera (Southern Italy). We analyze the 1D orthogonal seismic arrays deployed in NNE-SSW directions for 400 m through the Solfatara crater during the recent active experiment RICEN (Repeated Induced Earthquake and Noise) performed in the

The Cenozoic harrats (lavafields) of western Arabia constitute one of the major volcanic areas of the world. Recent precise chronometric dating of volcanic rocks in Harrat Rahat makes it possible to outline a detailed chronology of volcanic activity. Likewise, recent advances in archaeology have demonstrated that early humans repeatedly occupied the Arabian Peninsula in the Pleistocene. Most archaeological

Deception Island is one of the most active volcanoes in Antarctica, with more than 20 monogenetic eruptions during the Holocene. The latest episodes of 1967, 1969, and 1970 have shown that volcanic activity on Deception Island can become a concern for tourists, scientists, and military personnel working on or near the island. The objective of this work is to identify eruptive processes and the geomorphic

Marine tephrochronology provides a good alternative to study the eruptive history of volcanic islands and overcome the problem of poorly preserved on-land outcropping. Here, we provide new observations on the recent volcanological evolution (<40 kyrs) of Montagne Pelée (Martinique, Lesser Antilles) based on the tephrochonological study of a marine core from Site U1401, sampled during IODP Expedition

Volcanic eruptions are driven by the growth of gas bubbles in magma. The timing and rate of bubble growth are important because they determine whether enough gas pressure can develop to fragment the melt. Bubbles grow in response to decompression and diffusive transport of dissolved volatiles (predominantly H2O) that exsolve into the bubbles. Growth is resisted by the viscosity of the melt. Both melt

Present efforts in volcano monitoring, particularly in Southeast Asia, rely on the combination of local data (generally gathered at less than 100 km from the volcano), and satellite remote sensing. While this combination has its strengths, there are still weaknesses that the use of ground-based remote sensing data - such as distant infrasound measurements - could help alleviate. Infrasound offers tools

This article collects and presents nineteenth-century ethnographic evidence from the Newer Volcanics Province of Australia and explores how volcanism was recorded and understood in Aboriginal oral traditions. It investigates whether Aboriginal Australian oral traditions can be understood as persistent eyewitness accounts of volcanic eruptions in the Newer Volcanics Province, how and what kind of geological

Accurate quantification of the emission rate of sulphur dioxide (SO2) from volcanoes provides both insights into magmatic processes and a powerful monitoring tool for hazard mitigation. The primary method for measuring magmatic SO2 is Differential Optical Absorption Spectroscopy (DOAS) of UV scattered sunlight spectra, in which a reference spectrum taken outside the plume is used to quantify the SO2

Detailed mapping and geochronological investigations of edifice-forming materials reconstruct the growth history of Tongariro volcano, New Zealand, and subdivide the edifice into thirty six distinct units which are organised into twelve formations and constituent members. Twenty nine new 40Ar/39Ar age determinations, along with published K/Ar ages combined with volume estimates, petrographic observations