We find that volcanic hazards vary across the historically active Los Tuxtlas volcanic field (LTVF), with large scoria cones, and likely larger magnitude and intensity eruptions, concentrated in a NW–SE trending band and maars distributed at lower elevations. As eruptive processes vary in systematic ways across the LTVF that reflect the structure and topography of this volcanic field, spatial variations

Slab window basalt cycles in extra-Andean Patagonia formed in a main-plateau and a post-plateau stage, during glacial and interglacial events. Here, we provide field, geochemical and geochronological data of Pliocene basalts and volcanoes from the north of Viedma lake (49° 20′–49° 30′ S). These basalts share the alkaline composition and enrichment in incompatible elements of post-plateau lavas, in

Volcanologists frequently use grain size distributions (GSDs) in tephra layers to infer eruption parameters. However, for long-past eruptions, the accuracy of the reconstruction depends upon the correspondence between the initial tephra deposit and preserved tephra layer on which inferences are based. We ask: how closely does the GSD of a decades-old tephra layer resemble the deposit from which it

The seismic signals of pyroclastic flows and rockfalls of incandescent fragments of lava dome and flows (PFIRs), generated during the seven lava dome–building episodes of the 1998–2017 eruption at Volcán de Colima, México, are collated. Our article presents an overview of a series of published relationships between lava dome dynamics and PFIR seismic signatures. The eruption episodes were characterized

Kīlauea Volcano’s 2018 lower East Rift Zone (LERZ) eruption produced exceptionally high lava effusion rates and record-setting SO2 emissions. The eruption involved a diverse range of magmas, including primitive basalts sourced from Kīlauea’s summit reservoirs. We analyzed LERZ matrix glasses, melt inclusions, and host minerals to identify melt volatile contents and magma storage depths. The LERZ glasses

The load a tephra fall deposit applies to an underlying surface is a key factor controlling its potential to damage a wide range of assets including buildings, trees, crops and powerlines. Though it has long been recognised that loading can increase when deposits absorb rainfall, few efforts have been made to quantify likely load increases. This study builds on previous theoretical work, using an experimental

Modeling lava flow propagation is important to determine potential hazards to local populations. Thermo-rheological models such as PyFLOWGO track downflow cooling and rheological responses for open-channel, cooling-limited flows. The dominant radiative cooling component is governed partly by the lava emissivity, which is a material property that governs the radiative efficiency. Emissivity is commonly

Whakaari is New Zealand’s most active volcano, and its last major magmatic eruption occurred during a protracted episode between 1976 and 2000. This eruption episode involved a sustained phase of heightened unrest, punctuated by regular, and small-volume, phreatic, magmatic and phreatomagmatic eruptions. We examine the scoria sample suite erupted throughout this period to develop a model for the storage

During continental rifting, strain and magmatism are believed to localize to narrow magmatic segments, while the rift margin is progressively abandoned. We integrate volcanological, geochemical, petrological and seismic data from the Ma’Alalta volcanic field (MVF) near the western margin of Afar, to show that the MVF is an active magmatic segment. Magmatism in MVF initiated with lava flows and large-volume

The Laguna del Maule volcanic field in Chile has been exhibiting unrest since 2005. New GPS and InSAR data reveal a second episode of accelerated deformation beginning in late 2016 and continuing through May 2020, with an uplift rate > 290 mm/year between 2019 and 2020. To explain the spatial and temporal pattern of deformation, we apply a dynamic model of viscous magma flowing through a conduit into

Heard Island is a subantarctic volcanic island in the southern Indian Ocean and includes Australia’s only active volcano, Big Ben (2813 m high, 18 km diameter). The most recent eruption of lava at Big Ben occurred in November 2020. Heard Island is the southernmost subaerial exposure of the Kerguelen Plateau, a mainly submerged large igneous province formed as a result of the activity of the Kerguelen

In December 2018, an unusually large intra- and extra-caldera eruption took place at Ambrym volcano (Vanuatu). The eruption drained the volcano’s five active lava lakes and terminated, at least momentarily, the surface activity that had been ongoing for decades to hundreds of years, sustaining the largest recorded persistent degassing on the planet. Here, we investigate the mechanisms and dynamics

Future occurrence of explosive eruptive activity at Cotopaxi and Guagua Pichincha volcanoes, Ecuador, is assessed probabilistically, utilizing expert elicitation. Eight eruption types were considered for each volcano. Type event probabilities were evaluated for the next eruption at each volcano and for at least one of each type within the next 100 years. For each type, we elicited relevant eruption

The nature of sub-volcanic alteration is usually only observable after erosion and exhumation at old inactive volcanoes, via geochemical changes in hydrothermal fluids sampled at the surface, via relatively low-resolution geophysical methods or can be inferred from erupted products. These methods are spatially or temporally removed from the real subsurface and thus provide only indirect information

The microstructure and mineralogy of volcanic rocks is varied and complex, and their mechanical behaviour is similarly varied and complex. This review summarises recent developments in our understanding of the mechanical behaviour and failure modes of volcanic rocks. Compiled data show that, although porosity exerts a first-order influence on the uniaxial compressive strength of volcanic rocks, parameters

A Correction to this paper has been published: https://doi.org/10.1007/s00445-021-01456-1

The occurrence of groundmass crystals reveals the shallow conduit process of magmas, which affects the behavior of eruptions. Here, we analyzed groundmass microtextures of ash samples from the 2018 eruption of Shinmoedake volcano, Japan, to evaluate the change of magma ascent conditions during the eruption sequence. The eruptive activity changed from ash venting (Phase 1: March 1–6) to lava effusion

Exposure to volcanic ash is a long-standing health concern for people living near active volcanoes and in distal urban areas. During transport and deposition, ash is subjected to various physicochemical processes that may change its surface composition and, consequently, bioreactivity. One such process is the interaction with anthropogenic pollutants; however, the potential for adsorbed, deleterious

Few monogenetic eruptions that produced lava flows have occurred in historical times, limiting the observations of their impact on human settlements. However, rheological models based on morphological and petrological datasets can contribute to decipher the eruptive dynamics and durations of ancient eruptions. The Malpaís de Zacapu, a temporal-spatial monogenetic volcano cluster at the western margin

Dense, glassy pyroclasts found in products of explosive eruptions are commonly employed to investigate volcanic conduit processes through measurement of their volatile inventories. This approach rests upon the tacit assumption that the obsidian clasts are juvenile, that is, genetically related to the erupting magma. Pyroclastic deposits within the Yellowstone-Snake River Plain province almost without

Although erosion during high-energy passage of a pyroclastic density current (PDC) causes great damage, analyses of the effects of such erosion are sparse in scientific literature compared to observations and interpretations of depositional processes. In this paper, we review observations of surfaces where PDCs have eroded sets of grooves that provide information on the erosion process. We postulate

The 2018 eruption on the lower East Rift Zone of Kīlauea Volcano produced one of the largest and most destructive lava flows in Hawai’i during the past 200 years. Over the course of more than 3 months, twenty-four fissures erupted, and the rate of lava effusion varied by two orders of magnitude, with significant implications for evolving flow behavior and hazards. Syn-eruptive data were collected to

This work presents the results of a hydrogeochemical study conducted in two galleries on the island of Tenerife: Fuente del Valle and San Fernando, during a 2-year period with weekly sampling (July 2016 to July 2018). Groundwater temperature, pH, and electrical conductivity exhibited stable values throughout the study period, while significant temporal variations were observed in the total alkalinity

Hawaiian and other ocean island lava flows that reach the coastline can deposit significant volumes of lava in submarine deltas. The catastrophic collapse of these deltas represents one of the most significant, but least predictable, volcanic hazards at ocean islands. The volume of lava deposited below sea level in delta-forming eruptions and the mechanisms of delta construction and destruction are

A Correction to this paper has been published: https://doi.org/10.1007/s00445-021-01436-5

The original version of this article unfortunately contained a mistake.

Understanding interactions between tectonic faults and a nearby active volcano is often realized by combining seismic and field observations. A good example of such an interaction is the Caviahue caldera. It is located in an intra-arc extensional pull-apart basin, within a transition zone joining the northern part of the right-lateral strike-slip Liquiñe-Ofqui Fault System and the thrust-fault Antiñir-Copahue

Cerro Overo maar and La Albóndiga lava dome are two independent monogenetic volcanoes located in the Central Volcanic Zone of the Andes in northern Chile, close to the active Lascar and Chiliques volcanoes. Cerro Overo maar was formed <77 ka ago by explosive-effusive eruptions, including phreatomagmatic activity, while La Albóndiga lava dome (Pleistocene) is the result of magmatic explosive-effusive

We have coupled three independent methods to investigate the time evolution of eruptive intensity during the sub-Plinian and Plinian phases of the 3600-year BP Late Bronze-Age eruption of Santorini Volcano: (1) mass eruption rate based on new lithic isopleth maps for multiple layers of the fall deposit, (2) magma decompression rate calculated from vesicle number densities, and (3) magma decompression

Despite the common occurrence of heterogeneous andesitic eruptions, few studies have investigated the compositional effects on microlite crystallization and vesiculation in co-erupted natural samples. In 2006, Augustine Volcano erupted compositionally heterogeneous andesites that range from 56.4 to 63.3 wt% SiO2 and include two endmember lithologic groups: low-silica andesite (LSA) and high-silica

Particularly in the presence of a hydrothermal system, many volcanoes output large quantities of heat through the transport of water from deep within the edifice to the surface. Thus, heat flux is a prime tool for evaluating volcanic activity and unrest. We review the volcanic unrest at La Soufrière de Guadeloupe (French West Indies) using an airborne thermal camera survey and in situ measurements

A Correction to this paper has been published: https://doi.org/10.1007/s00445-021-01441-8

Textures and whole-rock chemistry, as well as mineral composition, were analyzed in megaspherulites (high-temperature crystallization domains [HTCDs]) that formed in different geographical and geotectonic contexts and during different geological periods (Silver Cliff, CO, USA—Paleogene; El Quevar, Argentina—Miocene; Meissen Volcanic Complex, Germany—Late Carboniferous). All of these megaspherulites

Green core clinopyroxenes are reported from the basanites of the Petpenoun volcanoes of the Noun Plain, in the Cameroon volcanic line (CVL). These clinopyroxenes have augite and/or diopside rims and mantles, and green cores with variable chemical composition. Compositionally, three kinds of green cores are distinguished: (i) wollastonite-hedenbergite cores (green core I); (ii) diopside cores (green

We examined the evolution of the magma feeding system at Zao volcano (NE Japan) during seven episodes of Komakusadaira pyroclastic activity (ca. 33–12.9 ka). The rocks, which are calc-alkaline and medium-K basaltic andesite to andesite (54.9–59.5% SiO2), are herein suggested to have been derived from two main magmatic end-members: silicic andesite magma (59~60% SiO2, 940~970°C, cpx-opx-plg as phenocrysts)

Understanding the processes that drive explosive-effusive transitions during large silicic eruptions is crucial to hazard mitigation. Conduit models usually treat magma ascent and degassing as a gradual, unidirectional progression from bubble nucleation through magmatic fragmentation. However, there is growing evidence for the importance of bi-directional clastogenic processes that sinter fragmented

Understanding the location, intensity, and likely duration of volcanic hazards is key to reducing risk from volcanic eruptions. Here, we use a novel near-real-time dataset comprising Volcanic Ash Advisories (VAAs) issued over 10 years to investigate global rates and durations of explosive volcanic activity. The VAAs were collected from the nine Volcanic Ash Advisory Centres (VAACs) worldwide. Information

Nyiragongo and Nyamuragira are two active volcanoes of the Western branch of the East African Rift in the Virunga area. They were built at the Kivu rift axis ca. 12,000 years ago and set above two tectonic steps separated by the Kameronze Fault. Both volcanoes have displayed a succession of intra-crater and flank eruptions that have been observed and documented since the end of the nineteenth century

Lava dome collapses are a major threat to the population living near such volcanoes. However, it is not possible to forecast collapses reliably because the mechanisms are not clearly understood, due partly to the lack of continuous observations of such events. To address this need for field data, we have developed new monitoring stations, which are adapted to the volcanic environment. The stations

Previous studies of Vulcanian eruptive products have shown that the respective volcanic conduits were filled for the most part with low-porosity magma (i.e., < 10 vol%) prior to eruption. Comparison with the theoretical porosity distribution expected from closed-system degassing suggests that gas loss must have taken place at depth within the magmatic column (between 3 and 5 km). At such high pressures

Dense, vitric, dacitic pyroclasts (dacite lithics) from the 1991 preclimactic explosions of Mt. Pinatubo were analyzed for their vesicular and crystal textures and dissolved H2O and CO2 contents. Micron-scale heterogeneities in groundmass glass volatile contents (0.9 wt% differences in H2O within 500 μm) are observed and argue that parts of the dacite lithics equilibrated at different depths before

Ophiolites, found in orogenic belts, are slices of ancient oceanic lithosphere obducted on land during continental collision and ocean closure. They provide valuable insights into submarine volcanological and petrological processes. Palaeotectonic interpretations of ophiolites have heavily depended on geochemical data, despite the considerable submarine alteration and even metamorphism commonly observed

Ebeko is one of the most active volcanoes of the Kurile island arc, producing frequent mild Vulcanian explosions with eruption clouds up to 5 km high. The volcano poses a serious threat to the Severo-Kurilsk town with a population of around 2500 inhabitants, located at a distance of only 7 km on a fan of the volcano’s laharic deposits. Here, we report an overview of the activity of the volcano in the

The South Sandwich Volcanic Arc is one of the most remote and enigmatic arcs on Earth. Sporadic observations from rare cloud-free satellite images—and even rarer in situ reports—provide glimpses into a dynamic arc system characterised by persistent gas emissions and frequent eruptive activity. Our understanding of the state of volcanic activity along this arc is incomplete compared to arcs globally

The Marsili Seamount (Tyrrhenian Sea, Italy) is the largest submarine volcano in the Mediterranean Sea, located in the middle of the Marsili Basin, facing the Calabrian and Sicilian coasts on its eastern side, and the coasts of Sardinia on the opposite side. It has erupted in historical times, and its summit crest is affected by widespread hydrothermal activity. This study looks at mass failures taking

Stromboli is an active, open conduit mafic volcano, whose persistent mild Strombolian activity is occasionally punctuated by much stronger explosions, known as paroxysms. During summer 2019, the volcano unexpectedly produced one such paroxysm on July 3, followed by intense explosive and intermittent effusive activity culminating in a second paroxysm on August 28. Visual observations and the analysis

During volcanic eruptions, the interaction of magma and groundwater can produce thermohydraulic explosions capable of significantly increasing the eruption energy. The most well-known mechanism by which explosive magma–water interactions occur, molten fuel–coolant interaction (MFCI), is a complex series of macro- and microscale processes which have been simulated using laboratory-scale experiments

71 Gulch Volcano, located in the western Snake River Plain, southwestern Idaho (USA), was formed by a basaltic fissure eruption into Pliocene Lake Idaho. Deposits at and below the eruptive surface record the nature of explosive and non-explosive sediment-magma and water-magma interactions. The paleoenvironment and the volcanic plumbing system of 71 Gulch eruption were reconstructed from a detailed

The behavior of magma as it encounters unconsolidated sediment can be studied in fortuitous exposures of incised volcanic systems to help determine the conditions that control the transport, arrest, or mingling of that magma in the sediment. The Pliocene subaqueous basaltic fissure at 71 Gulch, Idaho, USA contains unusual light-colored glassy mingled clasts that were produced through the incorporation

Azufral (SW Colombia) is a dangerous silicic volcano hosting a crater lake, which serves as an excellent example of an incipient plug disruption through phreatomagmatism. We studied the youngest succession of dilute pyroclastic density currents (PDCs) onlapping the north-eastern crater rim. Scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy was used to carry out an automated

Magma ascent during silicic dome-forming eruptions is characterized by significant changes in magma viscosity, permeability, and gas overpressure in the conduit. These changes depend on a set of parameters such as ascent rate, outgassing and crystallization efficiency, and magma viscosity, which in turn may influence the prevailing conditions for effusive versus explosive activity. Here, we combine

Hydrothermal eruptions are characterised by violent explosions ejecting steam, water, mud, and rock. They pose a risk to tourism and the operation of power plants in geothermal areas around the world. Large events with a severe destructive threat are often intensified by the injection of magmatic fluids along faults and fractures within volcano-tectonic rifting environments, such as the Taupo Volcanic

We have used a three-dimensional, non-equilibrium multiphase flow numerical model to simulate subplinian eruption scenarios at La Soufrière de Guadeloupe (Lesser Antilles, France). Initial and boundary conditions for computer simulations were set on the basis of independent estimates of eruption source parameters (i.e. mass eruption rate, volatile content, temperature, grain size distribution) from

The incorporation of snow and ice by pyroclastic density currents (PDCs) can generate mixed-avalanches and pose significant hazards at snow-clad volcanoes. Commonly, the poor preservation of these thin deposits, combined with the subtle characteristics of PDC-snow interaction, has limited their recognition in the geological record. A small-volume (2.5 × 105 m3), basaltic-andesite, mixed-avalanche deposit

New stratigraphic, lithological and petrographic analyses of La Poruña scoria cone (21° 53′ S-68° 30′ W, Central Andes, northern Chile) allow the reconstruction of the eruptive sequence of this monogenetic cone. Petrographic and lithological characteristics allow us to identify three main lithostratigraphic units at La Poruña scoria cone. The first unit consists of agglutinated lapilli, spatter beds

In historic times, two catastrophic fissure eruptions originated in the Eastern Volcanic Zone of Iceland, known as Eldgjá eruption (934–940 CE) and Laki eruption (1783–1784 CE). Eldgjá produced 19.7 km3 of lava flows and 1.3 km3 of tephra; Laki emitted 14.7 km3 of lavas and 0.4 km3 of tephra. They released 232 and 122 megatons of SO2 into the atmosphere, respectively. Abundant historic descriptions

Makushin stratovolcano, Alaska, produced three, highly explosive, andesitic eruptions between ~ 9292 and 6215 yBP. Those eruptions are informally named the CFE (“crater-forming eruption”), Nateekin, and Driftwood Pumice, and they deposited significant tephra fallout in the present-day port of Dutch Harbor and City of Unalaska area. The focus of this study is to examine the geochemistry and petrology

We present a revised stratigraphy of the proximal deposits around Ohachidaira volcano and their paleomagnetic directions obtained from 21 sites (193 samples). We identify four proximal pyroclastic members from Ohachidaira volcano that were produced after the early edifice-building effusive volcanism, from older to younger: (1) vent-opening mafic pyroclastic density current (PDC) deposits (Kobachidaira

In this companion study to Simons et al. (Bull Volcanol 82, 2020a), we examine Strombolian style explosive activity at Yasur (Vanuatu) over 11 weeks via seismic, thermal-infrared and visual observations. In part 1 of this study (Simons et al., Bull Volcanol 82, 2020a), we investigated the link between variations in the surface expression and style of volcanism at Yasur in relation to vent, shallow

In continental arcs, the exposure of primitive eruptive products at the surface is typically a result of rapid magmatic transfer through the crust. As a result, the initially primitive magma experiences minimal crustal residence and thus insignificant differentiation towards more evolved products. This rapid transfer of primitive magma through thickened crust is commonly recorded from smaller, monogenetic