Magdalena Oryaëlle Chevrel

Institute of Research for Development | IRD · 163 - Magmas and Volcanoes Laboratory (LMV)

Following an unprecedented seismic activity that started in May 2018, a new volcanic edifice, now called Fani Maoré, was constructed on the ocean floor 50 km east of the island of Mayotte (Indian Ocean). This volcano is the latest addition to a volcanic chain characterized by an alkaline basanite-to-phonolite magmatic differentiation trend. Here, w...

The “Fani Maoré” eruption off the coasts of Mayotte has been intensively monitored by applying methods similar to those used for subaerial eruptions. Repeated high-resolution bathymetric surveys and dredging, coupled with petrological analyses of time-constrained samples, allowed tracking the evolution of magma over the whole submarine eruptive seq...

Emplacement dynamics of highly viscous, silicic lava flows remain poorly constrained due to a lack of consideration of crystal-rich cases. Emplacement models mostly apply to glassy or microlitic, vesiculated rhyolitic flows. However, crystalline, vesicle-free silicic lava can flow differently. We studied the Grande Cascade unit, which is a vesicle-...

Effective and rapid effusive crisis response is necessary to mitigate the risks associated with lava flows that could threaten or inundate inhabited or visited areas. At Piton de la Fournaise (La Réunion, France), well-established protocols between Observatoire Volcanologique du Piton de la Fournaise - Institut de Physique du Globe de Paris (OVPF-I...

Since 1979, Piton de la Fournaise (La Réunion) has erupted on average two times per year, with 95 % of these eruptions occurring within an uninhabited caldera. However, lava flows have occasionally impacted populated regions on the island, as in 1977 and 1986. Since 2014, an integrated satellite data–driven multinational response to effusive crises...

Classical mechanisms of volcanic eruptions mostly involve pressure buildup and magma ascent towards the surface1. Such processes produce geophysical and geochemical signals that may be detected and interpreted as eruption precursors1–3. On 22 May 2021, Mount Nyiragongo (Democratic Republic of the Congo), an open-vent volcano with a persistent lava...

The complexity of understanding volcanic risk is partly due to the fact that it is the result of different hazards, some of which are directly linked to the eruptive activity, such as, gas, lava flows, pyroclastic flows and ash fallout, and others which are directly or indirectly induced by these hazards, such as, debris avalanches, tsunamis, mudfl...

The stabilized channel is a crucial element of an ‘a‘ā flow system, delivering lava to forward extending zones of dispersed flow. However, the term stable implies that channel geometries, lava properties, and dynamics are invariable. However, just how stable are these in space and time? To answer this question, we constrain the degree of variation...

Forest destruction by ‘a‘ā lava flow is common. However, mechanical and thermal interactions between the invading lava and the invaded forest are poorly constrained. We complete mapping, thermal image and sample analyses of a channel-fed ‘a‘ā lava flow system that invaded forest on the NE flank of Mt. Etna (Italy) in 2002. These lava flows destroye...

Formalised elicitation of expert judgements has been used to help tackle several problematic societal issues, including volcanic crises and pandemic threats. We present an expert elicitation exercise for Piton de la Fournaise volcano, La Réunion island, held remotely in April 2021. This involved 28 experts from nine countries who considered a hypot...

L’impact des catastrophes naturelles est devenu une préoccupation forte de nos sociétés modernes. Parmi celles-ci, les éruptions volcaniques sont redoutées pour leurs effets dévastateurs locaux, régionaux ou globaux. Depuis le début du XXe siècle une expertise scientifique s’est progressivement développée visant à évaluer les aléas de l’activité vo...

Popocatépetl, one of the most hazardous volcanoes worldwide, poses significant threats for nearby populations in central Mexico. Therefore, it is important to reconstruct its eruptive history, including estimates of lava-flow emplacement times and their rheological properties. These studies define possible future eruptive scenarios and are necessar...

Peer-reviewed publications are the most common way of sharing scientific knowledge internationally. Volcanica is the only fully diamond open access journal in volcanology, publishing peer-reviewed articles without costs to authors or readers. As part of our wider journal mission, Volcanica also aims to address some of the biggest barriers in resear...

Piton de la Fournaise, situated on La Réunion island (France), is one of the most active hot spot basaltic shield volcanoes worldwide, experiencing at least two eruptions per year since the establishment of the volcanological observatory in 1979. Eruptions are typically fissure-fed and form extensive lava flow fields. About 95 % of some ∼ 250 histo...

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-spat...

Piton de la Fournaise, situated on La Réunion Island (France), is one of the most active hot spot basaltic shield volcanoes worldwide, experiencing at least two eruptions per year since the establishment of the observatory in 1979. Eruptions are typically fissure-fed and form extensive lava flow fields. About 95 % of some ~250 historical events (si...

Given the high eruption recurrence in the Michoacán-Guanajuato volcanic field (MGVF) in central Mexico, the birth of a new monogenetic volcano can be expected in the future. It is important, therefore, to reconstruct the past eruptions of its many different volcanoes, including estimates of lava flow emplacement times and their rheological properti...

In March 2020, the coronavirus disease 2019 outbreak was declared a pandemic by the World Health Organization and became a global health crisis. Authorities worldwide implemented lockdowns to restrict travel and social exchanges in a global effort to counter the pandemic. In France, and in French overseas departments, the lockdown was effective fro...

Low elevation flank eruptions represent highly hazardous events due to their location near, or in, communities. Their potentially high effusion rates can feed fast moving lava flows that enter populated areas with little time for warning or evacuation, as was the case at Nyiragongo in 1977. The January-March 1974 eruption on the western flank of Mo...

Because many volcanoes are densely vegetated, understanding of the interactions between active lava flows and trees is essential for robust hazard modeling. Tree molds − lava flow features generated when advancing lava engulfs and combusts trees − are widely documented but have, to date, only been described qualitatively. Detailed, quantitative stu...

Understanding the thermo-rheological regime and physical character of lava while it is flowing is crucial if we are to adequately model lava flow emplacement dynamics. We present measurements from simultaneous sampling and thermal imaging across the full width of an active channel at Piton de la Fournaise (La Réunion, France). Our data set involves...

Vulcano Fossa's fumarole field (Italy) has been active for more than a century and has become a well‐studied benchmark for fumarolic degassing, often being considered the “model” hydrothermal system. Satellite thermal monitoring is increasingly being used to monitor such systems, so we here use Vulcano to test a new method for assessing heat flux a...

Emplacement of silicic lava flows has rarely been observed. To constrain their dynamics, we need to analyze past flows. The study of structures and textures, at macro- and micro-scale, allow us to reconstruct the history of a lava flow. Structures such as folds and faults are used to infer the state (ductile versus brittle) of the lava at a given t...

Many scientists who have worked on active lava flows or attempted to model lava flows have recognized the importance of rheology in understanding flow dynamics. Numerous attempts have been made to estimate viscosity using flow velocities in active lava channels. However, this only gives a bulk or mean value, applies to channelized flow, and the nee...

To examine whether there was any physical or thermal interaction between trees and lava when a lava flow inundates a forest, we studied the Kīlauea’s July 1974 lava flow. We mapped the location of ∼ 600 lava-trees and the lava type (pāhoehoe versus ‘a‘ā), and sampled an additional ten lava-trees for chemical and textural analysis to infer flow visc...

Silicic lava flows are a rarely observed style of volcanism for which emplacement models remain poorly constrained. Yet they represent a hazard where oversteeping flow fronts can collapse and generate block-and-ash flows as at Santiaguito (Guatemala) in 1929, 1973 and 1986, Unzen (Japan) in 1991, and Sinabung (Indonesia) in 2014. Here we focus on t...

Viscosity is one of the most important physical properties controlling lava flow dynamics. Usually, viscosity is measured in the laboratory where key parameters can be controlled but can never reproduce the natural environment and original state of the lava in terms of crystal and bubble contents, dissolved volatiles, and oxygen fugacity. The most...

Viscosity is one of the most important physical properties controlling lava flow dynamics. Usually, viscosity is measured in the laboratory where key parameters can be controlled but can never reproduce the natural environment and original state of the lava in terms of crystal and bubble contents, dissolved volatiles, and oxygen fugacity. The most...

The Zacapu lacustrine basin is located in the north-central part of the Michoacán-Guanajuato volcanic field (MGVF), which constitutes the west-central segment of the Trans-Mexican Volcanic Belt. Geological mapping of a 395 km² quadrangle encompassing the western margin of the basin, ⁴⁰Ar/³⁹Ar and ¹⁴C radiometric dating, whole-rock chemical and petr...

Lava flow advance can be modeled through tracking the evolution of the thermo-rheological properties of a control volume of lava as it cools and crystallizes. An example of such a model was conceived by Harris and Rowland (2001) who developed a 1-D model, FLOWGO, in which the velocity of a control volume flowing down a channel depends on rheologica...

Channel-fed lava flow systems lack detailed thermal and textural studies through the boundary between channelized and dispersed flow, and out to the flow front. Here, chemical, textural and morphological analyses were made to define cooling and crystallisation rates down the entire system, especially through the zone of dispersed flow. We compare t...

Raman spectrometers will form a key component of the analytical suite of future planetary rovers intended to investigate geological processes on Mars. In order to expand the applicability of these spectrometers and use them as analytical tools for the investigation of silicate glasses, a database correlating Raman spectra to glass composition is cr...

Data Set S2

Table S1

Data Set S1

Supporting Information S1

We present a study on the systematic changes of Raman spectra of a series of glasses as a function of their chemistry. These glass compositions are considered as analogues for rock materials identified on Mars. We performed a diffusion experiment between an iron-rich basaltic and a rhyolitic melt under reducing conditions to produce a wide range of...

To develop Raman spectroscopy as a quantitative tool in both geosciences and planetary sciences the effect of iron oxidation state (Fe3+/Fetot) on the Raman spectra of basaltic and pantelleritic glasses has been investigated. We have used remelted pantellerite from Pantelleria Island and synthetic iron-rich basaltic glasses [from Chevrel et al. (20...

Medium-sized volcanoes, also known as Mexican shields due to their andesitic composition and slightly higher slope angles in comparison to Icelandic shields, occur across the Trans-Mexican Volcanic Belt and represent nearly one third of all volcanic edifices in the Michoacán-Guanajuato Volcanic Field (MGVF). Many questions about their origin and er...

The Michoacán–Guanajuato Volcanic Field is the largest subduction-related monogenetic volcanic field in the world and includes more than 1000 scoria cones and a few hundred medium-sized volcanoes. Although medium-sized volcanoes (domes and shields) are less abundant, hazards associated with the renewal of this type of activity should not be neglect...

Supporting Information

Viscosity has been determined during isothermal crystallization of an andesite from Tungurahua volcano (Ecuador). Viscosity was continuously recorded using the concentric cylinder method and employing a Pt-sheathed alumina spindle at 1 bar and from 1400 ºC to sub-liquidus temperatures to track rheological changes during crystallization. The disposa...

The Michoacán-Guanajuato Volcanic Field in the Trans-Mexican Volcanic Belt contains the largest concentration of monogenetic vents on Earth associated with a subduction-related continental arc, holding more than 1,100 edifices consisting of abundant scoria cones, about 300 “enigmatic” shields, and ~22 maars. Paricutin (1943-1952) is the youngest vo...

In planetary sciences, the emplacement of lava flows is commonly modelled using a single rheological parameter (apparent viscosity or apparent yield strength) calculated from morphological dimensions using Jeffreys' and Hulme's equations. The rheological parameter is then typically further interpreted in terms of the nature and chemical composition...

In planetary sciences, the emplacement of lava flows is commonly modelled using a single rheological parameter (apparent viscosity or apparent yield strength) calculated from morphological dimensions using Jeffreysʼ and Hulmeʼs equations. The rheological parameter is then typically further interpreted in terms of the nature and chemical composition...

The effects of increasing quantities of iron on the viscosity, heat capacity and density of a haplobasaltic base composition (anorthite–diopside 1 atm eutectic) were determined. Super-liquidus viscosity and density were measured in air using the concentric cylinder method and double-bob Archimedean method, respectively. Low-temperature viscosities...

The chemical compositions of martian basalts are enriched in iron with respect to terrestrial basalts. Their rheology is poorly known and liquids of this chemical composition have not been experimentally investigated. Here, we determine the viscosity of five synthetic silicate liquids having compositions representative of the diversity of martian v...

Differences in the chemical compositions of planetary mantles can contribute to the large diversity of volcanic melts. In particular, differences in oxidation state during core-mantle differentiation result in significant variations of iron oxide concentration in the mantle, the most oxidized bodies having the most iron-rich mantles (e.g., Mars). T...

Emplacement of lava flow is function of the effusion rate, the initial topography and the rheology of the erupted magmas. Indeed the rheology of magmas is a key parameter in magma transport processes and volcanic eruptions. In nature, magmas are transient: changes in P-T conditions force the magma to chemically and physically evolve, resolving a tr...

Despite the consensus that TTGs, the main constituents of the Archaean continental crust worldwide, originated by partial melting of garnet-bearing amphibolites, natural evidence is scarce. A large variety of Archaean amphibole-rich rocks, including migmatitic amphibolites and hornblende-rich cumulates, was exhumed as a tectonic melange in the Inyo...

The viscosity of magma strongly influences its rheological behaviour, which is a key determinant of magma trans-port processes and volcanic eruptions. Understanding the factors controlling the viscosity of magma is important to our assessment of hazards posed by active volcanoes. In nature, magmas span a very wide range in viscosity (10 −1 to 10 14...

The rheological properties and emplacement parameters of extra-terrestrial lava flows (effusion rate, yield strength, viscosity), such as those on the Moon and Mars, are commonly derived from their morphology through simple physical models (1). Since observations are mostly limited to remote sensing data (images and topography) with no possible gro...