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The eruption of the Tajogaite volcano at the island of La Palma (Canary Islands, Spain) between September and December 2021 generated a huge amount of fallout deposits (tephra), of which there are still accumulations of more than 3 metres thick in sectors close to the cone. During and after the eruption, the tephra has been remobilised, both by anthropic actions of removal from buildings, roads and other infrastructures, and by natural processes due to volcanic, aeolian, gravitational and runoff dynamics. Several remobilisation tests were carried out on field to estimate the water remobilisation capacity and prevent possible hazards and risks associated with extreme lahar-type events due to intense rainfall. They consisted on artificial rainfall and concentrated runoff on experimental micro-plots and sectors of slopes and at the bottom of one of the ravines in the southwestern sector of the island (Tamanca ravine). Therefore, it has been possible to estimate which variables (slope, granulometry, type of surface cover) condition both the generation of runoff and the start of remobilisation, as well as some indicative threshold values. Among all the variables, the one that has the greatest influence on the onset of remobilisations is not the slope, as might be expected, but the concentration of runoff on impermeable surfaces (consolidated rocks, anthropised surfaces) or on the branches and stems of shrub and tree vegetation. These results are of practical use for preventive mapping of areas susceptible to suffer remobilisation. They may constitute the input for numerical models simulating the triggering and circulation of non-Newtonian flows on slopes and gullies, from which risk maps for land-use planning and emergency management will be derived. [ABSTRACT FROM AUTHOR]

The seismic crisis that began in May, 2018 off the coast of Mayotte announced the onset of a volcanic eruption that started two months later 50 km southeast of the island. This seismicity has since been taken as an indicator of the volcanic and tectonic activity in the area. In response to this activity, a network of stations was deployed on Mayotte over the past three years. We used the machine learning-based method PhaseNet to re-analyze the seismicity recorded on land since March 2019. We detect 50,512 events compared to around 6508 manually picked events between March 2019 and March 2021. We locate them with NonLinLoc and a locally developed 1-D velocity model. While eruptions are often monitored through the analysis of Volcano-Tectonic (VT) seismicity (2-40 Hz), we focus on the lower frequency, Long Period (LP) earthquakes (0.5-5 Hz), which are thought to be more directly related to fluid movement at depth. In Mayotte, the VT events are spread between two clusters, whereas the LP events are all located in a single cluster in the bigger proximal VT cluster, at depths ranging from 25 to 40 km. Moreover, while the VT earthquakes of the proximal cluster occur continuously with no apparent pattern, LP events occur in swarms that last for tens of minutes. We show that during the swarms, LP events generally migrate downward at a speed of 5 m/s. While these events do not appear directly linked to upward fluid migration, their waveform signature could result from propagation through a fluid-rich medium. They occur at a different location than VT earthquakes, also suggesting a different origin which could be linked to the Very Long Period events (VLP) observed above the LP earthquakes in Mayotte. [ABSTRACT FROM AUTHOR]

Community resilience is a novel construct that allows us to recognize the active role that communities play when facing adversity or collective affectation. That is why this research article aims to analyze the role of community resilience in the face of disasters in a group of inhabitants of the Mapachico community in the center of the city of Pasto. The research was developed from the qualitative paradigm, the phenomenological approach and the type of ethnomethodological study. The results show that the components of collective self-esteem, cultural identity and solidarity favor the reconstruction of the social fabric and shape perceptions of risk, while social humor is emerging as an opportunity to generate community resistance processes. As a conclusion, it can be said that community resilience is expressed as a characteristic that allows the integration and identification of members in social development issues. [ABSTRACT FROM AUTHOR]

Volcanic eruptions produce health changes in animals that may be associated with emitted gases and deposited ashes. We evaluated whether the Puyehue–Cordón Caulle volcanic eruption in 2011 produced health changes in the threatened Andean Condor (Vultur gryphus) living in the area most affected by the eruption, northwestern Patagonia. We studied clinical and biochemical parameters of condors examined before and after the eruption. We also examined concentrations of different metals and metalloids in the blood of individuals sampled after the eruption. The most common clinical abnormality associated with the eruptive process was irritating pharyngitis. In condors sampled after the eruption, blood concentrations of albumin, calcium, carotenoids, and total proteins decreased to levels under the reference values reported for this species. We found different chemical elements in the blood of these condors after the eruption, such as arsenic and cadmium, with the potential to produce health impacts. Thus, the health of Andean Condors was affected in different ways by the eruption; remaining in the affected area appears to have been costly. However, in comparison to other animal species, the health impacts were not as strong and were mainly related to food shortages due to the decrease in availability of livestock carcasses linked to the eruption. This suggests that condors dealt relatively well with this massive event. Future research is needed to evaluate if the health changes we found reduce the survival of this species, and if the cost of inhabiting volcanic areas has any ecological or evolutionary influence on the condor's life history. [ABSTRACT FROM AUTHOR]

There are different speeches and practices told by people and government on an important public policy issue such as civil protection. First, in this paper, the notion of risk, according to Social Sciences is reviewed, as well as the civil protection policies. Secondly, the look around the risk around Popocatepetl volcano in Amecameca and some popular narratives that present some distance from the technical scientific discourse are remarked. This is done through some data and results from a survey applied in this place and interviews that were done among the population. The results indicate it is possible to see the distance between the expressions, glances and speeches regarding the volcano risk. [ABSTRACT FROM AUTHOR]

The following work shows a study about the recent activity of the Popocatepetl volcano, analyzing images of the eruptive columns of the same and supported by terrestrial and satellite photogrammetry tools for their classification; the emanation of gases, ashes, height and direction were calculated. After 67 years, on December 21, 1994 the volcano had an eruptive activity. The columns reached up to 3 km altitude, the ash emission increased and the seismometers indicated tremors of the movement of the magma in the structure. This event marked the reactivation of the volcano, this study shows an analysis of the surface and perimeter of the crater, to determine the deformations that it has suffered until 2016 generated by the activity that the volcano has experienced; for this study, satellite images and application of specialized software for its processing were used. [ABSTRACT FROM AUTHOR]

Many Calderonian characters find difficult to keep a secret against the human tendency to complaints and release, as well as external pressures that influence their revelation. Among the many expressions referring to this struggle between contentio and overflow highlights in a special way the volcanic metaphor because of its proliferation, its dramatic strength and remarkable artificiality. This paper examines and classifies a representative number of passages which contain the image in order to glimpse its iconic, conceptual and emotional connections, related to Baroque society and the theoretical framework of secrecy. [ABSTRACT FROM AUTHOR]

Jökulhlaup is the Icelandic term for a sudden and substantial release of subglacial and/or proglacial water. The subglacial volcano Katla and its associated glacier Myrdalsjökull, near Iceland's southern coast, have the potential to cause catastrophic jökulhlaups through geothermally induced melting and volcanic eruptions. The resulting jökulhlaups can cause destruction of property and detriment to human life. Water-filled ice depressions (termed ice cauldrons) are produced by enhanced geothermal heating/melting and are large enough to be identified through remote sensing; therefore, ice cauldrons can be used to infer geothermal hot-spot locations and melt rates. To assess the risk of surrounding communities and infrastructure, a map of geothermal hot spots, loss of glacial mass, and meltwater flow paths of the Myrdalsjökull glacier were created and analysed. Using geospatial analysis, it was determined that three hazard zones -- two towns, Alftaver (to the east) and Vik (to the south), as well as Iceland's main highway, Route 1 -- are directly in the path of potential jökulhlaups originating from the Myrdalsjökull-Katla complex. Future research should further constrain meltwater flow paths to determine potential flow discharge rates and areas that are at the greatest risk of flooding. [ABSTRACT FROM AUTHOR]

The concentrations of numerous elements (Al, As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, V, Zn) have been measured by ICP-MS and AAS in mosses of various sites from Mt. Etna and lblei Mountains, in order to assess metal accumulation levels in regards to different anthropogenic disturbances and volcanic activity. All surveys have been performed by using Hypnum cupressiforme and Scieropodium cespitans; the latter species was used to compare its bioaccumulation capacity with H. cupressiforme, a species that has been extensively used all over Europe to biomonitor heavy metal levels. The concentrations of the same elements were also determined in soil samples collected at the same sites as the mosses to evaluate the role of soil composition as a potential source of metals uptake by mosses. Significant differences in heavy metal concentrations in both mosses species were found across the different sites. The levels found at the pristine sites for all the analyzed elements but Cr were always lower than those affected by anthropogenic sources. Also the varying anthropogenic sources influenced the heavy metal content of both mosses. A close relationship between mosses and soils was found for the following elements: As, Cu, Hg, Mn and Zn, an indication of the influence of re-suspension of soil particulates on the concentrations of these elements in both moss species. Hypnum cupressifornie and Scieropodium cespilans performed almost equally as heavy metal biomonitors since no statistical differences were found for the heavy metal concentrations of both mosses, and no site*moss interactions were recorded. However, S. cespitans was slightly less influenced by soil sources than H. cupressifornie in regards to As, Cu, Hg, Mn and Zn tissue concentrations. Therefore, this study corroborates previous findings on the usefulness of mosses as biomonitors of heavy metals, and highlights the potential use of an additional moss species, S. cespitans. [ABSTRACT FROM AUTHOR]

A new species of the genus Willemia, anophthalma group, W. iztaccihuatlensis n. sp., from the Northwest slope of Iztaccihuatl Volcano is described. It is characterized by absence of the sensilla el on antennal segment IV, post antennal organ (PAO) with eight vesicles and anal spines bigger than all of species known. A comparative table of the anophothalma group with three closer relative species and the new species is given. [ABSTRACT FROM AUTHOR]

EDM is a technique for monitoring volcanic deformation, which may show as changes in the Earth's surface before an eruption. Studies of deformation at Volcan de Colima started towards the end of 1996 and continues to the present in 2009. During this period there has been four volcanic eruptions recorded in the years 1998, 2001, 2004 and 2007. These events were documented using the EDM technique; however, the last two are unclear due to technical problems, which affected the magnitude of the final data. This did not allow a precise diagnosis like in 1998 and 2001. [ABSTRACT FROM AUTHOR]

Abstract: The high activity level of Hybrid Events (HE) detected beneath the Cayambe volcano since 1989 has been more thoroughly investigated with data from a temporary array. The unusual HE spectral content allows separating a high-frequency signal riding on a low-frequency one, with a probable single source. HEs are interpreted as high frequency VT events, produced by the interaction between magmatic heat and an underground water system fed by thaw water from the summital glacier, which trigger simultaneous low-frequency fluid resonance in the highly fractured adjacent medium. Pure VTs are interpreted as ‘aborted’ HEs occurring probably in the oldest and coldest part of the volcano complex. To cite this article: B. Guillier, J.-L. Chatelain, C. R. Geoscience 338 (2006). [Copyright &y& Elsevier]

The drilling of a gallery through the Roche-E´crite massif (Reunion Island) allowed to sample the old formations of the ‘Piton des Neiges’ volcano. The mineralogical study of the alteration products of the formations showed significant variations of the zeolites/clay minerals ratio depending on the location of the rocks in the volcano. The abundance of zeolites in the formation near the surface hydrographic network or the underground water drainage system seems to be due to the physicochemical processes favouring zeolites in more open systems in their competition with secondary clays. To cite this article: L. Bret et al., C. R. Geoscience 335 (2003). [Copyright &y& Elsevier]

The behavior of granular matter depends greatly on the size of its elementary components. Besides the well studied field of granulates made up of large sized particles which ignore the interaction of the particles with the fluid or gas environment, the physics of a collection of tiny particles such as fine or superfine powders concerns a majority of industrial applications. This paper briefly outlines several basic behavior of powders showing that new features come into play when the particle interaction with the surrounding gas is taken into account. It starts from two key mechanisms: the first arises when the typical particle velocity is in the order of the free fall velocity of that particle, which simply means that fluid drag comes into play. The second consists in considering the powder cakes as a porous material. Combining these two basic mechanisms with well-known granulate properties such as avalanching or heaping, leads to previously ignored sets of plugging effects or surface instabilities resulting from what we call the ‘volcano effect’. Furthermore, we show that, up to a certain extent, the physics of fine powders interacting with gas, may mimic the physics of wetting liquids. To cite this article: J. Duran, C. R. Physique 3 (2002) 217–227. [Copyright &y& Elsevier]