61 research outputs found
Small-scale spatial variability of soil CO2 flux: Implication for monitoring strategy
In recent decades, soil CO2 flux measurements have been often used in both volcanic and seismically active areas to investigate the interconnections between temporal and spatial anomalies in degassing and telluric activities. In this study, we focus on a narrow degassing area of the Piton de la Fournaise volcano, that has been chosen for its proximity and link with the frequently active volcanic area. Our aim is to constrain the degassing in this narrow area and identify the potential processes involved in both spatial and temporal soil CO2 variations in order to provide an enhanced monitoring strategy for soil CO2 flux. We performed a geophysical survey (self-potential measurements: SP; electrical resistivity tomography: ERT) to provide a high-resolution description of the subsurface. We identified one main SP negative anomaly dividing the area in two zones. Based on these results, we set ten control points, from the site of the main SP negative anomaly up to 230 m away, where soil CO2 fluxes were weekly measured during one year of intense eruptive activity at Piton de la Fournaise. Our findings show that lateral and vertical soil heterogeneities and structures exert a strong control on the degassing pattern. We find that temporal soil CO2 flux series at control points close to the main SP negative anomaly better record variations linked to the volcanic activity. We also show that the synchronicity between the increase of soil CO2 flux and deep seismicity can be best explained by a pulsed process pushing out the CO2 already stored and fractionated in the system. Importantly, our findings show that low soil CO2 fluxes and low carbon isotopic signature are able to track variations of volcanic activity in the same way as high fluxes and high carbon isotopic signature do. This result gives important insights in terms of monitoring strategy of volcanic and seismotectonic areas in geodynamics contexts characterized by difficult environmental operational conditions as commonly met in tropical areaPublished13-264A. Oceanografia e climaJCR Journa
The validity of parental reports on motor skills performance level in preschool children: a comparison with a standardized motor test.
Motor skills are interrelated with essential domains of childhood such as cognitive and social development. Thus, the evaluation of motor skills and the identification of atypical or delayed motor development is crucial in pediatric practice (e.g., during well-child visits). Parental reports on motor skills may serve as possible indicators to decide whether further assessment of a child is necessary or not. We compared parental reports on fundamental motor skills performance level (e.g., hopping, throwing), based on questions frequently asked in pediatric practice, with a standardized motor test in 389 children (46.5% girls/53.5% boys, M age = 3.8 years, SD = 0.5, range 3.0-5.0 years) from the Swiss Preschoolers' Health Study (SPLASHY). Motor skills were examined using the Zurich Neuromotor Assessment 3-5 (ZNA3-5), and parents filled in an online questionnaire on fundamental motor skills performance level. The results showed that the answers from the parental report correlated only weakly with the objectively assessed motor skills (r = .225, p < .001).
Although a parental screening instrument for motor skills would be desirable, the parent's report used in this study was not a valid indicator for children's fundamental motor skills. Thus, we may recommend to objectively examine motor skills in clinical practice and not to exclusively rely on parental report. What is Known: âą Early assessment of motor skills in preschool children is important because motor skills are essential for the engagement in social activities and the development of cognitive abilities. Atypical or delayed motor development can be an indicator for different developmental needs or disorders. âą Pediatricians frequently ask parents about the motor competences of their child during well-child visits. What is New: âą The parental report on fundamental motor skills performance level used in this study was not a reliable indicator for describing motor development in the preschool age. âą Standardized examinations of motor skills are required to validly assess motor development in preschoolers
Lack of genetic structure and evidence for long-distance dispersal in ash (Fraxinus excelsior) populations under threat from an emergent fungal pathogen: implications for restorative planting
Forecasting an eruption
International audienceFlorent Brenguier, Valerie Ferrazzini and their colleagues braved tropical cyclones and crater collapses while recording continuous seismological data on the Piton de la Foumaise volcano
Eruptive pattern classiïŹcation on Mount Etna (Sicily) and Piton de la Fournaise (La RĂ©union)
In the framework of the European MEDiterrranean Supersite Volcanoes (MEDSUV) project, Mt. Etna (Italy) and Piton de la Fournaise (La RĂ©union) were chosen as âEuropean Supersite Demonstratorâ and test site, respectively, to promote the transfer and implementation of efïŹcient tools for the identiïŹcation of impending volcanic activity. Both are âopen-conduit volcanoesâ, forming ideal sites for the test and validation of innovative concepts, which can contribute to minimize volcanic hazard. OneoftheaimsoftheMED-SUVprojectwasthedevelopmentofsoftwareformachinelearningapplicabletodata processing for early-warning purposes. Near-real time classiïŹcation of continuous seismic data stream has been carried out in the control room of INGV Osservatorio Etneo since 2010. Subsequently, automatic alert procedures were activated. In the light of the excellent results for the 24/7 surveillance of Etna, we examine the portability of tools developed in the framework of the project when applied to seismic data recorded at Piton de la Fournaise. In the present application to data recorded at Piton de la Fournaise, the classiïŹer aims at highlighting changes in the frequency content of the background seismic signal heralding the activation of the volcanic source and the imminent eruption. We describe the preliminary results of this test on a set of data of nearly two years starting on January 2014. This period follows three years of inactivity and deïŹation of the volcano and marks a renewal of thevolcanoactivity withinïŹation,deep seismicity (-7kmbsl) andïŹve eruptions with fountains and lava ïŹowsthat lasted from a few hours to more than two months. We discuss here the necessary tuning for the implementation of the software to the new dataset analyzed. We also propose a comparison with the results of pattern classiïŹcation regarding recent eruptive activity at Etna.PublishedVienna (Austria)2V. Dinamiche di unrest e scenari pre-eruttiviope
Distribution des sĂ©ismes dans lâespace et dans le temps â Coupes nord-sud et est-ouest de la sismicitĂ© sous le Piton de la Fournaise
Coupes nord-sud et est-ouest de la sismicitĂ© sous le Piton de la Fournaise. Les points colorĂ©s indiquent les sĂ©ismes dĂ©clenchĂ©s pendant les 10 premiers jours de remontĂ©e verticale de la sismicitĂ©. Les points gris indiquent les autres sĂ©ismes dĂ©clenchĂ©s en 2014-2015.Avec plus dâune Ă©ruption par an en moyenne, le Piton de la Fournaise est lâun des volcans les plus actifs au monde. Comme sur la plupart des volcans, les Ă©ruptions y sont gĂ©nĂ©ralement prĂ©cĂ©dĂ©es par une abondante activitĂ© sismique. On observe ainsi de vĂ©ritables essaims de micro-sĂ©ismes : des milliers de petits tremblements de terre correspondant Ă autant de petites ruptures dĂ©clenchĂ©es au sein de lâĂ©difice volcanique. Au Piton de la Fournaise, cette activitĂ© est tellement importante quâil devient mĂȘme difficile de dĂ©tecter et de localiser prĂ©cisĂ©ment tous ces signaux en utilisant des procĂ©dures classiques.Pour identifier un maximum de tremblements de terre, les chercheurs ont donc essayĂ© de resserrer les mailles du filet en appliquant de nouvelles mĂ©thodes de dĂ©tection automatique. Les rĂ©sultats furent sans appels avec un grand nombre de sĂ©ismes dĂ©tectĂ©s automatiquement. En Ă©tudiant finement le dĂ©lai temporel entre ces signaux, tous ces sĂ©ismes nouvellement dĂ©tectĂ©s ont Ă©galement pu ĂȘtre localisĂ©s prĂ©cisĂ©ment. A l'occasion de cette Ă©tude, les chercheurs ont dĂ©couvert une remontĂ©e profonde de magma qui correspond au remplissage dâune chambre magmatique superficielle suivie quelques jours plus tard par une Ă©ruption volcanique
Ăvolution de la profondeur des sĂ©ismes sur le Piton de la Fournaise
Chaque point noir correspond Ă un sĂ©isme localisĂ© pendant cette Ă©tude. On observe une migration verticale de la sismicitĂ© profonde en avril 2015.Avec plus dâune Ă©ruption par an en moyenne, le Piton de la Fournaise (RĂ©union) est lâun des volcans les plus actifs au monde. Comme sur la plupart des volcans, les Ă©ruptions y sont gĂ©nĂ©ralement prĂ©cĂ©dĂ©es par une abondante activitĂ© sismique. On observe ainsi de vĂ©ritables essaims de micro-sĂ©ismes : des milliers de petits tremblements de terre correspondant Ă autant de petites ruptures dĂ©clenchĂ©es au sein de lâĂ©difice volcanique. Au Piton de la Fournaise, cette activitĂ© est tellement importante quâil devient mĂȘme difficile de dĂ©tecter et de localiser prĂ©cisĂ©ment tous ces signaux en utilisant des procĂ©dures classiques.Pour identifier un maximum de tremblements de terre, les chercheurs ont donc essayĂ© de resserrer les mailles du filet en appliquant de nouvelles mĂ©thodes de dĂ©tection automatique. Les rĂ©sultats furent sans appels avec un grand nombre de sĂ©ismes dĂ©tectĂ©s automatiquement. En Ă©tudiant finement le dĂ©lai temporel entre ces signaux, tous ces sĂ©ismes nouvellement dĂ©tectĂ©s ont Ă©galement pu ĂȘtre localisĂ©s prĂ©cisĂ©ment. A l'occasion de cette Ă©tude, les chercheurs ont dĂ©couvert une remontĂ©e profonde de magma qui correspond au remplissage dâune chambre magmatique superficielle suivie quelques jours plus tard par une Ă©ruption volcanique
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