Volcano generated tsunami recorded in the near source.

Volcano sector collapse and pyroclastic density currents are common phenomena on active volcanoes and potentially a fatal source of tsunami waves which constitute a serious hazard for local as well as distant coastal population. Several examples in recent history, warn us on the urgent need to improve our mitigation counter-actions when tsunamis have volcanic origin. However, instrumental record of tsunami generated by mass movement along a volcano flank are still rare and not well understood yet. Small tsunamis (≤1 m) induced by pyroclastic density currents associated to violent explosions of Stromboli volcano were recorded in near-source conditions (<1.6 km). We show how tsunami waveform remains unaltered regardless of the two orders of variability in the landslide volume and dynamics. This unprecedented record is also providing the lesson to develop unconventional warning strategies necessary when the tsunamigenic source is expected to be very close (<10 minutes) to densely populated coasts and with a limited time to issue an alert based on simulation of wave propagation and inundation.

Magma pressure discharge induces very long period seismicity.

Volcano seismicity is one of the key parameters to understand magma dynamics of erupting volcanoes. However, the physical process at the origin of the resulting complex and broadband seismic signals remains unclear. Syn-eruptive very long period (VLP) seismic signals have been explained in terms of the sudden expansion of gas pockets rising in the liquid melt. Their origin is linked to a magma dynamics which triggers the explosive process occurring before the explosive onset. We provide evidence based on acoustic, thermal, and ground deformation data to demonstrate that VLP signals at Stromboli are generated at the top of the magma column mainly after the explosion onset. We show that VLP amplitude and duration scale with the eruptive flux which induces a decompression of 103-104 Pa involving the uppermost ~ 250 m of the feeding conduit. The seismic VLP source represents the final stage of a ~ 200 s long charge and discharge mechanism the magma column has to release excess gas accumulated at the base of a denser and degassed magma mush. The position of the VLP seismic source coincides with the centroid of the shallow mush plug and tracks elevation changes of the magma free surface.

Using dense seismo-acoustic network to provide timely warning of the 2019 paroxysmal Stromboli eruptions.

Stromboli Volcano is well known for its persistent explosive activity. On July 3rd and August 28th 2019, two paroxysmal explosions occurred, generating an eruptive column that quickly rose up to 5 km above sea level. Both events were detected by advanced local monitoring networks operated by Istituto Nazionale di Geofisica e Vulcanologia (INGV) and Laboratorio di Geofisica Sperimentale of the University of Firenze (LGS-UNIFI). Signals were also recorded by the Italian national seismic network at a range of hundreds of kilometres and by infrasonic arrays up to distances of 3700 km. Using state-of-the-art propagation modeling, we identify the various seismic and infrasound phases that are used for precise timing of the eruptions. We highlight the advantage of dense regional seismo-acoustic networks to enhance volcanic signal detection in poorly monitored regions, to provide timely warning of eruptions and reliable source amplitude estimate to Volcanic Ash Advisory Centres (VAAC).

Ground deformation reveals the scale-invariant conduit dynamics driving explosive basaltic eruptions.

The mild activity of basaltic volcanoes is punctuated by violent explosive eruptions that occur without obvious precursors. Modelling the source processes of these sudden blasts is challenging. Here, we use two decades of ground deformation (tilt) records from Stromboli volcano to shed light, with unprecedented detail, on the short-term (minute-scale) conduit processes that drive such violent volcanic eruptions. We find that explosive eruptions, with source parameters spanning seven orders of magnitude, all share a common pre-blast ground inflation trend. We explain this exponential inflation using a model in which pressure build-up is caused by the rapid expansion of volatile-rich magma rising from depth into a shallow (<400 m) resident magma conduit. We show that the duration and amplitude of this inflation trend scales with the eruption magnitude, indicating that the explosive dynamics obey the same (scale-invariant) conduit process. This scale-invariance of pre-explosion ground deformation may usher in a new era of short-term eruption forecasting.

Long range infrasound monitoring of Etna volcano.

Among ground-based volcano monitoring techniques, infrasound is the only one capable of detecting explosive eruptions from distances of thousands of kilometers. We show how infrasound array analysis, using acoustic amplitude and detection persistency, allows automatic, near-real-time identification of eruptions of Etna volcano (Italy), for stations at distances greater than 500 km. A semi-empirical attenuation relation is applied to recover the pressure time history at the source using infrasound recorded at global scale (>500 km). An infrasound parameter (IP), defined as the product between the number of detections, filtered for the expected back-azimuth of Etna volcano, and range corrected amplitude, is compared with the explosive activity at Etna volcano that was associated with aviation color code RED warnings. This shows that, during favourable propagation conditions, global arrays are capable of identifying explosive activity of Etna 87% of the period of analysis without negative false alerts. Events are typically not detected during unfavourable propagation conditions, thus resulting in a time variable efficiency of the system. We suggest that infrasound monitoring on a global scale can provide timely input for Volcanic Ash Advisory Centres (VAAC) even when a latency of ~1 hour, due to propagation time, is considered. The results highlight the capability of infrasound for near-real-time volcano monitoring at a regional and global scale.

Modeling Volcanic Eruption Parameters by Near-Source Internal Gravity Waves.

Volcanic explosions release large amounts of hot gas and ash into the atmosphere to form plumes rising several kilometers above eruptive vents, which can pose serious risk on human health and aviation also at several thousands of kilometers from the volcanic source. However the most sophisticate atmospheric models and eruptive plume dynamics require input parameters such as duration of the ejection phase and total mass erupted to constrain the quantity of ash dispersed in the atmosphere and to efficiently evaluate the related hazard. The sudden ejection of this large quantity of ash can perturb the equilibrium of the whole atmosphere triggering oscillations well below the frequencies of acoustic waves, down to much longer periods typical of gravity waves. We show that atmospheric gravity oscillations induced by volcanic eruptions and recorded by pressure sensors can be modeled as a compact source representing the rate of erupted volcanic mass. We demonstrate the feasibility of using gravity waves to derive eruption source parameters such as duration of the injection and total erupted mass with direct application in constraining plume and ash dispersal models.

Trasplante dentario autólogo en el sector anterior: presentación de caso clínico / Autologous tooth transplantation in anterior teeth: report of a clinical case

El autotrasplante dentario se refiere al traslado de una pieza dentaria de su alveolo a otro sitio, alveolo post-extracción o alveolo quirúrgico, en la misma persona. El trasplante dentario ha sido practicado durante siglos, pero generalmente fracasaba por complicaciones en la cicatrización, debido a la falta de conocimiento acerca de la etiología de la reabsorción radicular y el control de la infección. Las investigaciones realizadas en los últimos años tornaron predecible el pronóstico del mismo, demostrando buena supervivencia y brindando una alternativa para la rehabilitación ante la pérdida dental en individuos jóvenes y niños

Trasplante dentario autólogo en el sector anterior: presentación de caso clínico / Autologous tooth transplantation in anterior teeth: report of a clinical case

El autotrasplante dentario se refiere al traslado de una pieza dentaria de su alveolo a otro sitio, alveolo post-extracción o alveolo quirúrgico, en la misma persona. El trasplante dentario ha sido practicado durante siglos, pero generalmente fracasaba por complicaciones en la cicatrización, debido a la falta de conocimiento acerca de la etiología de la reabsorción radicular y el control de la infección. Las investigaciones realizadas en los últimos años tornaron predecible el pronóstico del mismo, demostrando buena supervivencia y brindando una alternativa para la rehabilitación ante la pérdida dental en individuos jóvenes y niños(AU)

Effects of chronic elevation of atrial natriuretic peptide and free fatty acid levels in the induction of type 2 diabetes mellitus and insulin resistance in patients with mitral valve disease.

BACKGROUND AND AIMS: The relationship between atrial natriuretic peptide (ANP), increased free fatty acid (FFA) and insulin resistance in patients with mitral valve disease (MVD), a group characterised by elevated atrial pressure and increased ANP levels, is not defined. The present study was performed to evaluate, in MVD patients, the relationship between increased ANP and FFA levels and insulin resistance and the role of mitral valve replacement/repair in ameliorating these metabolic alterations. Conversely, coronary heart disease (CHD) patients were evaluated before and after coronary artery bypass grafting (CABG), since they are known to be insulin resistant in the presence of chronic FFA increase. METHODS AND RESULTS: Fifty MVD patients and 55 CHD patients were studied before and 2 months after surgery and compared with 166 normal subjects. Before surgery, 56% of MVD patients had impaired glucose tolerance or newly diagnosed type 2 diabetes after a standard oral glucose load and this percentage decreased to 46% after surgery. In CHD, impaired glucose tolerance (IGT) or newly diagnosed type 2 diabetic patients were 67% of patients before and after CABG. In MVD, left atrial (LA) volume, ANP, FFA incremental area and insulin levels were higher and Insulin Sensitivity (IS) index significantly reduced while after surgery, LA volume, ANP and FFA significantly decreased and IS index significantly improved. In CHD, insulin resistance and hyperinsulinaemia were present both before and after surgery with increased tumour necrosis factor (TNF)-α and interleukin (IL)-6 levels. CONCLUSION: In MVD, a higher degree of abnormal glucose tolerance and insulin resistance are associated to increased levels of ANP and FFA, while these metabolic alterations are improved by mitral valve replacement/repair surgery. Clinical Trial.gov registration number NCT 00520962.