Rapid magma ascent beneath La Palma revealed by seismic tomography

Data availability The seismic catalogue of IGN is publicly available at: https:// www. ign. es/ web/ ign/ portal/ sis- catal ogo- terre motos. The seismic catalogue of INVOLCAN is available under request to Dr. Luca D’Auria ([email protected]). The LOTOS code is publicly available at: www. ivan- art. com/ scien ce/ LOTOS. An online version of the code with the La Palma dataset is available in: Koulakov Ivan. (2022). Data and program codes to reproduce the results of seismic tomography for La Palma Island [Data set]. Zenodo. https:// doi. org/ 10. 5281/ zenodo. 65893 67. The digital elevation model used in all figures and historical lava flows of Figs. 1 and 3 were downloaded from the public graphic repository of GrafCan (www. grafc an. es). The 2021 lava flow was downloaded from the European agency Copernicus Emergency Management Service (httts://emergency.copernicus.eu/mapping/list-of-components/ EMSR546). The software used to generate Fig. 1, Figs. S1, S2 and S3 was QGIS 3.22 (https:// www. qgis. org). The software used to generate Figs. 3, 4 and 6, Figs. S4, S5 and S6 is the LOTOS code.Acknowledgements JP and JMI were partially supported by the FEMALE project of the Spanish Government (Grant No. PID2019-106260GB-I00). IK was supported by the Russian Science Foundation (Grant No. 20-17-00075). The INVOLCAN team was supported by the projects VOLRISKMAC II (MAC2/3.5b/328), co-financed by the EC Cooperation Transnational Program MAC 2014-2020, and “Cumbre Vieja Emergencia”, financed by the Spanish Ministry of Science and Innovation. English language editing was performed by Tornillo Scientific, UK.Supplementary Information The online version contains supplementary material available at https://doi.org/10.1038/s41598-022-21818-9.For the first time, we obtained high-resolution images of Earth's interior of the La Palma volcanic eruption that occurred in 2021 derived during the eruptive process. We present evidence of a rapid magmatic rise from the base of the oceanic crust under the island to produce an eruption that was active for 85 days. This eruption is interpreted as a very accelerated and energetic process. We used data from 11,349 earthquakes to perform travel-time seismic tomography. We present high-precision earthquake relocations and 3D distributions of P and S-wave velocities highlighting the geometry of magma sources. We identified three distinct structures: (1) a shallow localised region (< 3 km) of hydrothermal alteration; (2) spatially extensive, consolidated, oceanic crust extending to 10 km depth and; (3) a large sub-crustal magma-filled rock volume intrusion extending from 7 to 25 km depth. Our results suggest that this large magma reservoir feeds the La Palma eruption continuously. Prior to eruption onset, magma ascended from 10 km depth to the surface in less than 7 days. In the upper 3 km, melt migration is along the western contact between consolidated oceanic crust and altered hydrothermal material.FEMALE project of the Spanish Government (Grant No. PID2019-106260GB-I00)Russian Science Foundation (Grant No. 20-17-00075)INVOLCAN team was supported by the projects VOLRISKMAC II (MAC2/3.5b/328)EC Cooperation Transnational Program MAC 2014-2020Spanish Ministry of Science and Innovatio

Shaking earth: Non-linear seismic processes and the second law of thermodynamics: A case study from Canterbury (New Zealand) earthquakes

We would like to express our gratitude to GeoNet for making available the data used in this work. This work was partially sup-ported by the RNM104 and RNM194 (Research Groups belonging to Junta de Andalucia, Spain) , the Spanish National Projects [grant project PID2019-109608GB-I00] , and the Junta de Andalucia Project [grant project A-RNM-421-UGR18] . English language editing was performed by Tornillo Scientific.Earthquakes are non-linear phenomena that are often treated as a chaotic natural processes. We propose the use of the Second Law of Thermodynamics and entropy, H, as an indicator of the equilibrium state of a seismically active region (a seismic system). In this sense, in this paper we demonstrate the exportability of first principles (e.g., thermodynamics laws) to others scientific fields (e.g., seismology). We suggest that the relationship between increasing H and the occurrence of large earthquakes reflects the irreversible transition of a system. From this point of view, a seismic system evolves from an unstable initial state (due to external stresses) to a state of reduced stress after an earthquake. This is an irreversible transition that entails an increase in entropy. In other words, a seismic system is in a metastable situation that can be characterised by the Second Law of Thermodynamics. We investigated two seismic episodes in the Canterbury area of New Zealand: the 2010 Christchurch earthquake (M = 7.2) and the 2016 Kaikoura earthquake (M = 7.8). The results are remarkably in line with our theoretical forecasts. In other words, an earthquake, understood as an irreversible transition, must results in an increase in entropy.Research Groups belonging to Junta de Andalucia, Spain RNM104- RNM194Spanish National Projects PID2019-109608GB-I00Junta de Andalucia A-RNM-421-UGR1

High variability of interaction energy between volcanic particles: implications for deposit stability

Landslides on the flanks of stratovolcanoes can significantly modify the structure of the volcano. Macroscopic factors that determine the stability of volcanic deposits are well understood, but the microscopic interactions between particles and their impact on deposit cohesion remain poorly understood. Deposit cohesion is related to the energy of interaction between particles, and its calculation depends on the surficial properties of the eruptive materials. The purpose of this study was to perform a preliminary comparative analysis of the surficial properties of volcanic materials from various tectonic settings, including elec‑ trical (zeta potential) and thermodynamic (surface free energy) components and to calcu‑ late the total interaction energy between particles under different environmental conditions. We analyzed samples of eruptive materials obtained from volcanic flows characteristic of six active volcanoes (El Hierro, Pico Do Fogo, Vulcano, Stromboli, Mt. Etna, and Decep‑ tion Island). The results show that deposit cohesion varies among volcanoes and changes drastically with the pH of the medium. Among the volcanic systems investigated, El Hierro (pH = 3) has the most cohesive materials, while Mt. Etna (pH = 8) has the least cohesive materials. Our results suggest that microscopic electrical and thermodynamic properties play a role in the stability of volcanic deposits, and confirm the need for a greater research focus in this area.Universidad de Jaen/CBUASpanish MINECO Project FEMALE PID2019-106260GB-I00Universidad de Jae

Atenuación sísmica de corto periodo en la región de Nuevo Cuyo

A partir de una selección de aproximadamente 400 sismos con profundidades focales entre 0 y 300 km y distancias epicentrales de hasta 400 km se realiza un estudio comparativo de atenuación sísmica en el intervalo 1-12 Hz en la región limitada por 26.5°S - 35.5°S y 63.5°W - 74°W. Utilizando el método del Ensanchamiento del Primer Pulso para ondas P, el método de Normalización de la Coda para ondas S y el modelo de Back-scattering Simple para ondas coda se determinan valores del factor de calidad Qp, Qd y Qc respectivamente. Se presenta una separación preliminar de la atenuación intrínseca (Q.) y de scattering (Q) a partir de los valores obtenidos de Qd y Qc Ajustando una ley de potencia, Q=Qofn, a los valores promedio de Qc se obtienen 22 < Qo < l06,0.9 < /? < l .4 para profundidades focales de hasta 50 km y 33 < ¡2o < 167, 0.7 < n < 1.2 para focos por debajo de 50 km, variando según el lapso de tiempo de coda analizado. El valor medio de Qd depende claramente de la profundidad focal y la frecuencia, con Qo igual a 90 o 160 para focos superficiales o intermedios respectivamente y un n cercano a 0.7 en ambos casos. La relación Q^/Qf varía entre 0.6 y 1.9 en las frecuencias centrales del intervalo estudiado. Los resultados obtenidos indican que la Región de Nuevo Cuyo tiene una atenuación sísmica mayor a la determinada por estudios previos, corroborando que debido a su intensa actividad tectónica, se incluye entre las zonas de alta peligrosidad sísmica del mundo.From a selection of about 400 earthquakes with focal depths between 0 and 300 km and up to 400 km of epicentral distance, a comparative attenuation study is performed for frequencies between 1 and 12 Hz in the region that extends from 26.5° S to 35.5° S and from 63.5° W to 74° W. Applying the Broadening of the First Pulse method for P-waves, Coda Normalization method for S-waves and Single Back-Scattering model for coda-waves, quality factors Qp, Qd and Qc are obtained respectively. A preliminary separation of intrinsic (Q) and scattering (Qs) attenuation is presented from Qd and Qc values. Fitting a powerlaw, Q=Qofn, to <2cmean values, they were found to be 22 < Qo < l06,0.9 < /? < l .4 for focal depths above 50 km and 33 < ¡2o < 167, 0.7 < n < 1.2 for focal depths below 50 km, varying with the considered coda lapse-time. Qd mean value clearly depends on focal depths and frequency, with Qo equal to 90 or 160 for surface or intermediate focal depths respectively and n around 0.7 in both cases. The Q^/Qf ratio varies between 0.6 and 1.9 at the center of the studied frequency range. Obtained results point out greater attenuation than previously determined in Nuevo Cuyo Region, corroborating that due to its intense tectonic activity it is among the high seismic hazard zones of the world.Material digitalizado en SEDICI gracias a la colaboración de la Facultad de Ciencias Astronómicas y Geofísicas (UNLP).Asociación Argentina de Geofísicos y Geodesta

Multi-station volcano tectonic earthquake monitoring based on transfer learning

This study was partially supported by the Spanish FEMALE (PID 2019-106260GB-I00) and PROOF-FOREVER (EUR2022.134044) projects. This work has been partially supported by the project EUR 2022-134044 founded by MCIN/AEI/10.13039/501100011033 in the framework PROYECTOS "EUROPA EXCELENCIA" 2022, CORRESPONDIENTES AL PROGRAMA ESTATAL PARA AFRONTAR LAS PRIORIDADES DE NUESTRO ENTORNO, SUBPROGRAMA ESTATAL DE INTERNACIONALIZACION, DEL PLAN ESTATAL DE INVESTIGACION CIENTIFICA, TECNICA Y DE INNOVACION PARA EL PERIODO 2021-2023, EN EL MARCO DEL PLAN DE RECUPERACION TRANSFORMACION Y RESILIENCIAthe. English language editing was performed by Tornillo Scientific.Introduction: Developing reliable seismic catalogs for volcanoes is essential for investigating underlying volcanic structures. However, owing to the complexity and heterogeneity of volcanic environments, seismic signals are strongly affected by seismic attenuation, which modifies the seismic waveforms and their spectral content observed at different seismic stations. As a consequence, the ability to properly discriminate incoming information is compromised. To address this issue, multi-station operational frameworks that allow unequivocal real-time management of large volumes of volcano seismic data are needed.Methods: In this study, we developed a multi-station volcano tectonic earthquake monitoring approach based on transfer learning techniques. We applied two machine learning systems-a recurrent neural network based on long short-term memory cells (RNN-LSTM) and a temporal convolutional network (TCN)-both trained with a master dataset and catalogue belonging to Deception Island volcano (Antarctica), as blind-recognizers to a new volcanic environment (Mount Bezymianny, Kamchatka; 6 months of data collected from June to December 2017, including periods of quiescence and eruption).Results and discussion: When the systems were re-trained under a multi correlation-based approach (i.e., only seismic traces detected at the same time at different seismic stations were selected), the performances of the systems improved substantially. We found that the RNN-based system offered the most reliable recognition by excluding low confidence detections for seismic traces (i.e., those that were only partially similar to those of the baseline). In contrast, the TCN-based network was capable of detecting a greater number of events; however, many of those events were only partially similar to the master events of the baseline. Together, these two approaches offer complementary tools for volcano monitoring. Moreover, we found that our approach had a number of advantages over the classical short time average over long time-average (STA/LTA) algorithm. In particular, the systems automatically detect VTs in a seismic trace without searching for optimal parameter settings, which makes it a portable, scalable, and economical tool with relatively low computational cost. Moreover, besides obtaining a preliminary seismic catalog, it offers information on the confidence of the detected events. Finally, our approach provides a useful tentative label for subsequent analysis carried out by a human operator. Ultimately, this study contributes a new framework for rapid and easy volcano monitoring based on temporal changes in monitored seismic signals.Spanish FEMALE project PID 2019-106260GB-I00Spanish PROOF-FOREVER project EUR2022.134044MCIN/AEI EUR 2022-13404

Numerically Calculated 3D Space-Weighting Functions to Image Crustal Volcanic Structures Using Diffuse Coda Waves

Seismic coda measurements retrieve parameters linked to the physical characteristics of rock volumes illuminated by high frequency scattered waves. Space weighting functions (SWF) and kernels are different tools that model the spatial sensitivity of coda envelopes to scattering and absorption anomalies in these rock matrices, allowing coda-wave attenuation (Qcoda) imaging. This note clarifies the difference between SWF and sensitivity kernels developed for coda wave imaging. It extends the SWF previously developed in 2D to the third dimension by using radiative transfer and the diffusion equation, based on the assumption that variations of Qcoda depend solely on variations of the extinction length. When applied to active data (Deception Island, Antarctica), 3D SWF images strongly resemble 2D images, making this 3D extension redundant. On the other hand, diffusion does not efficiently model coda waveforms when using earthquake datasets spanning depths between 0 and 20 km, such as at Mount St. Helens volcano. In this setting, scattering attenuation and absorption suffer tradeoffs and cannot be separated by fitting a single seismogram energy envelope for SWF imaging. We propose that an approximate analytical 3D SWF, similar in shape to the common coda kernels used in literature, can still be used in a space weighted back-projection approach. While Qcoda is not a physical parameter of the propagation medium, its spatially-dependent modeling allows improved reconstruction of crustal-scale tectonic and geological features. It is even more efficient as a velocity independent imaging tool for magma and fluid storage when applied to deep volcanism.This research was partly supported by the Projects TEC2015-68752 (MINECO/FEDER), TEC2015-68752 (KNOWAVES)

Atenuación de ondas coda y Lg en el sur de España y de Italia a partir de sismogramas digitales

Reducción altaUniv. de Granada. Leída en 199

Local Earthquake Seismic Tomography Reveals the Link Between Crustal Structure and Volcanism in Tenerife (Canary Islands)

IK was supported by the Russian Science Foundation (Grant 20-17-00075). The INVOLCAN team was supported by the projects VOLRISKMAC II (MAC2/3.5b/328) and co-financed by the Interreg-MAC EU program TFvolcano projects, financed by the Instituto Tecnológico y de Energías Renovables (ITER). JP and JMI were partially supported by the Spanish FEMALE project (PID2019-106260GB-I00) and PROOF-FOREVER project. SA was supported by the project FWZZ- 2022.0017. We also acknowledge Rubén García-Hernández, David Martínez van Dorth, Victor Ortega, Monika Przeor, and the countless persons who contributed to the seismic data analysis and the maintenance of the seismic network of Tenerife. Funding for open access charge: Universidad de Granada/CBUA.Volcanic activity on Tenerife Island is extremely diverse. Three radial rift zones are characterized by cinder cones from basaltic fissure eruptions. A triple junction in central Tenerife exhibits a complex of merged, predominantly phonolitic, stratovolcanoes. The Las Cañadas caldera and widespread ignimbrite deposits reveal high explosive potential. We investigated the crustal and upper mantle structure beneath Tenerife using local earthquake data recorded by two dense seismic networks on the island. For our tomographic inversion, we selected >130,000 P- and S-wave arrivals from ∼6,300 events that occurred during seismic unrests in 2004–2005 and 2017–2021. Synthetic tests confirmed that we could robustly resolve seismic velocity structures to ∼20 km depth. In the upper crust (down to ∼7 km) beneath central Tenerife, a prominent high-velocity anomaly represents the rigid core of the volcanic complex; at greater depths, a strong low-velocity anomaly reveals abrupt crustal thickening. Vp and Vs contour lines of 5.2 and 2.85 km/s, respectively, reveal Moho depth variation; crustal thickness beneath Las Cañadas reaches ∼17 km, whereas that beneath other parts of Tenerife is ∼10 km. An anomaly at ∼5 km beneath the caldera with low Vp, low Vs, and high Vp/Vs might be associated with a major phonolitic magma reservoir. Similar anomalies at ∼ sea level may represent shallow magma sources responsible for recent eruptions. Seismicity occurs in a columnar area of high Vp, high Vs, and low Vp/Vs, and may represent hydrothermal fluid migration through brittle media. Based on our results, we constructed a conceptual model of volcanic activity on Tenerife.Russian Science Foundation (Grant 20-17-00075)INVOLCAN team was supported by the projects VOLRISKMAC II (MAC2/3.5b/328) and co-financed by the Interreg-MAC EU program TFvolcano projects, financed by the Instituto Tecnológico y de Energías Renovables (ITER)Spanish FEMALE project (PID2019-106260GB-I00) and PROOF-FOREVER projectProject FWZZ- 2022.0017Funding for open access charge: Universidad de Granada/CBU

Numerically Calculated 3D Space-Weighting Functions to Image Crustal Volcanic Structures Using Diffuse Coda Waves

Seismic coda measurements retrieve parameters linked to the physical characteristics of rock volumes illuminated by high frequency scattered waves. Space weighting functions (SWF) and kernels are different tools that model the spatial sensitivity of coda envelopes to scattering and absorption anomalies in these rock matrices, allowing coda-wave attenuation (Qcoda) imaging. This note clarifies the difference between SWF and sensitivity kernels developed for coda wave imaging. It extends the SWF previously developed in 2D to the third dimension by using radiative transfer and the diffusion equation, based on the assumption that variations of Qcoda depend solely on variations of the extinction length. When applied to active data (Deception Island, Antarctica), 3D SWF images strongly resemble 2D images, making this 3D extension redundant. On the other hand, diffusion does not efficiently model coda waveforms when using earthquake datasets spanning depths between 0 and 20 km, such as at Mount St. Helens volcano. In this setting, scattering attenuation and absorption suffer tradeoffs and cannot be separated by fitting a single seismogram energy envelope for SWF imaging. We propose that an approximate analytical 3D SWF, similar in shape to the common coda kernels used in literature, can still be used in a space weighted back-projection approach. While Qcoda is not a physical parameter of the propagation medium, its spatially-dependent modeling allows improved reconstruction of crustal-scale tectonic and geological features. It is even more efficient as a velocity independent imaging tool for magma and fluid storage when applied to deep volcanism.This research was partly supported by the Projects TEC2015-68752 (MINECO/FEDER), TEC2015-68752 (KNOWAVES)

Analysis of the Different Scenarios of Coach’s Anger on the Performance of Youth Basketball Teams

In spite of the negative effects of anger, coaches are often seen becoming angry during games. This is especially worrying in U18 categories. Thus, the objective of this study was to identify the influence that the coach’s anger has on the performance of a basketball team in competition. For this, an ad hoc observation tool was designed, in which 587 moments of anger from the coaching staff (64 coaches) were recorded in the 24 semi-final and final matches of the Spanish Autonomous Region Team Championships in 2019 and 2020 in the infantil (M = 14 years old) and cadete (M = 16 years old) categories. The results show that, in response to most incidents of coach anger, the performance of the team did not change. Significant differences were identified in some scenarios, with low- or medium-intensity anger targeted at the defence, where the team performance improved. However, anger towards the referee in the last quarter with scores level had a negative influence on the team’s performanceThis work was supported by the Grupo de Educación, Motricidad, e Investigación onubense (HUM643), University of Huelva Grupo de Educación, Motricidad, e Investigación onubense (HUM643), University of Huelva. Federación Andaluza de Baloncest