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

Tracking volcanic explosions using Shannon entropy at Volcán de Colima

The main objective of this work is to show that Shannon Entropy (SE) calculated on continuous seismic signals can be used in a volcanic eruption monitoring system. We analysed three years of volcanic activity of Volcán de Colima, México, recorded between January 2015 and May 2017. This period includes two large explosions, with pyroclastic and lava flows, and intense activity of less energetic explosion, culminating with a period of quiescence. In order to confirm the success of our results, we used images of the Visual Monitoring system of Colima Volcano Observatory. Another of the objectives of this work is to show how the decrease in SE values can be used to track minor explosive activity, helping Machine Learning algorithms to work more efficiently in the complex problem of distinguishing the explosion signals in the seismograms. We show that the two big eruptions selected were forecasted successfully (6 and 2 days respectively) using the decay of SE. We conclude that SE could be used as a complementary tool in seismic volcano monitoring, showing its successful behaviour prior to energetic eruptions, giving time enough to alert the population and prepare for the consequences of an imminent and well predicted moment of the eruption.FEMALE (PID2019-106260GB-I00)PROOF-FOREVER (EUR2022.134044) projectsMinisterio de Ciencia e Innovación del Gobierno de España (MCIN)Agencia Estatal de Investigación (AEI)Fondo Social Europeo (FSE)Programa Estatal de Promoción del Talento y su Empleabilidad en I+D+I Ayudas para contratos predoctorales para la formación de doctores 2020 (PRE2020-092719

From 2D to 3D attenuation tomography in volcanoes: the study of Tenerife (Canary Islands) and Deception Island (Antarctica)

Tesis Univ. Granada. Departamento de Física Teórica y del CosmosEste trabajo ha sido financiado a través del Programa de Ayudas de Formación y Perfeccionamiento de Personal Investigador (BFI09.277), Gobierno Vasco; proyecto CTM2010-11740-E/ANT del Ministerio de Ciencia e Innovación; proyectos HISS (CGL2008-01660) y EPHESTOS (CGL2011-29499-C02-01) del Ministerio de Ciencia e Innovación; proyecto MED-SUV (ENV.2012.6.4-2) de la Unión Europea

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

Ambient noise tomography of El Hierro island (Canary Islands)

El Hierro island is one of the most active islands in the Canary Islands from a volcanological point of view. This is the reason why the imaging of the internal crustal structure is of huge importance. The geophysical exploration methods employed on El Hierro Island, such as gravimetry and seismic tomography, allowed obtaining the high-resolution characterization of the crust’s deep part. However, these methods did not yield significant information about the surface and the shallower part of the crust. To gain a deeper insight into the shallow geological structure of El Hierro island, we employed Ambient Noise Tomography to construct a 3D S-wave velocity model. Our investigation revealed the presence of seven significant seismic velocity anomalies, partly identified by previous studies. We identified two high-velocity anomalies located in the eastern and western parts of the island at a depth between 0 and 3 km below sea level (b.s.l.). We interpreted these anomalies as dense intrusive complexes of dikes, possibly linked to the Tanganasoga volcano and the formation of the Tiñor edifice. Additionally, we observed two high-velocity anomalies in the northern and southern parts of the island at a depth between 3 and 4 km b.s.l., which we related to the accumulation of solidified igneous rocks. On the other hand, a low-velocity anomaly was observed in the Golfo valley, between 0 and 0.5 km b.s.l., and we interpreted it as megalandslide deposits. This anomaly was evidenced for the first time in the present study. Finally, two lowvelocity anomalies were observed in the southern part of the island at different depths, between 0–0.5 km b.s.l. and 0–2 km b.s.l. These were interpreted as fractures generated by Quaternary volcanism along the SSE Rift. Also, one of them was evidenced for the first time in this study, corresponding to the zone of the fractures produced during the Quaternary volcanism. This study has allowed us to gain a more detailed understanding of the shallow geological structure of the island. Even if most of the anomalies had been evidenced previously, we could observe the existence of two low-velocity zones in the shallow crust that have not been observed before.Project VOLRISKMAC II (MAC2/3.5b/328)Cabildo Insular de Tenerife (TFassistance