Life and Earth Sciences

Volcanology

Understanding our Planet, assessing natural hazards and harnessing georesources are the core mission of the Volcanology Research Group. A bold vision that permeates our applied and discovery research programs. 

The Volcanology group profile page on Digital.CSIC.

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Teide
Presentation

Our research is dedicated to understanding the structure and evolution of the Earth, in particular volcanic and magmatic systems. We study Earth structure and dynamics, in particular lithospheric processes, with a strong focus on rock and magma rheology, fluid-rock interactions and rates of processes. We utilize a wide range of geological and geophysical techniques, along with advanced analytical and numerical methods. We use this knowledge to assess earthquake and volcanic hazards, and to better harness georesources. 

Due to our unique location on the Island of Tenerife (the third largest volcano on Earth), our investigations focus on ocean island volcanism. But, we have a wide range of research interests and we actively work on other type of volcanism and different tectonic settings. 

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Magma dynamics: Generation, transport and eruption

Our research aims to contribute to answer questions on the magma dynamics as: why or at what rate magmas are generated?; how magmas became mobile?; or what controls the stagnation or migration towards the surface before eruptions?

Responsable:

Pablo J. González

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Volcanic processes and hazards

Our group is world leading in the use of satellite radar interferometric (InSAR) for imaging Earth’s surface to measure ground deformation due to a variety of geophysical processes. We develop analytical and numerical models for the propagation and storage of magma.

Responsable:

Pablo J. González

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V3

Geodynamics: Lithosphere-Asthenosphere evolution in space and time

Our research aims at a quantitative understanding of deformation processes affecting the lithosphere (kinematics and rheological laws). It attempts to integrate observation from instantaneous single earthquakes and eruptions to the formation of volcanoes at geological time scale.

Responsable:

Pablo J. González

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Georesources: interaction of rock and fluids in the Earth’s crust

This research line works towards holistic approaches to detect and monitor changes in geological reservoirs, mainly from a geomechanical approach (deformation and fluid flow coupling).

Responsable:

Pablo J. González

Site scale slow moving landslides: characterization by monitoring and modelling

Los deslizamientos de ladera son un peligro natural a nivel global. Pueden ocurrir bajo multitud de condiciones y son capaces de provocar una gran cantidad de pérdidas de vidas humanas e importantes daños económicos. La definición general de deslizamiento incluye una amplia variedad de fenómenos con características y comportamientos mecánicos propios. Entre esta diversidad de tipologías, los deslizamientos lentos de ladera se caracterizan por alcanzar velocidades de hasta varios centímetros/año y porque la rotura se desarrolla a lo largo de planos de cizalla. Pueden llegar a producir un gran impacto en zonas urbanas e infraestructura y ser precursores de movimientos más rápidos y catastróficos.
La heterogeneidad y complejidad de los fenómenos de inestabilidad de laderas exigen una nomenclatura y sistema de clasificación universales que puedan ser utilizados por toda la comunidad científica y técnica. La identificación preliminar del tipo de movimiento y principales características, tanto espaciales como temporales, es fundamental para poder diseñar sistemas de monitorización óptimos y para realizar la hipótesis del sistema a modelar.
Monitorizar los desplazamientos de un deslizamiento sirve para estudiar y controlar su actividad. En la actualidad es posible medir desplazamientos de la superficie terrestre mediante técnicas de teledetección, entre las cuales destaca la interferometría diferencial avanzada radar de satélite (A-DInSAR), que utiliza imágenes radar adquiridas de forma periódica bajo cualquier condición climática y permite monitorizar deformaciones complejas con precisión sub-centimétrica. En este trabajo se examina la integración de esta técnica en los sistemas de monitorización geotécnica de laderas.
Los modelos físicos se emplean para elaborar análisis retrospectivos (back analysis) del movimiento de deslizamientos y predicciones cuantitativas. Este trabajo explora los beneficios de realizar análisis en 3 dimensiones, aprovechando la versatilidad de los programas de elementos finitos y la información obtenida de los sistemas de monitoreo para calibrar y validar los modelos. Se presenta una metodología avanzada que reproduce la cinemática de deslizamientos lentos de ladera activos en 3D.
En conjunto, esta tesis doctoral presenta una guía práctica integral para estudiar deslizamientos lentos de ladera a escala local, basada en la clasificación detallada del fenómeno, monitorización mediante técnicas A-DInSAR y modelos numéricos en 3D.Site scale slow moving landslides: characterization by monitoring and modelling

Premio de la Fundación J. García-Siñeriz a la Mejor Tesis en Geofísica

Año:2018
Director del trabajo:

Pablo J. González, codirigido con Jose Fernández (CSIC - Instituto de Geociencias) y Jose A. Fernández-Merodo (Instituto Geológico y Minero de España - IGME)  

Estudiante:

Guadalupe Marina Bru Cruz

Tipo:Tesis doctoral
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Fuente Nueva, Fasnia

Caracterización remota de variaciones de almacenamiento de agua subterránea usando Observaciones geofísicas y Modelado Poroelástico de Acuíferos bajo condiciones de Compactación y flujo Transitorio (COMPACT)

El proyecto “Caracterización de variaciones de almacenamiento usando Observaciones geofísicas y Modelado Poroelástico de Acuíferos bajo condiciones de Compactación y flujo Transitorio” (COMPACT -…

Investigador principal:

Dr. Pablo J. González

Estado:

En Ejecución

Selected Publications

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Temperature and Gaseous Emission

Spatial and Temporal Analysis of Temperature and Gaseous Emission Inside a Gallery in An Active Volcanic Island (Tenerife, Canary Islands)

In Tenerife there are a vast number of sub-horizontal blind water mines, called “galleries”. Seven air and soil temperatures and CO2 concentration profiles in air were carried out inside the Río de Guía gallery (hereinafter RdG). An anomalous stable maximum temperature point (hereinafter MTP) was found around 2000 m from the entrance. During the warm period, a clear CO2 stagnation was detected before MTP, showing concentrations up to 14,000 ppm. In order to study gas emission and its dynamics inside the gallery, four stations were deployed around MTP. All stations recorded air and soil temperatures, and CO2 and Rn concentration in air from November 2009 to January 2011. After analyzing this dataset, it was possible to characterize the influence of MTP. This thermal anomaly divided the gallery into two sections. In the cold period, the outer section located outwards from MTP became colder while the inner section warmed up owing to a less heat transfer into the deepest part of the gallery. There were several short periods when variations in barometric pressure created an advection movement that was able to temporally change the gas behavior inside the gallery. Two soil gas samples were taken around MTP and their δ13C (CO2) ratios suggested a magmatic origin. All data were combined to create a model for the gas and thermal dynamics inside the gallery. This model, together with identification of background levels in each parameter, allows to identify any anomalous signal that could be elated with changes in volcanic activity.

Torres-González, Pedro; Moure-García, David; Luengo-Oroz, Natividad; Villasante-Marcos, Víctor; Soler, Vicente; Iribarren, Ilaskiñe; Jiménez-Abizanda, Ana; García-Fraga, José

Pure and Applied Geophysics 176(8): 3467–3485 (2019)
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Eruption of Fogo Volcano

The 2014–2015 eruption of Fogo volcano: Geodetic modeling of Sentinel‐1 TOPS interferometry

After 20 years of quiescence, Fogo volcano erupted in November 2014. The eruption produced fast‐moving lava flows that traveled for several kilometers and destroyed two villages. This event represents the first episode of significant surface deformation imaged by the new European Space Agency's Sentinel‐1 satellite in its standard acquisition mode, Terrain Observation by Progressive Scans (TOPS), which differs from that of previous synthetic aperture radar (SAR) missions. We perform a Bayesian inversion of Sentinel‐1 TOPS SAR interferograms spanning the eruption and accurately account for variations in the TOPS line‐of‐sight vector when modeling displacements. Our results show that magma ascended beneath the Pico do Fogo cone and then moved laterally toward its southwestern flank, where the eruptive fissure opened. This study provides important insights into the inner workings of Fogo volcano and shows the potential of Sentinel‐1 TOPS interferometry for geophysical (e.g., volcano monitoring) applications.

González, Pablo J.; Bagnardi, Marco; Hooper, Andrew J.; Larsen, Yngvar; Marinkovic, Petar; Samsonov, Sergey V.; Wright, Tim J.

Geophysical Research Letter 42(21): 9239-9246 (2015)
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Magma storage and migration associated

Magma storage and migration associated with the 2011–2012 El Hierro eruption: Implications for crustal magmatic systems at oceanic island volcanoes

[1] Starting in July 2011, anomalous seismicity was observed at El Hierro Island, a young oceanic island volcano. On 12 October 2011, the process led to the beginning of a submarine NW‐SE fissural eruption at ~15 km from the initial earthquake loci, indicative of significant lateral magma migration. Here we conduct a multifrequency, multisensor interferometric analysis of spaceborne radar images acquired using three different satellite systems (RADARSAT‐2, ENVISAT, and COSMO‐SkyMed (Constellation of Small Satellites for Mediterranean Basin Observation)). The data fully captures both the pre‐eruptive and coeruptive phases. Elastic modeling of the ground deformation is employed to constrain the dynamics associated with the magmatic activity. This study represents the first geodetically constrained active magmatic plumbing system model for any of the Canary Islands volcanoes, and one of the few examples of submarine volcanic activity to date. Geodetic results reveal two spatially distinct shallow (crustal) magma reservoirs, a deeper central source (9.5 ± 4.0 km), and a shallower magma reservoir at the flank of the southern rift (4.5 ± 2.0 km). The deeper source was recharged, explaining the relatively long basaltic eruption, contributing to the observed island‐wide uplift processes, and validating proposed active magma underplating. The shallowest source may be an incipient reservoir that facilitates fractional crystallization as observed at other Canary Islands. Data from this eruption supports a relationship between the depth of the shallow crustal magmatic systems and the long‐term magma supply rate and oceanic lithospheric age. Such a relationship implies that a factor controlling the existence/depth of shallow (crustal) magmatic systems in oceanic island volcanoes is the lithosphere thermomechanical behavior.

González, Pablo J.; Samsonov, Sergey V.; Pepe, Susi; Tiampo, Kristy F.; Tizzani, Pietro; Casu, Francesco; Fernández, José; Camacho, Antonio G.; Sansosti, Eugenio

JGR Solid Earth 118(8): 4361-4377 (2013)
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Himalayan megathrust geometry

Himalayan megathrust geometry and relation to topography revealed by the Gorkha earthquake

The Himalayan mountain range has been the locus of some of the largest continental earthquakes, including the 2015 magnitude 7.8 Gorkha earthquake. Competing hypotheses suggest that Himalayan topography is sustained and plate convergence is accommodated either predominantly on the main plate boundary fault, or more broadly across multiple smaller thrust faults. Here we use geodetic measurements of surface displacement to show that the Gorkha earthquake ruptured the Main Himalayan Thrust fault. The earthquake generated about 1 m of uplift in the Kathmandu Basin, yet caused the high Himalaya farther north to subside by about 0.6 m. We use the geodetic data, combined with geologic, geomorphological and geophysical analyses, to constrain the geometry of the Main Himalayan Thrust in the Kathmandu area. Structural analyses together with interseismic and coseismic displacements are best explained by a steep, shallow thrust fault flattening at depth between 5 and 15 km and connecting to a mid-crustal, steeper thrust. We suggest that present-day convergence across the Himalaya is mostly accommodated by this fault—no significant motion on smaller thrust faults is required. Furthermore, given that the Gorkha earthquake caused the high Himalayan mountains to subside and that our fault geometry explains measured interseismic displacements, we propose that growth of Himalayan topography may largely occur during the ongoing post-seismic phase.

Elliott, J. R.; Jolivet, R.; González, P. J.; Avouac, J.-P.; Hollingsworth, J.; Searle, M. P.; Stevens, V. L. 

Nature Geoscience 9: 174–180 (2016)
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Surface uplift and time-dependent seismic hazard

Surface uplift and time-dependent seismic hazard due to fluid injection in eastern Texas

Observations that unequivocally link seismicity and wastewater injection are scarce. Here we show that wastewater injection in eastern Texas causes uplift, detectable in radar interferometric data up to >8 kilometers from the wells. Using measurements of uplift, reported injection data, and a poroelastic model, we computed the crustal strain and pore pressure. We infer that an increase of >1 megapascal in pore pressure in rocks with low compressibility triggers earthquakes, including the 4.8–moment magnitude event that occurred on 17 May 2012, the largest earthquake recorded in eastern Texas. Seismic activity increased even while injection rates declined, owing to diffusion of pore pressure from earlier periods with higher injection rates. Induced seismicity potential is suppressed where tight confining formations prevent pore pressure from propagating into crystalline basement rocks.

Shirzaei, M.; Ellsworth, W. L.; Tiampo, K. F.; Gonzalez, P. J.; Manga, M.

Science 353 (6306): 1416-1419 (2016)
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High‐resolution digital elevation model from tri‐stereo Pleiades‐1

High‐resolution digital elevation model from tri‐stereo Pleiades‐1 satellite imagery for lava flow volume estimates at Fogo Volcano

Resolving changes in topography through time using accurate high‐resolution digital elevation models (DEMs) is key to understanding active volcanic processes. For the first time in a volcanic environment, we utilize very high‐resolution tri‐stereo optical imagery acquired by the Pleiades‐1 satellite constellation and generate a 1 m resolution DEM of Fogo Volcano, Cape Verde—the most active volcano in the Eastern Atlantic region. Point cloud density is increased by a factor of 6.5 compared to conventional stereo imagery, and the number of 1 m2 pixels with no height measurements is reduced by 43%. We use the DEM to quantify topographic changes associated with the 2014–2015 eruption at Fogo. Height differences between the posteruptive Pleiades‐1 DEM and the preeruptive topography from TanDEM‐X give a lava flow volume of 45.83 ± 0.02 × 106 m3, emplaced over an area of 4.8 km2 at a mean rate of 6.8 m3 s−1.

Bagnardi, Marco; González, Pablo J.; Hooper, Andrew

Geophysical Research Letters 43(12): 6267-627 (2016)

Other research groups

Ciencias de la Vida y de la Tierra

Life and Earth Sciences

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Cabo Verde