SEGUIMIENTO ESPECIAL: Crisis sísmica-volcánica en El Hierro

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Re:SEGUIMIENTO ESPECIAL: Crisis sísmica-volcánica en El Hierro
« Respuesta #4224 en: Miércoles 01 Abril 2015 20:49:08 pm »
No recuerdo dónde leí ésta semana que desde hace unos días se registran seismos en el mar entre Tenerife y Gran Canaria y piensan que es otra volcán submarino que puede entrar en erupción.
UTIEL, ciudad vitivinícola, tierra de heladas y granizadas.
Iglesia Arciprestal del siglo XVI de estilo gótico, centenaria Plaza de Toros, Bodegas subterráneas medievales en el centro histórico, Santuario del Remedio del siglo XVI, Ayuntamiento neoclásico, iglesias de La Merced y San Francisco, Museo del vino.
Utiel es uno de los primeros municipios españoles que recibió el título de Ciudad, honor que ostenta desde 1645.

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Re:SEGUIMIENTO ESPECIAL: Crisis sísmica-volcánica en El Hierro
« Respuesta #4225 en: Miércoles 01 Abril 2015 23:42:28 pm »
No recuerdo dónde leí ésta semana que desde hace unos días se registran seismos en el mar entre Tenerife y Gran Canaria y piensan que es otra volcán submarino que puede entrar en erupción.
El volcán de Enmedio, llamado así por estar precisamente en medio de las dos islas mayores. Parece que entró en erupción en 1989.
Tienes problema. No solución. No problema. (Sensei Miyagi)

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Re:SEGUIMIENTO ESPECIAL: Crisis sísmica-volcánica en El Hierro
« Respuesta #4226 en: Jueves 02 Abril 2015 12:20:47 pm »
No recuerdo dónde leí ésta semana que desde hace unos días se registran seismos en el mar entre Tenerife y Gran Canaria y piensan que es otra volcán submarino que puede entrar en erupción.
El volcán de Enmedio, llamado así por estar precisamente en medio de las dos islas mayores. Parece que entró en erupción en 1989.

Pero no esta en las efemérides, no?? o no recuerdo haberlo visto...y hay alguna información sobre este volcán??
Informando desde Metro Antonio Machado 600/650 msnm
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Re:SEGUIMIENTO ESPECIAL: Crisis sísmica-volcánica en El Hierro
« Respuesta #4227 en: Jueves 02 Abril 2015 14:47:43 pm »
No recuerdo dónde leí ésta semana que desde hace unos días se registran seismos en el mar entre Tenerife y Gran Canaria y piensan que es otra volcán submarino que puede entrar en erupción.
El volcán de Enmedio, llamado así por estar precisamente en medio de las dos islas mayores. Parece que entró en erupción en 1989.

Pero no esta en las efemérides, no?? o no recuerdo haberlo visto...y hay alguna información sobre este volcán??
Jolín, Meteoalcobendas. Basta picar el Google y escribir "Volcan de Enmedio". Hay bastantes noticias y enlaces sobre el evento.. [emojifacepal01]
Sanlúcar de Barrameda (Cádiz)...En la desembocadura, a orillas del Guadalquivir y Bético, para lo bueno y lo malo

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Re:SEGUIMIENTO ESPECIAL: Crisis sísmica-volcánica en El Hierro
« Respuesta #4228 en: Jueves 02 Abril 2015 18:23:59 pm »
No recuerdo dónde leí ésta semana que desde hace unos días se registran seismos en el mar entre Tenerife y Gran Canaria y piensan que es otra volcán submarino que puede entrar en erupción.
El volcán de Enmedio, llamado así por estar precisamente en medio de las dos islas mayores. Parece que entró en erupción en 1989.

Pero no esta en las efemérides, no?? o no recuerdo haberlo visto...y hay alguna información sobre este volcán??
Jolín, Meteoalcobendas. Basta picar el Google y escribir "Volcan de Enmedio". Hay bastantes noticias y enlaces sobre el evento.. [emojifacepal01]

Vale vale, perdón, no volverá a ocurrir, con ese nombre tan curioso no se me habia ocurrido  buscarlo.
Informando desde Metro Antonio Machado 600/650 msnm
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Re:SEGUIMIENTO ESPECIAL: Crisis sísmica-volcánica en El Hierro
« Respuesta #4229 en: Jueves 16 Abril 2015 19:44:36 pm »
Buenas tardes.

Nadie habla de una posible reactivacion de El Hierro debido a la cantidad de seísmos que hay en la isla.
El Fargue (Granada).  Entre la impresionante mole de Sierra Nevada y la suavidad de la Vega de Granada 1000 msnm.

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Re:SEGUIMIENTO ESPECIAL: Crisis sísmica-volcánica en El Hierro
« Respuesta #4230 en: Miércoles 13 Mayo 2015 03:59:29 am »
Enga... enga...
menos excusas y a pagar las birras...  :sonrisa:

Where is the tremor?  :sonrisa:

http://www.ign.es/ign/head/volcaSenalesAnterioresDia.do?nombreFichero=CHIE_2012-03-12&ver=s&estacion=CHIE&Anio=2012&Mes=03&Dia=12&tipo=2






Ahora sin cachondeo...  :sonrisa:

reiki...
Lo que preguntaste el otro día del tremor o ruído de fondo en otras islas...
Siempre he tenido la sensación de que se pudiese detectar de algún modo el movimiento en las profundidades...
pero si tenemos que hacer caso a los expertos, ya sabes lo que opina Itahiza del IGN. Que esos ruídos de fondo son debidos a fenómenos meteorológicos y dependiendo también del estado del mar...

En cuanto a las 3 patas de la mesa:
Sismicidead, gases, deformación...

La sismicidad si la comparas incluso con el 1er día de las crisis sísmica, 19 de julio, es baja. O el 19 de julio entonces era el fin del mundo. La sismicidad que se está produciendo ahora es ridícula si la comparamos con los primeros tiempos en que se inicio la crissi sísmica y paupérrima si la comparamos con la actividad que hubo en noviembre.
Deformación; no hay inflación e incluso la deformación podría quedar estable.
Gases; tampoco son demasíado concluyentes...

Esos 3 parámetros anteriores no pueden ser considerados individualmente... Para que todos eso signifique algo deben de ir en conjuntos y con varios activados fuertemente.

Acordémonos de cuando la crisis en Tenerife, que se lió parda con las mediciones de gases y un sismo...

Sensación de que no estamos hablando de una reactivación inminente...

Por otro lado, siempre queda la sensación de que vaya a saber porqué pues que las máquinas no estén engañando y que ahí siguiese saliendo magma...

Pero vamos, la sensación de que este primer capítulo ha terminado es muy fuerte...

Y cuando hablo de 1er capítulo, no me estoy refiriendo a que haya de haber más capítulos...
Para eso tendríamos que tener unos indicios más fuertes y conjuntos a nivel de sismicidad, a nivel de gases y a nivel de deformación...
No habrá una erupción en otro sitio a menos que se dé deformación acelerada.



oye puntal,   decías que se había acabado?     

http://www.vulcanoelhierro.es/vulcana0515-cazadores-de-plumas

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Re:SEGUIMIENTO ESPECIAL: Crisis sísmica-volcánica en El Hierro
« Respuesta #4231 en: Miércoles 20 Abril 2016 18:49:43 pm »
Buenas tardes, El Hierro no esta muerto ni mucho menos.
20/04/2016   13:34:25   27.9874   -17.9250   26   III-IV   4.2   4   N VALVERDE.IHI
El Fargue (Granada).  Entre la impresionante mole de Sierra Nevada y la suavidad de la Vega de Granada 1000 msnm.

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Re:SEGUIMIENTO ESPECIAL: Crisis sísmica-volcánica en El Hierro
« Respuesta #4232 en: Jueves 23 Febrero 2017 13:03:33 pm »
La revista científica "Journal of Volcanology and Geothermal Research" publicará en su próxima edición impresa la última de las investigaciones a las que ha dado pie una de las primeras erupciones monitorizadas en directo a lo largo de todo su desarrollo, que en este caso pone el foco en lo que ocurrió después.

Se calcula que el magma que se acumuló bajo El Hierro en los meses previos a la erupción desencadenó más de 10.000 seísmos, la mayoría de ellos de baja intensidad, y elevó la isla unos cinco centímetros, hasta que toda esa presión encontró una vía de escape bajo el mar de Las Calmas por la que brotaron unos 0,329 kilómetros cúbicos de materiales volcánicos (el volumen estimado de su cono).

Cinco investigadores del Instituto Geográfico Nacional (IGN), el Instituto de Ciencias de la Tierra de la Universidad de Islandia y el Centro para la Observación y Modelado de Terremotos de la Universidad de Leeds (Reino Unido) dan a conocer ahora un estudio sobre las seis reactivaciones volcánicas que se produjeron en la isla ya acabada la erupción, entre junio de 2012 y marzo de 2014.

La primera firmante del trabajo, María Ángeles Benito-Saz, del IGN, ha explicado a Efe que el caso de El Hierro "parece muy excepcional, si no único", porque lo habitual en los volcanes es que la elevación del terreno por la presión del magma bajo el subsuelo ocurra antes de la erupción, para luego reducirse o desaparecer cuando la lava emerge y comienza la fase de "descanso".

Con datos proporcionados por las estaciones sísmicas y de GPS repartidas a lo largo de la isla y los satélites de la Agencia Espacial Europea (ESA), este grupo de científicos ha puesto cifras al magma que quedó bloqueado bajo la isla en esos meses sin llegar a provocar otra erupción: entre 0,32 y 0,38 km3 (el equivalente a todo el agua que puede embalsar la presa de Tous, en Valencia)

En esos meses, el magma fue emergiendo del manto hacia el subsuelo de El Hierro en un intrusiones muy rápidas, seguidas y con mucha energía acumulada, que, por algún motivo, se detuvieron a profundidades de entre 14 y 16 kilómetros. Como resultado, la isla se hinchó literalmente de 20 a 27 centímetros (según zonas) por la presión que ejercía todo ese material fundido y tembló 5.400 veces.

Benito-Saz subraya así la energía que tuvieron esas intrusiones de magma: "Antes de la erupción, se midieron cinco centímetros de deformación, pero en tres meses. En cambio, en esos seis períodos, deformaciones de cinco centímetros se producían en solo dos días".

Sin embargo, no hubo una segunda erupción, ¿por qué? Los científicos que han estudiado el volcán Tagoro han demostrado que el magma se desplazó en horizontal bajo la isla varios kilómetros en los meses previos a la erupción, hasta que uno de los seísmos más potentes que se vivieron aquellos días abrió algún tipo de grieta.



http://www.canarias7.es/articulo.cfm?id=454274

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Re:SEGUIMIENTO ESPECIAL: Crisis sísmica-volcánica en El Hierro
« Respuesta #4233 en: Jueves 06 Diciembre 2018 04:11:55 am »
COMPORTAMIENTO CÍCLICO ASOCIADO CON EL PROCESO DE DESGASIFICACIÓN EN EL VOLCÁN SUBMARINO POCO PROFUNDO TAGORO, EL HIERRO, ISLAS CANARIAS.- Interesante publicación hoy en la revista Geoscience, Volumen 8, Número 12 del IEO o Instituto Español de Oceanografía. Les dejo la traducción del resumen original, sin duda una interesante apuesta por estudiar y comprender mejor nuestros volcanes y su actividad. (Enrique)

"El Tagoro, el volcán submarino poco profundo descubierto más recientemente en el archipiélago de las Islas Canarias, España, ha sido estudiado desde el inicio de su fase eruptiva en octubre de 2011 hasta noviembre de 2018. En marzo de 2012, se convirtió en un sistema hidrotermal activo que implica una emisión de calor y Gases que producen importantes anomalías físico-químicas en las aguas circundantes cercanas al fondo marino.

Analizando las transformadas de Fourier rápida (FFT) y técnicas de análisis de la frecuencia en el dominio del tiempo de onda aplicadas a series de tiempo filtradas de datos de temperatura, salinidad, presión, pH y potencial de reducción de la oxidación (ORP) de un dispositivo de conductividad-temperatura-profundidad (CTD) montado en un amarre y desplegado en la parte más profunda del cráter principal a una profundidad de 127 m, se han tomado datos e utilizado para comprender mejor los procesos dinámicos de las emisiones durante la fase de desgasificación del volcán Tagoro.

Nuestros resultados resaltan que el sistema hidrotermal exhibió un comportamiento estacionario de desgasificación cíclica, con un fuerte pico de un período de 140 minutos centrado en un intervalo significativo de 130-170 minutos con una confianza del 99,9%. Por otra parte, importantes anomalías físico-químicas aún están presentes en el interior del cráter principal, como:

(i) aumento térmico de +2.55 ° C,
(ii) disminución de la salinidad de −1.02,
(iii) disminución de la densidad de −1.43 ( kg ∙ m −3 ), y
 (iv) disminución del pH de −1.25 unidades.

Esto confirma que, cinco años después de su origen, el volcán submarino Tagoro aún está activamente en una fase de desgasificación.

RESUMEN:

https://www.mdpi.com/2076-3263/8/12/457?fbclid=IwAR3eABr0qN9NfC3VjLAktLx4XWYfL1Z2fDHGBBLb2cAfxsjg2xYpLWCeCuk


TEXTO COMPLETO:

https://www.mdpi.com/2076-3263/8/12/457/htm


PD: Pueden usar el traductor de Google para traducir el artículo al español.









Volume 8, Issue 12

Open Access
Geosciences 2018, 8(12), 457; doi:10.3390/geosciences8120457
Article
Cyclic Behavior Associated with the Degassing Process at the Shallow Submarine Volcano Tagoro, Canary Islands, Spain
Eugenio Fraile-Nuez 1,* OrcID, J. Magdalena Santana-Casiano 2, Melchor González-Dávila 2, Juan T. Vázquez 3OrcID, Luis Miguel Fernández-Salas 4OrcID, Olga Sánchez-Guillamón 3OrcID, Desirée Palomino 3OrcID and Carmen Presas-Navarro 1
1
Instituto Español de Oceanografía, Centro Oceanográfico de Canarias, Santa Cruz de Tenerife 38180, Spain
2
Instituto de Oceanografía y Cambio Global, Universidad de Las Palmas de Gran Canaria, 35017 Las Palmas de Gran Canaria, Spain
3
Instituto Español de Oceanografía, Centro Oceanográfico de Málaga, 29640 Málaga, Spain
4
Instituto Español de Oceanografía, Centro Oceanográfico de Cádiz, 11006 Cádiz, Spain
*
Author to whom correspondence should be addressed.
Received: 17 October 2018 / Accepted: 29 November 2018 / Published: 4 December 2018
Abstract: Tagoro, the most recently discovered shallow submarine volcano on the Canary Islands archipelago, Spain, has been studied from the beginning of its eruptive phase in October 2011 until November 2018. In March 2012, it became an active hydrothermal system involving a release of heat and gases that produce significant physical–chemical anomalies in the surrounding waters close to the seabed. Fast Fourier transform (FFT) and wavelet time-domain-frequency analysis techniques applied to filtered time series of temperature, salinity, pressure, pH, and oxidation-reduction potential (ORP) data from a conductivity-temperature-depth (CTD) device mounted on a mooring and deployed at the deepest part of the main crater at a depth of 127 m, have been used to better understand the dynamic processes of the emissions during Tagoro’s degasification phase. Our results highlight that the hydrothermal system exhibited a stationary cyclic degassing behavior with a strong peak of a 140-min period centered on a significant interval of 130–170 min at 99.9% confidence. Moreover, important physical–chemical anomalies are still present in the interior of the main crater, such as: (i) thermal increase of +2.55 °C, (ii) salinity decrease of −1.02, (iii) density decrease of −1.43 (kg∙m−3), and (iv) pH decrease of −1.25 units. This confirms that, five years after its origin, the submarine volcano Tagoro is still actively in a degassing phase.
Keywords: hydrothermal vents; cyclic behavior; submarine volcano; Tagoro; El Hierro
1. Introduction
Shallow hydrothermal vents are located in different tectonic settings, in particular related to recent subaerial and submarine volcanic activity, along arcs and mid ocean ridges, and in areas presenting intraplate oceanic volcanism [1,2,3,4,5]. Hydrothermal emissions are associated with the release of heat and gases, and acidic and reduced metal-rich fluids [6,7,8]. The chemical composition of hydrothermal fluids changes as the deep and shallow systems are affected by variations in permeability, induced by seismic events and related to fluid overpressures. These emissions significantly affect the properties of seawater and marine sediments [9,10], changing geochemical processes and mineralization patterns [11]. Hydrothermal vents have been studied in terms of fluid geochemistry characterization, physical-chemical processes [3,12,13], and biological communities [14]. Fewer studies have been carried out on the water dynamics in the near field of hydrothermal vents [13,15,16]. Water dynamics can change with the intensity of the flux of fluids and with seismic activity in the area [17]. It has been observed that the effect of pressure fluctuation with tide can generate intermittent behavior in the bubble jet of shallow hydrothermal vents [15]. Emissions of gases, fluids, and heated water from hydrothermal vents generate upward convective plumes in the area that can be advected and diluted, depending on the dynamics and energy of the system [18]. At shallow depths, vent plumes are usually small [19]. Moreover, in these areas, where hydrostatic pressure is not the major force controlling gas dilution and water boiling, vents are of the hydrothermal type, with high flow rates of free gas, principally CO2, and many diffusive and sparse columns of gas bubbles are frequent [15,16,20,21].
Volcanic eruptions often show cyclic trends in their rate of occurrence over a range of timescales [22,23,24,25,26]. Seismic and acoustic volcano monitoring signals also show systematic cyclicity [25,27,28]. However, the processes underlying such cyclic activity remain uncertain. Volcanic degassing provides crucial information on the dynamics of magmatic systems and eruptions [24,29,30,31]. Although several studies reveal the existence of cyclic behaviors in the release of heat and gases from different sub-aerial volcanoes [24,25,26,32,33,34] and underwater volcanic systems [18,23,35], oceanic volcanoes have received less attention. Hydrothermal vents occur globally in deep and shallow oceans, although records of shallow vents are less numerous than for those found in the deep sea [36,37,38,39,40,41,42,43].
In October 2011, at La Restinga–El Mar de Las Calmas Marine Reserve, a submarine volcano eruption took place 1.8 km south of the coast of El Hierro (27° 37.116′ N, 017° 59.466′ W, Figure 1). During the next six months, extreme physical–chemical perturbations caused by this event, comprising thermal changes, water acidification, deoxygenation, and metal enrichment, resulted in significant alterations of the marine ecosystem [44,45]. After March 2012, once the eruptive phase was over, the submarine volcano Tagoro entered an active hydrothermal phase that involved a release of heat, gases, and metals [21].
The Tagoro volcano has a basanitic nature and is monogenetic, generated entirely during the underwater eruption that took place between October 10, 2011 and March 5, 2012 (Figure 1c–d). The eruption took place at a 355 m depth on the southern submarine promontory off El Hierro Island, on the western wall of a submarine gully with a NNE–SSW direction. From this moment, the volcano grew through several pulses of activity, forming a main cone located NW of the starting point, with a summit at a 88 m depth. Subsequently, volcanic vents were successively formed to the SSE of the main cone, generating alienated secondary cones and the final geometry of the volcano. The eruption generated three main volcanic domains, situated progressively deeper to the SW: the Tagoro volcano s.s., a lava-debris flow apron, and a lobe like body. The first sector, where this work has been carried out, corresponds to a slightly elongated volcanic cone that rises from a 400 to 88 m depth. The edifice has slopes between 20 and 45°, which are steepest close to the different volcanic vents and smoother in lower flank areas. It has an irregular base (1–1.3 km in diameter) and an elongated summit in a NNW–SSE direction.
This volcanic edifice is characterized by several volcanic vents which produced at least 14 volcanic cones located in the axis of the edifice. The diameter of the main cone is 400 m, and those of the 13 secondary cones vary between 75 and 140 m, decreasing in size towards the SSE. Minor depressions are also differentiated close to the secondary cones, with diameters ranging from 15 to 35 m. The most pronounced has been located on top of an ENE–WSW arc-shape crest at approximately a 116 m depth, where the second-highest volcanic cone is also located. This crest corresponds to an internal discontinuity between the main edifice and the SSE prolongation of secondary cones. In this context, this main crater vent (Figure 1d) has a circular shape, with a length of 35 m and depth of 126–130 m. It has an asymmetric geometry as a consequence of its development on an inclined surface. The north-western rim walls correspond to the volcano’s main flank, with slopes ranging from 20 to 35° and height relative to the depression floor of up to 13 m, while the south-eastern rim walls are characterized by a minor crest of a 3 m height and slopes varying from 12 to 18°. This depression corresponds to the location of the main hydrothermal vent at present. Although the whole crater worked as a diffuse degassing system, the degassing process was even more visible at specific areas covered by chimney fields (5–10 cm high) and cracks (Figure 2). This crater vent and its out-gassing source were first monitored in the column water with CTD exploration, tow-yos transects, and ROV images by this research team [21].
As one of the newest and shallowest active submarine volcanoes in Europe, the Tagoro volcano is an excellent natural laboratory to study the dynamics associated with the degasification process. Here, we report significant physical–chemical anomalies and a cyclic degassing dynamic at Tagoro, five years after the beginning of the degasification phase, with a complete time series of temperature, salinity, pressure, pH, and oxidation-reduction potential (ORP) data from an RBR CTD device and a Seabird 27 pH-ORP sensor mounted on a mooring in the deepest point of the main crater at a 127 m depth (27° 37.178′ N, 017° 59.574′ W, Figure 1d–e).
2. Materials and Methods
In October 2016, five years after the completion of the magmatic activity, a multidisciplinary oceanographic cruise in the context of the VULCANO-II project was carried out in order to characterize the physical–chemical anomalies of the underwater volcano in a degassing stage (Figure 1a–b). During this cruise, on board R/V Ángeles Alvariño of the Spanish Institute of Oceanography, a mooring equipped with an RBR CTD device (RBR, Ottawa, ON, Canada) and a Seabird 27 pH-ORP sensor (Sea-Bird Electronics, Bellevue, WA, USA) was deployed at the deepest point of the more active crater of the Tagoro submarine volcano at a 127 m depth (Figure 1e). The accuracy of the temperature, conductivity, pH, and ORP sensors was 0.002 °C, 0.003 S/m, 0.02 units, and 1.0 mV, respectively. The sensors were calibrated at the point of manufacture before and after deployment, and for the time of the observation, no drift was observed.
The mooring was deployed on 10 October 2016. The sensors were programmed to start sampling at the same moment, but due to an internal problem with the hard drive of the datalogger, the CTD was operative only during the first eight days, from 30 October 2016 to 6 November 2016, with a sampling interval of ten seconds, while the pH-ORP sensor was operative for 41 days, from 13 November 2016 to 24 December 2016, with a sampling interval of three minutes. For this last data series, the first 15 days, from 30 October 2016 to 12 November 2016, were missed. The mooring was recovered during the VULCANA-0417 cruise in April 2017, in the context of the VULCANA project of the Spanish Institute of Oceanography using a Super Mohawk II ROV Liropus 2000 (Sub-Atlantic, Aberdeen, UK). The different time series were resampled every five minutes and a high-pass filter with a cut-off of five hours was applied in order to eliminate low frequencies, such as diurnal and semidiurnal tides and inertial signatures.
In order to evaluate and quantify the anomalies and the variability of the physical–chemical properties in the area exclusively due to the volcanic activity, as a reference, a dataset of the mean profiles of every variable was obtained using four full hydrographical CTD stations placed at the east part of the island (Figure 1b, stations 1, 2, 202, and 3). These stations were not influenced by the perturbations of the submarine volcano at this time. The obtained reference data are, hereafter, denoted ref-mean. CTD profiles were carried out using a Seabird 911+ with a double sensor of temperature and conductivity, together with a 24 10-L bottle carousel for water samples. The accuracy of the temperature and conductivity sensors was 0.001 °C and 0.0003 S/m, respectively.
A bathymetric digital elevation model of the seafloor was obtained with data from a Kongsberg Simrad EM-710 multibeam echosounder (Kongsberg Maritime AS, Kongsberg, Norway) (70 to 100 kHz), with a spatial grid resolution of 1 m (Figure 1c–d), which allowed us to detect and localize the main crater (35 m diameter) of the submarine volcano Tagoro in order to deploy the mooring at the deepest point of the crater (127 m depth). This was possible due to the accuracy of the bathymetry data and the dynamic position (DP) system of the oceanographic vessel Ángeles Alvariño.
High definition images from an ROV of the Spanish Institute of Oceanography have been used to describe the geomorphology of the main crater and determinate the presence of the chimney and diffuse vent area. Images were collected during Vulcana-II-0417 and Vulcana-II-1118 cruises, in April 2017 and November 2018, respectively.
The nature of the fluctuations of different properties was investigated using two different time series analysis techniques. The first was a modification of a Fast Fourier Transform (FFT) [46,47], which provides information on the signal power content at any frequency, but loses the frequency location in the time domain. This widely used technique is designed for stationary signals; however, our time series could have contained non-stationary or transitory characteristics, such as drifts, trends, abrupt changes, onsets, and even ends of events. These characteristics are often the most important part of the signal, and Fourier analysis is not suited for their detection [24]. For this reason, we applied the wavelet transform (WT), which, in contrast to the FFT, consists of a linear superposition of independent and non-evolving periods that preserves frequency location in the time domain [48,49]. In that way, wavelet power spectra can provide better time and frequency localization than Fourier transform-based methods, due to being more suitable for analyzing cyclicity in non-stationary time series [50]. We used a Morlet wavelet and the Matlab code toolbox of Grinsted [51].
3. Results
Five years after the end of the eruptive phase of the submarine volcano Tagoro, south of the island of El Hierro, important physical–chemical anomalies are still present in the area. Non-affected vertical profiles of potential temperature, θ (°C); salinity, S; potential density, σθ (kg∙m−3); and pH (NBS scale) with depth (m) for the whole water column as a mean of the stations (1, 2, 202, and 3) with their standard deviation are shown in Figure 3. Affected data recorded by the sensors located at the mooring at the interior of the crater are shown in red. Our results show, in reference to the ref-mean values, that the hydrothermal system exhibited maximum physical–chemical anomalies, with an increase in potential temperature of +2.55 °C, a decrease in salinity of −1.02, a decrease in density of −1.43 kg∙m−3, and a decrease in pH of −1.25 units. Table 1 shows the minimum, maximum, and mean values with standard deviation, ref-mean values of non-affected water at the depth of the main crater (127 m), and the maximum anomalies found in the area.
Low salinity in the water column above the main crater is directly associated with substantial positive temperature anomalies. Such low-salinity fluids are likely to form in a relatively shallow (low pressure) phase-separating hydrothermal system [52,53] that can separate seawater into two conjugate fluids: a condensed-vapor low-salinity fluid and a residual brine. Although a less-dense low-salinity fluid was present in greater proportion (Sal < Salref), the higher density fluid (Sal > Salref) was also sampled. Thus, variation in the thermohaline properties may produce a hydrothermal positive buoyancy that causes plumes to rise, with the rise-height limited by the steep density gradients in the water column at the depth of approximately 60 m.
In order to isolate the release of heat and gases from the main crater of the shallow submarine volcano Tagoro, a complete time series of the anomalies recorded by the combined CTD-pH-ORP sensors installed at the mooring at a depth of 127 m has been studied. Anomalies of potential temperature, salinity, and potential density, respectively, together with a five-minute moving average, are represented in Figure 4a–c. Sea surface elevation derived from the analysis of the pressure data sensor of the CTD device is presented in Figure 4d. Similarly, Figure 4e–g show the pH anomaly, ORP time series, and the first time derivative of the ORP data, respectively, with a five-minute moving average for pH and ∂(ORP)/∂t. Finally, Figure 4h shows the theoretical tide for this period of time [54] (pressure data not available).
Two different time-domain-frequency analysis techniques have been applied to the filtered time series for potential temperature, salinity, and pressure, respectively (Figure 5a1–a3): the power spectra and statistical significance were computed by a modification of fast Fourier transform [46] (Figure 5b1–b3) and wavelet analysis (Figure 5c1–c3). The results of the time-frequency analysis show a strong peak of over 99.9% significance present in the decomposition of the potential temperature, salinity, and pressure time series anomalies, with a period centered at approximately 140 min and included in a significant interval of 130–170 min. This significant peak explains 41% of the total variance of the signal. The results obtained by power spectral analysis are consistent with those obtained by wavelet analysis (Figure 5c1–c3), and show significant spectral power (highlighted by the black line at 95% confidence level), mainly between 80 and 160 min with stationary features. Other signals, centered around 40 min, appear not to be steady, but localized in time.
Figure 6 shows the application of FFT and wavelet time-domain-frequency analysis techniques applied to pH and ∂(ORP)/∂t time series, with the longest obtained from the interior of the main crater by the sensors located at the mooring (Figure 6a1–a2). The results of the time-frequency analysis show a significant interval of 100–165 min, with the peak centered at 145 min (Figure 6b1–b2). Wavelet analyses show identical responses for both variables, with significant spectral power mainly between 80 and 160 min with stationary features, and other signals centered around 40 min and localized in specific time intervals (Figure 6c1–c2). Thus, the same significant peak has been obtained during the application of the time-frequency analysis to the five independent variables studied in this work (temperature, salinity, pressure, pH, and ORP).
4. Discussion
Through this study, different time series of temperature, salinity, pressure, pH, and ORP from the deepest part (127 m) of the main crater of the submarine volcano Tagoro have been studied in order to (a) quantify the physical–chemical anomalies of the degassing process, and (b) apply different time-frequency analysis techniques to determinate significant cyclic behavior in the release of hydrothermal fluids.
Our results show that, five years after the beginning of the degassing process, thermal anomalies up to +2.55 °C, salinity anomalies up to −1.02, density anomalies up to −1.43 (kg∙m−3), and pH anomalies up to −1.25 units were still observed in the interior of the main crater. Our reference profiles (Figure 2) show that water masses with salinity anomalies of −1.02 could be found in the water column at a depth of 550 m or deeper. In the case of pH (Figure 3d), water masses with pH anomalies of −1.25 are too acidic to be found in the first 2000 m of the water column in the Canary Islands region [45]. According to these assumptions, these physical–chemical anomalies should be due to the release of hydrothermal fluids from the vents around the volcanic edifice of Tagoro and not to upwelling from deeper water masses around the area.
Previous results obtained in the same area, but in the water column around the main crater with the use of a rosette, show an increase in temperature of +3.0 °C, a decrease in salinity of −0.3, and a decrease in pH by −0.25–0.30 units [8,21]. These results are in agreement with the results obtained over other active hydrothermal vents. Temperature and salinity anomalies of +1.0 °C and −0.21, respectively, were obtained in the interior of a crater of the Vailulu’u seamount at a 950 m depth in Samoa [53], and temperature and salinity anomalies up to +3.0 °C and −0.15, respectively, were found in the interior of the Kolumbo submarine volcano at a 500 m depth in Santorini [55]. Moreover, our pH values seem to be similar to those obtained over the Ahyi (−0.5), NW Rota (−0.73), West Mata (−1.51), Nikko (−0.16), Daikoku (−0.05), and Kasuga-2 (−0.313) hydrothermal plumes [56,57,58,59].
Cyclic behavior has been recognized at a number of open-vent volcanoes around the world. Pulsatory patterns in both degassing [25,32,33,60] and in the behavior of active lava lakes [61,62] have been observed. High-time resolution thermal image datasets recorded at Etna, Stromboli, and Kilauea volcanoes retrieved cycles that vary within similar time windows, grouped into three main classes: (i) cycles with periods <15 s related to Sharp pulses in the thermal signal (gas puff/discrete Strombolian explosions; [63]); (ii) periods between ~20–50 s and 1–10 min associated with the bursting of hot, over-pressured gas bubbles/trains of bubbles [64] at the magma–air interface; and (iii) long cycles with periods of 12–90 min reflecting dynamics occurring within the shallow magma supply system [24]. For decades, Stromboli has been an ideal laboratory for studying the different modes and rates of gas release from active volcanoes. In fact, its active degassing (explosions and puffing) plays a key role in modulating a longer term cyclic (periods 300–700 s) SO2 degassing behavior, which represents a key target to be explored in future research [60]. Cyclic volcanic degassing behaviors have also been characterized in the release of gas flux for Mount Etna at two period bands (40–250 s and 500–1200 s), which suggest a bursting of rising gas bubble trains at the magma–air interface [25]. Cyclic degassing of the Erebus volcano in Antarctica has also been registered in the total gas column amount, a likely proxy for gas flux, with periods of 10, 35, and 70 min, which can be explained in terms of chemical equilibria and pressure-dependent solubility [26]. Cyclic behavior with spattering episodes of 40–100 m in a lava pool was first documented in Kilauea volcano [62].
Subaerial and submarine eruptions are often thought of in very different terms due to the sharp contrast between quench conditions in air and water. The same surprising similarities were found at NW Rota-1 in the spine-growth velocities, which control the syn-ascent crystallization and degassing [65]. For submarine eruptions driven by magmatic degassing, temporally cyclic behavior appears to be a fundamental characteristic at a wide range of extrusion rates [65]. In submarine ambient conditions, the tidal cycle seems to be of greater importance in the driving forces of these variations [18,23,66]. Other periods exist that may be generated by the turbulent mixing occurring in this environment, by changes due to the directions of local currents, and/or by variations in the hydrothermal fluid discharge [3,66,67]. In our case, variations in the in situ pressure sensor data show that the total signal of the tide is explained by the M2 type at 97.3% of the total variance with a mean amplitude of 0.92 ± 0.02 m, a period of 12 h, and negligible velocity relative to the predominant local mean current [54]. Although our data, before filtering the low frequencies, presents a tidal relationship, the behavior shown in Figure 5 and Figure 6 presented a period too short to depend on the existing M2 type tide of the area, as was also reported in other similar studies [18,23,66]. Moreover, the velocity observation with a vessel-mounted acoustic doppler current profiler (VMADCP) indicates that the local current intensities in the area were very low (1.5 ± 1.0 cm/s) and stable, with a main southward direction [21].
Although cyclicity studies at submarine hydrothermal vents are less frequent that those at subaerial vents, hydrophone records at NW Rota-1 show that bursts of Strombolian explosive degassing at the volcano summit (520 m deep) occurred at 1–2 min intervals during the entire 12-month time series, and commonly exhibited cyclic step-function changes between high and low intensity [35]. Other studies have interrelated the cyclicity of eruptive activity with mass wasting at submarine arc volcanoes [65]. Moreover, time-series of temperature and velocities over a diffuse flow at Juan de Fuca Ridge show evidence of cyclic modulation of 12.4 h, 16–17 h, and four to five day periods, suggesting that temperature variability correlates with the variability of the current speed and direction, not with the ocean’s tidal pressure [18]. Thus, the modulation of temperature by tides is only indirect, through the modulation of horizontal bottom currents. In our case, and in order to avoid the effect of the tide, frequencies higher than 6 h were removed from our data. Our filtered time-series reflect cyclic behaviors of frequencies higher than the semi-diurnal tide period.
Tagoro is the first submarine volcano in the Canary Islands region that presents a clear cyclic behavior in the release of heat and gases during its degasification phase. This cyclic behavior (130–170 min) is in the same order of the longest cycles found for Etna, Stromboli, Kilauea, and Erebus volcanoes [24,26], although more information is needed to establish possible cyclic patterns in higher frequencies from seconds to minutes.
5. Conclusions
The variability and duration of cyclic events provide new and relevant information for tracking and constraining the associated physical–chemical processes and their effects on the marine ecosystems linked to shallow submarine degassing areas. In addition, such information can also provide a warning of future eruptions in the area, since it is hypothesized that in complex, non-linear natural systems, drastic changes or tipping points are often preceded by a period of enhanced variability [68,69].
Our results highlight that the submarine volcano Tagoro is still active in its degasification phase, five years after its origin, with significant physical–chemical anomalies of up to +2.55 °C in temperature, −1.02 in salinity, and −1.25 units in pH. Moreover, our results, obtained by the application of two different time-domain-frequency analysis techniques to the filtered time series of potential temperature, salinity, pressure, pH, and ORP, show a strong peak of over 99.9% significance centered at approximately 140 min and immersed in a significant interval of 130–170 min, alternated between periods of high and low activity. For all of this, Tagoro has been the first submarine volcano at the Canary archipelago presenting a clear cyclic behavior in its degassing process at frequencies higher than the semidiurnal M2 tide. Although this cyclic behavior may be related to variations in hydrothermal fluid discharge that reflect dynamics occurring within the magmatic system [24] or cyclic dynamic processes occurring in the conduit system [70], we encourage the further use of time-frequency analysis using longer and higher temporal resolution observations recorded by a permanent mooring in the area, and their comparison and integration with geophysical parameters. Variability studies of these cyclic behaviors represent a key target to be studied in order to understand the complex degassing dynamic of these hydrothermal systems.
Author Contributions
Study design: E.F.N., J.M.S.C., and M.G.D. Data processing and graphical representations: E.F.N. and O.S.G. High resolution bathymetry and deployment: E.F.N., J.TV., L.M.F.S., D.P., O.S.G., J.M.S.C., and M.G.D. Writing of the manuscript, conclusion, and discussion of the results: E.F.N., J.M.S.C., M.G.D., J.T.V., L.M.F.S., D.P., O.S.G., and C.P.N.
Funding
This research was funded by Ministerio de Economía y Competitividad del Gobierno de España (MINECO) and FEDER through VULCANO (CTM2012-36317) and VULCANO-II (CTM2014-51837-R) projects and funds from The Spanish Institute of Oceanography (IEO) through the VULCANA (IEO-2015-2017) project. The use of the ROV Liropus 2000 was also funded by IEO.
Acknowledgments
The authors would like to thank the officers and crew of the R/V Ramón Margalef and Ángeles Alvariño from the Spanish Institute of Oceanography for their help at sea. We would also like to thank the technician team of ACSM for their help at sea during the cruise and for the recovering of the mooring with the ROV. We are grateful to three anonymous reviewers and the journal editor for their comments, which greatly improved the quality of the paper.
Conflicts of Interest
The authors declare no conflict of interest.
References
Fricke, H.; Giere, O.; Stetter, K.; Alfredsson, G.A.; Kristjansson, J.K.; Stoffers, P.; Svavarsson, J. Hydrothermal vent communities at the shallow subpolar Mid-Atlantic ridge. Mar. Biol. 1989, 102, 425–429. [Google Scholar] [CrossRef]
Botz, R.; Winckler, G.; Bayer, R.; Schmitt, M.; Schmidt, M.; Garbe-Schönberg, D.; Stoffers, P.; Kristjansson, J.K. Origin of trace gases in submarine hydrothermal vents of the Kolbeinsey Ridge, north Iceland. Earth Planet. Sci. Lett. 1999, 171, 83–93. [Google Scholar] [CrossRef]
Dando, P.R.; Stüben, D.; Varnavas, S.P. Hydrothermalism in the Mediterranean Sea. Prog. Oceanogr. 1999, 44, 333–367. [Google Scholar] [CrossRef]
Cardigos, F.; Colaço, A.; Dando, P.R.; Ávila, S.P.; Sarradin, P.M.; Tempera, F.; Conceição, P.; Pascoal, A.; Serrão Santos, R. Shallow water hydrothermal vent field fluids and communities of the D. João de Castro Seamount (Azores). Chem. Geol. 2005, 224, 153–168. [Google Scholar] [CrossRef]
Furushima, Y.; Nagao, M.; Suzuki, A.; Yamamoto, H.; Maruyama, T. Periodic behavior of the bubble jet (Geyser) in the taketomi submarine hot springs of the southern part of yaeyama archipelago Japan. Mar. Technol. Soc. J. 2009, 43, 13–22. [Google Scholar] [CrossRef]
Butterfield, D.A.; Massoth, G.J.; McDuff, R.E.; Lupton, J.E.; Lilley, M.D. Geochemistry of hydrothermal fluids from Axial Seamount hydrothermal emissions study vent field, Juan de Fuca Ridge: Subseafloor boiling and subsequent fluid-rock interaction. J. Geophys. Res. 1990, 95, 12895–12921. [Google Scholar] [CrossRef]
Tassi, F.; Capaccioni, B.; Caramanna, G.; Cinti, D.; Montegrossi, G.; Pizzino, L.; Quattrocchi, F.; Vaselli, O. Low-pH waters discharging from submarine vents at Panarea Island (Aeolian Islands, southern Italy) after the 2002 gas blast: Origin of hydrothermal fluids and implications for volcanic surveillance. Appl. Geochem. 2009, 24, 246–254. [Google Scholar] [CrossRef]
Campbell, A.C.; Edmond, J.M. Halide systematics of submarine hydrothermal vents. Nature 1989, 342, 168–170. [Google Scholar] [CrossRef]
Thompson, G. Hydrothermal Fluxes in the Ocean. In Chemical Oceanography; Elsevier: London, UK, 1983; pp. 271–337. [Google Scholar]
Von Damm, K.L. Seafloor Hydrothermal Activity: Black Smoker Chemistry And Chimneys. Ann. Rev. Earth Planet. Sci. 1990, 18, 173–204. [Google Scholar]
Rona, P.A.; Bemis, K.G.; Jones, C.D.; Jackson, D.R.; Mitsuzawa, K.; Silver, D. Entrainment and bending in a major hydrothermal plume, Main Endeavour Field, Juan de Fuca Ridge. Geophys. Res. Lett. 2006, 33, L19313. [Google Scholar] [CrossRef]
Prol-Ledesma, R.M.; Canet, C.; Torres-Vera, M.A.; Forrest, M.J.; Armienta, M.A. Vent fluid chemistry in Bahía Concepción coastal submarine hydrothermal system, Baja California Sur, Mexico. J. Volcanol. Geotherm. Res. 2004, 137, 311–328. [Google Scholar] [CrossRef]
Wenzhöfer, F.; Holby, O.; Glud, R.N.; Nielsen, H.K.; Gundersen, J.K. In situ microsensor studies of a shallow water hydrothermal vent at Milos, Greece. Mar. Chem. 2000, 69, 43–54. [Google Scholar] [CrossRef]
Tarasov, V.G.; Gebruk, A.V.; Mironov, A.N.; Moskalev, L.I. Deep-sea and shallow-water hydrothermal vent communities: Two different phenomena? Chem. Geol. 2005, 224, 5–39. [Google Scholar] [CrossRef]
Aliani, S.; Bortoluzzi, G.; Caramanna, G.; Raffa, F. Seawater dynamics and environmental settings after November 2002 gas eruption off Bottaro (Panarea, Aeolian Islands, Mediterranean Sea). Cont. Shelf Res. 2010, 30, 1338–1348. [Google Scholar] [CrossRef]
Tudino, T.; Bortoluzzi, G.; Aliani, S. Shallow-water gaseohydrothermal plume studies after massive eruption at Panarea, Aeolian Islands, Italy. J. Mar. Syst. 2014, 131, 1–9. [Google Scholar] [CrossRef]
Heinicke, J.; Italiano, F.; Maugeri, R.; Merkel, B.; Pohl, T.; Schipek, M.; Braun, T. Evidence of tectonic control on active arc volcanism: The Panarea-Stromboli tectonic link inferred by submarine hydrothermal vents monitoring (Aeolian arc, Italy). Geophys. Res. Lett. 2009, 36, L04301. [Google Scholar] [CrossRef]
Tivey, M.K.; Bradley, A.M.; Joyce, T.M.; Kadko, D. Insights into tide-related variability at seafloor hydrothermal vents from time-series temperature measurements. Earth Planet. Sci. Lett. 2002, 202, 693–707. [Google Scholar] [CrossRef]
Bayona, J.M.; Monjonell, A.; Miquel, J.C.; Fowler, S.W.; Albaigés, J. Biogeochemical characterization of particulate organic matter from a coastal hydrothermal vent zone in the Aegean Sea. Org. Geochem. 2002, 33, 1609–1620. [Google Scholar] [CrossRef]
Tarasov, V.G.; Propp, M.V.; Propp, L.N.; Zhirmunsky, A.V.; Namsakakv, B.B.; Gorlenko, V.M.; Starynin, D.A. Shallow-Water Gasohydrothermal Vents of Ushishir Volcano and the Ecosystem of Kraternaya Bight (The Kurile Islands). Mar. Ecol. 1990, 11, 1–23. [Google Scholar] [CrossRef]
Santana-Casiano, J.M.; Fraile-Nuez, E.; González-Dávila, M.; Baker, E.T.; Resing, J.A.; Walker, S.L. Significant discharge of CO2 from hydrothermalism associated with the submarine volcano of El Hierro Island. Sci. Rep. 2016, 6, 1–9. [Google Scholar] [CrossRef]
Chance, A.; Kelly, P.M. An apparent periodicity in an index of volcanic activity. Nature 1979, 280, 671–672. [Google Scholar] [CrossRef]
Aliani, S.; Meloni, R.; Dando, P.R. Periodicities in sediment temperature time-series at a marine shallow water hydrothermal vent in Milos Island (Aegean Volcanic arc, Eastern Mediterranean). J. Mar. Syst. 2004, 46, 109–119. [Google Scholar] [CrossRef]
Spampinato, L.; Oppenheimer, C.; Cannata, A.; Montalto, P.; Salerno, G.G.; Calvari, S. On the time-scale of thermal cycles associated with open-vent degassing. Bull. Volcanol. 2012, 74, 1281–1292. [Google Scholar] [CrossRef]
Tamburello, G.; Aiuppa, A.; McGonigle, A.J.S.; Allard, P.; Cannata, A.; Giudice, G.; Kantzas, E.P.; Pering, T.D. Periodic volcanic degassing behavior: The Mount Etna example. Geophys. Res. Lett. 2013, 40, 4818–4822. [Google Scholar] [CrossRef]
Ilanko, T.; Oppenheimer, C.; Burgisser, A.; Kyle, P. Cyclic degassing of Erebus volcano, Antarctica. Bull. Volcanol. 2015, 77, 56. [Google Scholar] [CrossRef]
Chouet, B.A. Long-period volcano seismicity: Its source and use in eruption forecasting. Nature 1996, 380, 309–316. [Google Scholar] [CrossRef]
Ripepe, M.; Marchetti, E.; Bonadonna, C.; Harris, A.J.L.; Pioli, L.; Ulivieri, G. Monochromatic infrasonic tremor driven by persistent degassing and convection at Villarrica Volcano, Chile. Geophys. Res. Lett. 2010, 37, 15. [Google Scholar] [CrossRef]
Blake, S. Volatile oversaturation during the evolution of silicic magma chambers as an eruption trigger. J. Geophys. Res. 1984, 89, 8237. [Google Scholar] [CrossRef]
Dingwell, D.B. Magma degassing and fragmentation: Recent experimental advances. In From Magma to Tephra-Modelling Physical Processes of Explosive Volcanic Eruptions; Elsevier: Amsterdam, The Netherland, 1998. [Google Scholar]
Varley, N.R.; Taran, Y. Degassing processes of Popocatépetl and Volcán de Colima, Mexico. Geol. Soc. Lond. Spec. Publ. 2003, 213, 263–280. [Google Scholar] [CrossRef]
Edmonds, M.; Herd, R.A.; Galle, B.; Oppenheimer, C.M. Automated, high time-resolution measurements of SO2 flux at Soufrière Hills Volcano, Montserrat. Bull. Volcanol 2003, 65, 578–586. [Google Scholar] [CrossRef]
Pering, T.D.; Tamburello, G.; McGonigle, A.J.S.; Aiuppa, A.; Cannata, A.; Giudice, G.; Patanè, D. High time resolution fluctuations in volcanic carbon dioxide degassing from Mount Etna. J. Volcanol. Geotherm. Res. 2014, 270, 115–121. [Google Scholar] [CrossRef]
Peters, N.; Oppenheimer, C.; Killingsworth, D.R.; Frechette, J.; Kyle, P. Correlation of cycles in Lava Lake motion and degassing at Erebus Volcano, Antarctica. Geochem. Geophys. Geosyst. 2014, 15, 3244–3257. [Google Scholar] [CrossRef]
Dziak, R.P.; Baker, E.T.; Shaw, A.M. Flux measurements of explosive degassing using a yearlong hydroacoustic record at an erupting submarine volcano. Geochemistry 2012. [Google Scholar] [CrossRef]
O’Hara, S.; Dando, P.R.; Schuster, U.; Bennis, A. Gas seep induced interstitial water circulation: Observations and environmental implications. Cont. Shelf Res. 1995, 15, 931–948. [Google Scholar] [CrossRef]
Botz, R.; Stüben, D.; Winckler, G.; Bayer, R.; Schmitt, M.; Faber, E. Hydrothermal gases offshore Milos Island, Greece. Chem. Geol. 1996, 130, 161–173. [Google Scholar] [CrossRef]
Riedel, C.; Schmidt, M.; Botz, R.; Theilen, F. The Grimsey hydrothermal field offshore North Iceland: Crustal structure, faulting and related gas venting. Earth Planet. Sci. Lett. 2001, 193, 409–421. [Google Scholar] [CrossRef]
Botz, R.; Wehner, H.; Worthington, T.J.; Schmidt, M.; Stoffers, P. Thermogenic hydrocarbons from the offshore Calypso hydrothermal field, Bay of Plenty, New Zealand. Chem. Geol. 2002, 186, 235–248. [Google Scholar] [CrossRef]
De Ronde, C.E.J.; Stoffers, P.; Garbe-Schönberg, D.; Christenson, B.W.; Jones, B.; Manconi, R.; Browne, P.R.L.; Hissmann, K.; Botz, R.; Davy, B.W.; et al. Discovery of active hydrothermal venting in Lake Taupo, New Zealand. J. Volcanol. Geotherm. Res. 2002, 115, 257–275. [Google Scholar] [CrossRef]
Forrest, M.J.; Ledesma-Vázquez, J.; Ussler, W., III; Kulongoski, J.T.; Hilton, D.R.; Greene, H.G. Gas geochemistry of a shallow submarine hydrothermal vent associated with the El Requesón fault zone, Bahía Concepción, Baja California Sur, México. Chem. Geol. 2005, 224, 82–95. [Google Scholar] [CrossRef]
McCarthy, K.T.; Pichler, T.; Price, R.E. Geochemistry of Champagne Hot Springs shallow hydrothermal vent field and associated sediments, Dominica, Lesser Antilles. Chem. Geol. 2005, 224, 55–68. [Google Scholar] [CrossRef]
Hall-Spencer, J.M.; Rodolfo-Metalpa, R.; Martin, S.; Ransome, E.; Fine, M.; Turner, S.M.; Rowley, S.J.; Tedesco, D.; Buia, M.-C. Volcanic carbon dioxide vents show ecosystem effects of ocean acidification. Nature 2008, 454, 96–99. [Google Scholar] [CrossRef]
Fraile-Nuez, E.; González-Dávila, M.; Santana-Casiano, J.M.; Arístegui, J.; Alonso-González, I.J.; Hernández-León, S.; Blanco, M.J.; Rodríguez-Santana, A.; Hernández-Guerra, A.; Gelado-Caballero, M.D.; et al. Erratum: The submarine volcano eruption at the island of El Hierro: Physical-chemical perturbation and biological response. Sci. Rep. 2012, 2, 1–6. [Google Scholar] [CrossRef]
Santana-Casiano, J.M.; González-Dávila, M.; Fraile-Nuez, E.; De Armas, D.; González, A.G.; Domínguez-Yanes, J.F.; Escanez, J. The natural ocean acidification and fertilization event caused by the submarine eruption of El Hierro. Sci. Rep. 2013, 3, 1–8. [Google Scholar] [CrossRef] [PubMed]
Lomb, N.R. Least-squares frequency analysis of unequally spaced data. Astrophys. Space Sci. 1976, 39, 447–462. [Google Scholar] [CrossRef]
Scargle, J.D. Studies in astronomical time series analysis. II—Statistical aspects of spectral analysis of unevenly spaced data. The Astrophys. J. 1982, 263, 835–853. [Google Scholar] [CrossRef]
Daubechies, I. The wavelet transform, time-frequency localization and signal analysis. IEEE Trans. Inf. Theory 1990, 36, 961–1005. [Google Scholar] [CrossRef]
Fraile-Nuez, E.; Machín, F.; Vélez-Belchí, P.; López-Laatzen, F.; Borges, R.; Benítez-Barrios, V.M.; Hernández-Guerra, A. Nine years of mass transport data in the eastern boundary of the North Atlantic Subtropical Gyre. J. Geophys. Res. 2010, 115, C09009. [Google Scholar] [CrossRef]
Torrence, C.; Webster, P.J. Interdecadal changes in the ENSO-monsoon system. J. Climate 1999, 12, 2679–2690. [Google Scholar] [CrossRef]
Grinsted, A.; Moore, J.C.; Jevrejeva, S. Application of the cross wavelet transform and wavelet coherence to geophysical time series. Nonlin. Process. Geophys. 2004, 11, 1–6. [Google Scholar] [CrossRef]
Massoth, G.J.; Butterfield, D.A.; Lupton, J.E.; McDuff, R.E.; Lilley, M.D.; Jonasson, I.R. Submarine venting of phase-separated hydrothermal fluids at Axial Volcano, Juan de Fuca Ridge. Nature 1989, 340, 702–705. [Google Scholar] [CrossRef]
Staudigel, H.; Hart, S.R.; Pile, A.; Bailey, B.E.; Baker, E.T.; Brooke, S.; Connelly, D.P.; Haucke, L.; German, C.R.; Hudson, I.; et al. Vailulu’u seamount, Samoa: Life and death on an active submarine volcano. Proc. Natl. Acad. Sci. USA 2006, 103, 6448–6453. [Google Scholar] [CrossRef]
Egbert, G.D.; Bennett, A.F.; Foreman, M.G.G. TOPEX/POSEIDON tides estimated using a global inverse model. J. Geophys. Res. 1994, 99, 24821–24852. [Google Scholar] [CrossRef]
Christopoulou, M.E.; Mertzimekis, T.J.; Nomikou, P.; Papanikolaou, D.; Carey, S.; Mandalakis, M. Influence of hydrothermal venting on water column properties in the crater of the Kolumbo submarine volcano, Santorini volcanic field (Greece). Geo-Mar.Lett. 2016, 36, 15–24. [Google Scholar] [CrossRef]
Resing, J.A.; Baker, E.T.; Lupton, J.E.; Walker, S.L.; Butterfield, D.A.; Massoth, G.J.; Nakamura, K.-I. Chemistry of hydrothermal plumes above submarine volcanoes of the mariana arc. Geochem. Geophys. Geosyst. 2009, 10. [Google Scholar] [CrossRef]
Baumberger, T.; Lilley, M.D.; Resing, J.A.; Lupton, J.E.; Baker, E.T.; Butterfield, D.A.; Olson, E.J.; Früh-Green, G.L. Understanding a submarine eruption through time series hydrothermal plume sampling of dissolved and particulate constituents: West Mata, 2008–2012. Geochem. Geophys. Geosyst. 2014, 15, 4631–4650. [Google Scholar] [CrossRef]
Resing, J.A.; Rubin, K.H.; Embley, R.W.; Lupton, J.E.; Baker, E.T.; Dziak, R.P.; Baumberger, T.; Lilley, M.D.; Huber, J.A.; Shank, T.M.; et al. Active submarine eruption of boninite in the northeastern Lau Basin. Nat. Geosci. 2011, 4, 799–806. [Google Scholar] [CrossRef]
Buck, N.J.; Resing, J.A.; Baker, E.T.; Lupton, J.E. Chemical Fluxes From a Recently Erupted Shallow Submarine Volcano on the Mariana Arc. Geochem. Geophys. Geosyst. 2018, 19, 1660–1673. [Google Scholar] [CrossRef]
Tamburello, G.; Aiuppa, A.; Kantzas, E.P.; McGonigle, A.J.S.; Ripepe, M. Passive vs. active degassing modes at an open-vent volcano (Stromboli, Italy). Earth Planet. Sci. Lett. 2012, 359–360, 106–116. [Google Scholar] [CrossRef]
Bouche, E.; Vergniolle, S.; Staudacher, T.; Nercessian, A.; Delmont, J.C.; Frogneux, M.; Cartault, F.; Le Pichon, A. The role of large bubbles detected from acoustic measurements on the dynamics of Erta ‘Ale lava lake (Ethiopia). Earth Planet. Sci. Lett. 2010, 295, 37–48. [Google Scholar] [CrossRef]
Patrick, M.R.; Orr, T.; Wilson, D.; Dow, D.; Freeman, R. Cyclic spattering, seismic tremor, and surface fluctuation within a perched lava channel, Kīlauea Volcano. Bull. Volcanol. 2011, 73, 639–653. [Google Scholar] [CrossRef]
Harris, A.; Johnson, J.; Horton, K.; Garbeil, H.; Ramm, H.; Pilger, E.; Flynn, L.; Mouginis-Mark, P.; Pirie, D.; Donegan, S.; et al. Ground-based infrared monitoring provides new tool for remote tracking of volcanic activity. Eos Trans. Am. Geophys. Union 2003, 84, 409–418. [Google Scholar] [CrossRef]
Blackburn, E.A.; Wilson, L.; Sparks, R.S.J. Mechanisms and dynamics of strombolian activity. J. Geol. Soc. 1976, 132, 429–440. [Google Scholar] [CrossRef]
Schnur, S.R.; Chadwick, W.W.; Embley, R.W.; Ferrini, V.L.; De Ronde, C.E.J.; Cashman, K.V.; Deardorff, N.D.; Merle, S.G.; Dziak, R.P.; Haxel, J.H.; et al. A decade of volcanic construction and destruction at the summit of NW Rota-1 seamount: 2004–2014. J. Geophys. Res. Solid Earth 2017, 122, 1558–1584. [Google Scholar] [CrossRef]
Chevaldonné, P.; Desbruyères, D.; Haître, M.L. Time-series of temperature from three deep-sea hydrothermal vent sites. Deep Sea Res. Part. A. Oceanogr. Res. Papers 1991, 38, 1417–1430. [Google Scholar] [CrossRef]
Schultz, A.; Dickson, P.; Elderfield, H. Temporal variations in diffuse hydrothermal flow at TAG. Geophys. Res. Lett. 1996, 23, 3471–3474. [Google Scholar] [CrossRef]
Lenton, T.M. Early warning of climate tipping points. Nature Clim. Change 2011, 1, 201–209. [Google Scholar] [CrossRef]
Wilson, C.J.N. Volcanoes: Characteristics, tipping points, and those pesky unknown unknowns. Elements 2017, 13, 41–46. [Google Scholar] [CrossRef]
Ripepe, M.; Harris, A.J.L.; Marchetti, E. Coupled thermal oscillations in explosive activity at different craters of Stromboli volcano. Geophys. Res. Lett. 2005, 32, 1–4. [Google Scholar] [CrossRef]
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Figure 1. Location map. (a) Location of the island of El Hierro in the Canary Archipelago. (b) Locations of the Tagoro submarine volcano and the CTD ref. stations. (c) High resolution bathymetry of Tagoro submarine volcano. (d) High resolution bathymetry zoon at the area of the main crater vent. (e) Image from the ROV of the mooring deployed at the interior of the main crater vent before its recovery (Vulcana-II-0417).
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Figure 2. High definition images from a remotely operated vehicle (ROV) of the Spanish Institute of Oceanography at the interior of the main crater vent of Tagoro submarine volcano, between a 124–130 m depth, collected during the Vulcana-II-1118 cruise in November 2018. (a–j) show different perspectives from the degassing process in the interior of the crater with the presence of bacterial mat areas, chimneys fields, and cracks.
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Figure 3. Vertical profile of (a) potential temperature, (b) salinity, (c) potential density, and (d) pH, with their standard deviation at the reference stations not affected by the emissions of the submarine volcano. Time series of the same parameters, but recorded by the mooring at the interior of the main crater at a 127 m depth are shown in red.
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Figure 4. Time series of (a) potential temperature anomaly, (b) salinity anomaly, (c) potential density anomaly, (d) pressure, (e) pH anomaly, (f) oxidation-reduction potential (ORP), and (g) ∂(ORP)/∂t recorded by an RBR CTD and Seabird 27 pH-ORP system mounted at a mooring deployed at the interior of the main crater at a depth of 127 m during October–December 2016. (h) Theoretical tide extracted by [54]. Red color shows the five-minute moving average time series.
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Figure 5. Filtered time series of potential temperature (a1), salinity (a2), and pressure (a3) from an RBR CTD device mounted in a mooring at the interior of the main crater at a 127 m depth. (b1–b3) are the corresponding power spectra and statistical significance computed by fast Fourier transform (FFT). (c1–c3) are the application of the wavelet transform. The solid contour shows the 95% confidence interval and the light shaded region the cone of influence, representing the area where the wavelet spectrum is affected by edge effects.
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Figure 6. Filtered time series of pH (a1) and ∂(ORP)/∂t (a2) from a pH-ORP sensor mounted in a mooring at the interior of the main crater at a 127 m depth. (b1–b2) are the corresponding power spectra and statistical significance computed by fast Fourier transform (FFT). (c1–c2) are the implementation of the wavelet transform. The solid contour shows the 95% confidence interval and the light shaded region the cone of influence, representing the area where the wavelet spectrum is affected by edge effects.
Table
Table 1. Potential temperature, salinity, potential density, and pH statistics. Minimum, maximum, and mean values with their standard deviation, maximum anomalies found in the area, and ref. mean values of non-affected water at the depth of the main crater (127 m).

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