Diffuse H2 degassing studies: a useful geochemical tool for monitoring Cumbre Vieja volcano, La Palma, Canary Islands

2021 ◽  
Author(s):  
Nemesio M. Pérez ◽  
Gladys V. Melián ◽  
Pedro A. Hernández ◽  
María Asensio-Ramos ◽  
Eleazar Padrón ◽  
...  
Keyword(s):  
Canary Islands ◽  
Emission Rate ◽  
Monitoring Program ◽  
Hydrothermal Systems ◽  
Sequential Gaussian Simulation ◽  
Homogeneous Distribution ◽  
La Palma ◽  
Soil Degassing ◽  
Geothermal Activity ◽  
Cumbre Vieja

<p>Hydrogen (H<sub>2</sub>) is one of the most abundant trace species in volcano-hydrothermal systems and is a key participant in many redox reactions occurring in the hydrothermal reservoir gas. Although H<sub>2</sub> can be produced in soils by N<sub>2</sub>-fixing and fertilizing bacteria, soils are considered nowadays as sinks of molecular hydrogen (Smith-Downey et al. 2006). Because of its chemical and physical characteristics, H<sub>2</sub> generated within the crust moves rapidly and escapes to the atmosphere. These characteristics make H<sub>2</sub> one of the best geochemical indicators of magmatic and geothermal activity at depth. Cumbre Vieja volcano (La Palma, Canary Islands) is the most active basaltic volcano in the Canaries with seven historical eruptions being Teneguía eruption (1971) the most recent one. Cumbre Vieja volcano is characterized by a main north–south rift zone 20 km long, up to 1950 m in elevation and covering an area of 220 km<sup>2</sup> with vents located at the northwest and northeast. Cumbre Vieja does not show any visible degassing (fumaroles, etc.). For that reason, the geochemical volcano monitoring program at Cumbre Vieja volcano has been focused on soil degassing surveys.  Here we show the results of soil H<sub>2</sub> emission surveys that have been carried out regularly since 2001. Soil gas samples were collected in about 600 sampling sites selected to obtain a homogeneous distribution at about 40 cm depth using a metallic probe and 60 cc hypodermic syringes and stored in 10 cc glass vials. H<sub>2</sub> content was analysed later by a VARIAN CP4900 micro-GC. A simple diffusive emission mechanism was applied to compute the emission rate of H<sub>2</sub> at each survey. Diffuse H<sub>2</sub> emission values were used to construct spatial distribution maps by using sequential Gaussian simulation (sGs) algorithm, allowing the estimation of the emission rate from the volcano. Between 2001-2003, the average diffuse H<sub>2</sub> emission rate was ∼2.5 kg·d<sup>−1</sup> and an increase of this value was observed between 2013-2017 (∼16.6 kg·d<sup>−1</sup>), reaching a value of 36 kg·d<sup>−1</sup> on June 2017, 4 month before the first recent seismic swarm in October, 2017 at Cumbre Vieja volcano. Six additional seismic swarms had occurred at Cumbre Vieja volcano (February 2018, July-August 2020; October 8-10, 2020; October 17-19, 2020, November 21, 2020 and December 23-26, 2020) and changes of diffuse H<sub>2</sub> emission related to this unrest had been observed reaching values up to ∼70 kg·d<sup>−1</sup>. Diffuse H<sub>2</sub> emission surveys have demonstrated to be sensitive and excellent precursors of magmatic processes occurring at depth in Cumbre Vieja. Periodic diffuse H<sub>2</sub> emission surveys provide valuable information to improve and optimize the detection of early warning signals of volcanic unrest at Cumbre Vieja volcano.</p>

Dynamics of diffuse carbon dioxide emissions from Cumbre Vieja volcano, La Palma, Canary Islands

2015 ◽  
Vol 77 (4) ◽  
Author(s):  
Eleazar Padrón ◽  
Nemesio M. Pérez ◽  
Fátima Rodríguez ◽  
Gladys Melián ◽  
Pedro A. Hernández ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Canary Islands ◽  
Carbon Dioxide Emissions ◽  
La Palma ◽  
Cumbre Vieja

Diffuse H2 and He degassing survey to study of hidden potential geothermal systems in La Palma, Canary Islands

2020 ◽  
Author(s):  
Fátima Rodríguez ◽  
Antonio Polo Sánchez ◽  
Katherine Dale ◽  
Chloe Codner ◽  
Alba Martín ◽  
...  
Keyword(s):  
Rift Zone ◽  
Average Distance ◽  
Hydrothermal Systems ◽  
Soil Gas ◽  
Geothermal Systems ◽  
Soil Matrix ◽  
North West ◽  
The North ◽  
La Palma ◽  
Cumbre Vieja

<p>La Palma is one of the eastern islands of the Canary Archipelago located off the West African continental margin. Volcanic activity in the last 123 ka has taken place exclusively at the southern part of the island, where Cumbre Vieja volcano has been formed. Cumbre Vieja, one of the most active basaltic volcano in the Canaries, host seven historical eruptions being Teneguía eruption (1971) the most recent one. Cumbre Vieja volcano, characterized by a main north–south rift zone 20 km long and covering an area of 220 km<sup>2</sup>, does not show any visible degassing that show the existence of active geothermal systems. For that reason, geochemical prospecting of soil gases and volatiles in the soil matrix itself of Cumbre Vieja can provide useful information to investigate the presence of permeable areas and potential upflow areas for the degassing of geothermal systems at depth.</p><p>We report herein the results of an intensive soil gas study, focused on non-reactive and/or highly mobile gases such as helium (He) and hydrogen (H<sub>2</sub>), in Cumbre Vieja, with geothermal exploration purposes. He has unique characteristics as a geochemical tracer: it is chemically inert and radioactively stable, non-biogenic, highly mobile and relatively insoluble in water. H<sub>2</sub> is one of the most abundant trace species in volcano-hydrothermal systems and is a key participant in many redox reactions occurring in the hydrothermal reservoir gas.</p><p>Soil gas samples were collected at 1,201 sites selected from June 2019 to September 2019, with an average distance between sites of ≈ 250 m, at ≈ 40 cm depth using a metallic probe. He content was analyzed by means of a quadrupole mass spectrometer (QMS; Pfeiffer Omnistar 422) and hydrogen concentrations by a micro-gas chromatograph (microGC; VARIAN CP490). Soil He concentration showed values up to 23.9 ppm with an average of 5.73 ppm. Soil H<sub>2</sub> concentrations measured ranged from typical atmospheric values (≈ 0.5 ppm) up to 19.8 ppm. The mean value measured for H<sub>2</sub> was 0.78 ppm. Although He concentration values showed high spatial variability, the highest values can be observed in the north–south rift zone of Cumbre Vieja and around the surface contact with Cumbre Nueva ridge. Spatial distribution of H<sub>2</sub> concentration showed the highest values in the north-west area of Cumbre Vieja volcano. The results showed here are useful to identify the possible existence of permeable portions of deep-seated actively degassing geothermal reservoirs. However, a multidisciplinary approach is essential to obtain additional information about possible geothermal systems underlying at Palma island with the last goal of the selection of appropriate locations for future exploratory wells.</p>

Helium emission at Cumbre Vieja volcano, La Palma, Canary Islands

2012 ◽  
Vol 312-313 ◽  
pp. 138-147 ◽  
Author(s):  
Eleazar Padrón ◽  
Nemesio M. Pérez ◽  
Pedro A. Hernández ◽  
Hirochika Sumino ◽  
Gladys Melián ◽  
...  
Keyword(s):  
Canary Islands ◽  
La Palma ◽  
Cumbre Vieja ◽  
Helium Emission

Magma storage and underplating beneath Cumbre Vieja volcano, La Palma (Canary Islands)

2005 ◽  
Vol 236 (1-2) ◽  
pp. 211-226 ◽  
Author(s):  
Andreas Klügel ◽  
Thor H. Hansteen ◽  
Karsten Galipp
Keyword(s):  
Canary Islands ◽  
Magma Storage ◽  
La Palma ◽  
Cumbre Vieja

scholarly journals How Would the Potential Collapse of the Cumbre Vieja Volcano in La Palma Canary Islands Impact the Guadeloupe Islands? Insights into the Consequences of Climate Change

Geosciences ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 56
Author(s):  
Gael E. Arnaud ◽  
Yann Krien ◽  
Stéphane Abadie ◽  
Narcisse Zahibo ◽  
Bernard Dudon
Keyword(s):  
Climate Change ◽  
Canary Islands ◽  
West Indies ◽  
Subduction Zones ◽  
Early Warning Systems ◽  
French West Indies ◽  
Related Factors ◽  
La Palma ◽  
Cumbre Vieja ◽  
The Impact

Tsunamis are among the deadliest threats to coastal areas as reminded by the recent tragic events in the Indian Ocean in 2004 and in Japan in 2011. A large number of tropical islands are indeed exposed due to their proximity to potential tsunami sources in tectonic subduction zones. For these territories, assessing tsunamis’ impact is of major concern for early warning systems and management plans. The effectiveness of inundation predictions relies, among other things, on processes engaged at the scale of the local bathymetry and topography. As part of the project C3AF that aimed to study the consequences of climate change on the French West Indies, we used the numerical model SCHISM to simulate the propagation of several potential tsunamis as well as their impacts on the Guadeloupe islands (French West Indies). Working from the findings of the most recent studies, we used the simulations of four scenarios of collapse of the Cumbre Vieja volcano in La Palma, Canary islands. We then used FUNWAVE-TVD to simulate trans-Atlantic wave propagation until they reached the Guadeloupe archipelago where we used SCHISM to assess their final impact. Inundation is quantified for the whole archipelago and detailed for the most exposed areas. Finally, in a climate change perspective, inundation is compared for different sea levels and degrees of vegetation cover deterioration using modified friction coefficients. We then discuss the results showing that climate change-related factors would amplify the impact more in the case of smaller inundation along with model limitations and assumptions.

Monitoring diffuse CO2 emissions by means of an automatic geochemical station at Cumbre Vieja volcano, La Palma, Canary Islands.

2021 ◽  
Author(s):  
José Barrancos ◽  
Claudia Rodríguez ◽  
Eleazar Padrón ◽  
Pedro A. Hernández ◽  
Germán D. Padilla ◽  
...  
Keyword(s):  
Time Series ◽  
Monitoring Program ◽  
Soil Parameters ◽  
Monitoring Site ◽  
Maximum Magnitude ◽  
North West ◽  
La Palma ◽  
Eruptive Episode ◽  
Seismic Swarms ◽  
Cumbre Vieja

<p>La Palma Island (708.3 km<sup>2</sup>) is located at the north-west and is one of the youngest (~2.0My) of the Canarian Archipelago. Volcanic activity has taken place exclusively at the southern part of the island, where Cumbre Vieja volcano, the most active basaltic volcano in the Canaries, has been constructed in the last 123 ky. Cumbre Vieja has suffered seven eruptions in the last 500 years, being the last in 1971 (Teneguía volcano). Since the last eruptive episode, Cumbre Vieja volcano has remained in a relative seismic calm that was interrupted on October 7th and 13rd, 2017, by two remarkable seismic swarms with earthquakes located beneath Cumbre Vieja volcano at depths ranging between 14 and 28 km with a maximum magnitude of 2.7. The frequency of these seismic episodes increased in 2020 with the occurrence of five more seismic swarms</p><p>As part of the volcano monitoring program of Cumbre Vieja, diffuse degassing of CO<sub>2</sub> has been continuously monitored since 2005 at the southernmost part of Cumbre Vieja according to the accumulation chamber method. The monitoring site (LPA04) was selected because it shows anomalous diffuse CO<sub>2</sub> degassing emission values with respect to the background values that had been measured in different surveys (Padrón et al., 2015). Meteorological and soil physical variables are also measured in an hourly basis and transmitted to ITER facilities about 150 Km far away.</p><p>Since its installation, CO<sub>2</sub> emissions ranged from non-detectable (<1.5 gm<sup>-2</sup>d<sup>-1</sup>) to 1,464.0 gm<sup>-2</sup>d<sup>-1</sup>. The time series was characterized by a strong variability in the measured values that are modulated mainly by the atmospheric and soil parameters. Soil moisture is the monitored parameter that explains the highest variability of the data, being the dry season (spring y summer) the period with the highest observed diffuse emission values. This behavior in the time series has changed after 2017 as an increasing trend in being observed in a good temporal agreement with the increase of seismic activity recorded. The observed diffuse CO<sub>2</sub> emissions trend in the LPA04 geochemical station support the occurrence of an upward magma migration towards a subcrustal magma reservoir beneath La Palma island.</p><p>Padrón et al., (2015). Bull Volcanol 77:28. DOI 10.1007/s00445-015-0914-2</p>

Temporal evolution of 3He/4He isotopic ratio at Dos Aguas cold mineral spring, La Palma, Canary Islands

2021 ◽  
Author(s):  
Eleazar Padrón ◽  
Nemesio M. Pérez ◽  
Gladys V. Melián ◽  
Hirochika Sumino ◽  
Mar Alonso ◽  
...  
Keyword(s):  
Canary Islands ◽  
Temporal Evolution ◽  
Volcanic Eruptions ◽  
Magma Reservoir ◽  
Maximum Magnitude ◽  
Mineral Spring ◽  
La Palma ◽  
Seismic Swarms ◽  
Cumbre Vieja ◽  
Canarian Archipelago

<p>Recent volcanic activity of La Palma island, the fifth in extension (706 km<sup>2</sup>) and the second in elevation (2,423 m a.s.l.) of the Canarian archipelago, has taken place exclusively in the last 123 ka at the southern part of the island, where Cumbre Vieja volcano, the most active basaltic volcano in the Canaries, has been constructed. A total of seven volcanic eruptions have been reported along the main north-south rift zone of Cumbre Vieja in the last 500 years. On October 7<sup>th</sup> and 13rd, 2017, two remarkable seismic swarms interrupted a seismic silence of 46 years in Cumbre Vieja volcano with earthquakes located beneath Cumbre Vieja volcano at depths ranging between 14 and 28 km with a maximum magnitude of 2.7. Five more seismic swarms were registered in 2020.</p><p><sup>3</sup>He/<sup>4</sup>He ratio has been monitored at Dos Aguas cold mineral spring in La Palma Island since 1991 to date as an important volcano monitoring tool able to provide early warning signal of future volcanic unrest episodes. Magmatic helium emission studies have demonstrated to be sensitive and excellent precursors of magmatic processes occurring at depth. The highest <sup>3</sup>He/<sup>4</sup>He ratio reported to date from the Canarian archipelago has been measured at Dos Aguas: 10.24 R<sub>A</sub> (being R<sub>A </sub>the ratio in atmospheric helium) (Padrón et al., 2015). This value is higher than any value found either in the lavas or terrestrial fluid in the Canary Islands, and indicates an important mantle contribution.<sup>  </sup>According to the temporal evolution of the magmatic component of helium at Dos Aguas, we suggest the occurrence of aseismic magma rising episodes beneath La Palma within the upper mantle towards an ephemeral magma reservoir in the period 2007-2017. However, in the period 2017-2020, magma rising have produced seismic swarms that were accompanied also by the highest <sup>3</sup>He/<sup>4</sup>He ratio measured at Dos Aguas (10.42 R<sub>A</sub>); both geochemical and geophysical signals confirm an upward magma migration towards a subcrustal magma reservoir beneath La Palma island.</p><p> </p><p>Padrón et al., (2015). Bull Volcanol 77:28. DOI 10.1007/s00445-015-0914-2</p>

scholarly journals Cumbre Vieja Volcano-Potential collapse and tsunami at La Palma, Canary Islands

2001 ◽  
Vol 28 (17) ◽  
pp. 3397-3400 ◽  
Author(s):  
Steven N. Ward ◽  
Simon Day
Keyword(s):  
Canary Islands ◽  
La Palma ◽  
Cumbre Vieja

Soil gas CO2 concentration, isotopic ratio and efflux measurements for geothermal exploration at Cumbre Vieja volcano, La Palma, Canary Islands

2020 ◽  
Author(s):  
Alba Martín Lorenzo ◽  
Banner Cole ◽  
Elizabeth Bullock ◽  
Sahlla Abassi ◽  
Lía Pitti-Pimienta ◽  
...  
Keyword(s):  
Canary Islands ◽  
Soil Co2 Efflux ◽  
Soil Gas ◽  
Geothermal System ◽  
Co2 Efflux ◽  
Soil Co2 ◽  
Geothermal Exploration ◽  
Diffuse Degassing ◽  
La Palma ◽  
Cumbre Vieja

<p>The exploration of geothermal resources on the island of La Palma, Canary Islands, was first conducted by the Spanish Geological Survey (IGME) from 1982 to 1984. These studies were focused exclusively on the southern part, where the last historical eruption, Teneguía, took place in 1971. This area still shows some geothermal features such us relatively high ground water temperatures (about 40ºC) and soil CO2 efflux values. Recent studies carried out at Cumbre Vieja volcano, the southern part of the island, on diffuse degassing, 3D gravimetry and Audio-MT probes point to promising results, although more studies are needed. We continue applying a multidisciplinary approach to obtain additional information about the geothermal system underlying at Palma island using novel techniques as well as tools which are appropriate to evaluate this system. For this reason, during summer 2019 a soil diffuse degassing research started at Cumbre Vieja volcano (220 km<sup>2</sup>) for geothermal exploration purposes. In this first phase of the diffuse degassing study about 1,200 sampling sites, with an average distance between sites of approximately 250 m were selected after taking into consideration the volcano-structural features and accessibility. In each sampling site in-situ soil CO2 efflux measurements were performed, and soil gas samples were collected at 40 cm depth for chemical and isotopic analysis. Spatial distribution of CO<sub>2</sub> efflux, statistical-graphical analysis of CO<sub>2</sub> efflux, and δ<sup>13</sup>C-CO<sub>2</sub> isotopic data to calculate and map the volcano-hydrothermal contribution of CO<sub>2</sub> were combined and used for geothermal exploration. The statistical-graphic analysis of the diffuse CO<sub>2</sub> efflux values confirms the existence of different geochemical populations showing two log-normal geochemical populations, a fact that suggests the addition of deep-seated CO<sub>2</sub>. Relatively low CO<sub>2</sub> efflux values were measured ranging from non-detected up to 72.8 g m<sup>-2 </sup>d<sup>-1</sup>, with an average value of 4.6 g m<sup>-2 </sup>d<sup>-1</sup>. The highest CO<sub>2</sub> efflux values were measured at the north end of Cumbre Vieja, around the surface contact with Cumbre Nueva ridge. The CO<sub>2</sub> isotopic composition, expressed as δ<sup>13</sup>C- CO<sub>2</sub> showed the contribution of three different end-members: biogenic, atmospheric and deep-seated CO<sub>2</sub>. The results indicate that most of the sampling sites exhibited CO<sub>2</sub> composed by different mixtures between atmospheric and biogenic CO<sub>2</sub> with slight inputs of deep-seated CO<sub>2</sub>, with a mean value of -15.3‰, being the maximum and the minimum -2.8‰ and -25.4‰ respectively. The results showed here can help to identify the existence of zones where deep-seated actively degassing from geothermal reservoirs occurs, particularly where the interpretation and application of geophysical data might be difficult.</p>

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