Geothermal Activity

AbstractThis investigation was conducted to identify the content of metals in Calluna vulgaris (family Ericaceae), Empetrum nigrum (family Ericaceae), Festuca vivipara (family Poaceae) and Thymus praecox subsp. arcticus (family Lamiaceae), as well as in the soils where they were growing in eight geothermal heathlands in Iceland. Investigation into the vegetation of geothermal areas is crucial and may contribute to their proper protection in the future and bring more understanding under what conditions the plants respond to an ecologically more extreme situation. Plants from geothermally active sites were enriched with metals as compared to the same species from non-geothermal control sites (at an average from about 150 m from geothermal activity). The enriched metals consisted of Cd, Co, Cu, Fe and Ni in C. vulgaris; Cd, Mn and Ti in E. nigrum; Hg and Pb in F. vivipara; and Cd, Fe and Hg in T. praecox. Notably, C. vulgaris, E. nigrum, F. vivipara and T. praecox had remarkably high concentrations of Ti at levels typical of toxicity thresholds. Cd and Pb (except for C. vulgaris and F. vivipara) were not accumulated in the shoots of geothermal plants. C. vulgaris from geothermal and control sites was characterised by the highest bioaccumulation factor (BF) of Ti and Mn; E. nigrum and F. vivipara by the highest BF of Ti and Cr; and T. praecox by the highest BF of Ti and Zn compared to the other elements. In comparison with the other examined species, F. vivipara from geothermal sites had the highest concentration of Ti in above-ground parts at any concentration of plant-available Ti in soil.

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

10.5194/egusphere-egu21-15403 ◽

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

Hydrogen (H2) 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 H2 can be produced in soils by N2-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, H2 generated within the crust moves rapidly and escapes to the atmosphere. These characteristics make H2 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 Tenegu&#237;a eruption (1971) the most recent one. Cumbre Vieja volcano is characterized by a main north&#8211;south rift zone 20 km long, up to 1950 m in elevation and covering an area of 220 km2 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. &#160;Here we show the results of soil H2 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. H2 content was analysed later by a VARIAN CP4900 micro-GC. A simple diffusive emission mechanism was applied to compute the emission rate of H2 at each survey. Diffuse H2 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 H2 emission rate was &#8764;2.5 kg&#183;d&#8722;1 and an increase of this value was observed between 2013-2017 (&#8764;16.6 kg&#183;d&#8722;1), reaching a value of 36 kg&#183;d&#8722;1 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 H2 emission related to this unrest had been observed reaching values up to &#8764;70 kg&#183;d&#8722;1. Diffuse H2 emission surveys have demonstrated to be sensitive and excellent precursors of magmatic processes occurring at depth in Cumbre Vieja. Periodic diffuse H2 emission surveys provide valuable information to improve and optimize the detection of early warning signals of volcanic unrest at Cumbre Vieja volcano.

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Copernicus Sentinel-1 MT-InSAR, GNSS and Seismic Monitoring of Deformation Patterns and Trends at the Methana Volcano, Greece

Applied Sciences ◽

10.3390/app10186445 ◽

2020 ◽

Vol 10 (18) ◽

pp. 6445 ◽

Cited By ~ 1

Author(s):

Theodoros Gatsios ◽

Francesca Cigna ◽

Deodato Tapete ◽

Vassilis Sakkas ◽

Kyriaki Pavlou ◽

...

Keyword(s):

Land Surface ◽

Surface Deformation ◽

Ground Deformation ◽

Local Population ◽

Seasonal Fluctuation ◽

Satellite System ◽

Deformation Monitoring ◽

Persistent Scatterers ◽

Geothermal Activity ◽

Global Navigation Satellite

The Methana volcano in Greece belongs to the western part of the Hellenic Volcanic Arc, where the African and Eurasian tectonic plates converge at a rate of approximately 3 cm/year. While volcanic hazard in Methana is considered low, the neotectonic basin constituting the Saronic Gulf area is seismically active and there is evidence of local geothermal activity. Monitoring is therefore crucial to characterize any activity at the volcano that could impact the local population. This study aims to detect surface deformation in the whole Methana peninsula based on a long stack of 99 Sentinel-1 C-band Synthetic Aperture Radar (SAR) images in interferometric wide swath mode acquired in March 2015–August 2019. A Multi-Temporal Interferometric SAR (MT-InSAR) processing approach is exploited using the Interferometric Point Target Analysis (IPTA) method, involving the extraction of a network of targets including both Persistent Scatterers (PS) and Distributed Scatterers (DS) to augment the monitoring capability across the varied land cover of the peninsula. Satellite geodetic data from 2006–2019 Global Positioning System (GPS) benchmark surveying are used to calibrate and validate the MT-InSAR results. Deformation monitoring records from permanent Global Navigation Satellite System (GNSS) stations, two of which were installed within the peninsula in 2004 (METH) and 2019 (MTNA), are also exploited for interpretation of the regional deformation scenario. Geological, topographic, and 2006–2019 seismological data enable better understanding of the ground deformation observed. Line-of-sight displacement velocities of the over 4700 PS and 6200 DS within the peninsula are from −18.1 to +7.5 mm/year. The MT-InSAR data suggest a complex displacement pattern across the volcano edifice, including local-scale land surface processes. In Methana town, ground stability is found on volcanoclasts and limestone for the majority of the urban area footprint while some deformation is observed in the suburban zones. At the Mavri Petra andesitic dome, time series of the exceptionally dense PS/DS network across blocks of agglomerate and cinder reveal seasonal fluctuation (5 mm amplitude) overlapping the long-term stable trend. Given the steepness of the slopes along the eastern flank of the volcano, displacement patterns may indicate mass movements. The GNSS, seismological and MT-InSAR analyses lead to a first account of deformation processes and their temporal evolution over the last years for Methana, thus providing initial information to feed into the volcano baseline hazard assessment and monitoring system.

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Distributed acoustic sensing as a tool for exploration and monitoring: a proof-of-concept

10.5194/se-2021-37 ◽

2021 ◽

Author(s):

Nicola Piana Agostinetti ◽

Alberto Villa ◽

Gilberto Saccorotti

Keyword(s):

High Resolution ◽

Plane Wave ◽

Geothermal Field ◽

P Wave ◽

Apparent Velocity ◽

Near Surface ◽

Acoustic Sensing ◽

Geothermal Activity ◽

Distributed Acoustic Sensing ◽

Microseismic Event

Abstract. We use PoroTOMO experimental data to compare the performance of Distributed Acoustic Sensing (DAS) and geophone data in executing standard exploration and monitoring activities. The PoroTOMO experiment consists of two "seismic systems": (a) a 8.6 km long optical fibre cable deployed across the Brady geothermal field and covering an area of 1.5 x 0.5 km with 100 m long segments, and (b) an array of 238 co-located geophones with an average spacing of 60 m. The PoroTOMO experiment recorded continuous seismic data between March 10th and March 25th 2016. During such period, a ML 4.3 regional event occurred in the southwest, about 150 km away from the geothermal field, together with several microseismic local events related to the geothermal activity. The seismic waves generated from such seismic events have been used as input data in this study. For the exploration tasks, we compare the propagation of the ML 4.3 event across the geothermal field in both seismic systems in term of relative time-delay, for a number of configurations and segments. Defined the propagation, we analyse and compare the amplitude and the signal-to-noise ratio (SNR) of the P-wave in the two systems at high resolution. For testing the potential in monitoring local seismicity, we first perform an analysis of the geophone data for locating a microseismic event, based on expert opinion. Then, we a adopt different workflow for the automatic location of the same microseismic event using DAS data. For testing the potential in monitoring distant event, data from the regional earthquake are used for retrieving both the propagation direction and apparent velocity of the wavefield, using a standard plane-wave-fitting approach. Our results indicate that: (1) at a local scale, the seismic P-waves propagation and their characteristics (i.e. SNR and amplitude) along a single cable segment are robustly consistent with recordings from co-located geophones (delay-times δt ∼ 0.3 over 400 m for both seismic systems) ; (2) the interpretation of seismic wave propagation across multiple separated segments is less clear, due to the heavy contamination of scattering sources and local velocity heterogeneities; nonetheless, results from the plane-wave fitting still indicate the possibility for a consistent detection and location of the event; (3) at high-resolution (10 m), large amplitude variations along the fibre cable seem to robustly correlate with near surface geology; (4) automatic monitoring of microseismicity can be performed with DAS recordings with results comparable to manual analysis of geophone recordings (i.e. maximum horizontal error on event location around 70 m for both geophones and DAS data) ; and (5) DAS data pre-conditioning (e.g., temporal sub-sampling and channel-stacking) and dedicated processing techniques are strictly necessary for making any real-time monitoring procedure feasible and trustable.

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Geosites of interest as a geopheritage of Jalisco, Mexico. Progress

ECORFAN Journal Republic of Paraguay ◽

10.35429/ejrop.2020.10.6.8.15 ◽

2020 ◽

pp. 8-15

Author(s):

Roberto Maciel-Flores ◽

José Rosas-Elguera ◽

Laura Peña-García ◽

Celia Robles-Murguía

Keyword(s):

Volcanic Belt ◽

Tectonic Activity ◽

Central Plateau ◽

Productive Activities ◽

Geothermal Activity ◽

Wide Range ◽

Sierra Madre ◽

Abiotic Resources ◽

Geological Information ◽

Sierra Madre Del Sur

Conserving the geological heritage in Jalisco implies, identifying, classifying and substantiating the importance of geosites in Jalisco and its subsequent dissemination through geotourism. The above can contribute to the creation of geo-park (s), according to the definition and methodology of UNESCO, with the consequent economic benefit to the inhabitants of these regions. The disclosure of geological information encourages an appreciation and care of abiotic resources (rocks, minerals, fossils, morphology, soil and water), especially prior to productive activities, minimizing their damage or avoiding building in areas with geological hazards. Jalisco has a great geodiversity, compared to other states, its history begins approximately 200 million years ago, recorded in the Sierra Madre del Sur and in the Jalisco Block, the most recent volcanic and tectonic activity is recorded in the Volcanic Belt Mexican. The previous provinces, together with the Sierra Madre Occidental and the Central Plateau, contain a wide range of rocks, fossil areas of economic and cultural importance (most of 70 places) and relate the geological history and its dynamics. Geothermal activity, is present in 400 locations.

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3D and 4D seismic imaging of the Nesjavellir geothermal field, Iceland

10.5194/egusphere-egu21-2631 ◽

2021 ◽

Author(s):

Ortensia Amoroso ◽

Ferdinando Napolitano ◽

Vincenzo Convertito ◽

Raffaella De Matteis ◽

Thorbjörg Ágústsdóttir ◽

...

Keyword(s):

Power Plants ◽

Clean Energy ◽

B Value ◽

Geothermal Field ◽

Parameters Estimation ◽

Central Volcano ◽

The European Union ◽

Small Magnitude ◽

Geothermal Activity ◽

4D Seismic

The Nesjavellir geothermal field in the Northeastern part of the Hengill central volcano, South West Iceland, has been exploited since 1990. Geothermal energy is currently produced by Reykjav&#237;k Energy (OR) at two power plants around Hengill, at Nesjavellir to the northeast and at Hellishei&#240;i to the southwest. Part of the surplus geothermal water from both plants goes into injection wells, and in analogy with the nearby Hellishei&#240;i power plant the re-injection of geothermal gases into basaltic formations is planned in Nesjavellir. Currently, a test of deep fluid injection is conducted in preparation of the experimental re-injection of carbon dioxide and hydrogen sulphide. The seismicity recorded in the study area is due to volcano-tectonic processes, natural geothermal activity as well as induced seismicity due to production and injection.The aim of this work is to seismically image the production area of the Nesjavellir geothermal plant. Where the elastic properties of the propagation medium are investigated through the 3D and 4D seismic tomography and the b-value.The available dataset in Nesjavellir consists of 6906 seismic events extracted from &#205;SOR&#8217;s catalogue, with local magnitude -0.8&#8804;ML&#8804;3.8 recorded between October 2016 and June 2020. The earthquakes were relocated in a 1D velocity model optimized for the area. We used tomographic method in which the P- and S-arrival times are simultaneously inverted for earthquakes location and velocity parameters estimation. Re-located earthquakes are further analysed to image the b-value in the investigated volume. Time variations of the seismic properties of the medium are observed in terms of VP, Vs and VP/Vs ratio obtained from the 4D tomography.The results indicate that seismicity in Nesjavellir is mainly concentrated in three different clusters: two are located at shallow depths (1-2 km) while the third reaches down to 6 km depth. The three clusters of earthquakes are striking SW-NE and are all dipping to the west. Both the P- and S-velocity obtained models show lateral variation in E-W direction. A high VP/Vs ratio value is observed at shallow depths (due to low Vs values) and high VP/VS ratio is observed between 3.5 and 6 km depth (due to high VP and low Vs values). From the b-value mapping we observe low values (less than 1) at shallow depths and high values where the rate of small magnitude events is considerably higher. For each timestep we observe variations in VP and VS velocities that seem to be correlated with the fluids involved in field operation.This work has been supported by the S4CE ("Science for Clean Energy") project, funded by the European Union&#8217;s Horizon 2020 - R&I Framework Programme, under grant agreement No 764810 and by PRIN-2017 MATISSE project, No 20177EPPN2, funded by the Italian Ministry of Education and Research.

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Geothermal Gases Shape the Microbial Community of the Volcanic Soil of Pantelleria, Italy

mSystems ◽

10.1128/msystems.00517-20 ◽

2020 ◽

Vol 5 (6) ◽

Author(s):

Nunzia Picone ◽

Carmen Hogendoorn ◽

Geert Cremers ◽

Lianna Poghosyan ◽

Arjan Pol ◽

...

Keyword(s):

Microbial Community ◽

Greenhouse Gas ◽

Relative Abundance ◽

Hot Spots ◽

Microbial Community Composition ◽

Metagenomic Analysis ◽

Volcanic Soil ◽

Metabolic Potential ◽

Gas Emissions ◽

Geothermal Activity

ABSTRACT Volcanic and geothermal environments are characterized by low pH, high temperatures, and gas emissions consisting of mainly CO2 and varied CH4, H2S, and H2 contents which allow the formation of chemolithoautotrophic microbial communities. To determine the link between the emitted gases and the microbial community composition, geochemical and metagenomic analysis were performed. Soil samples of the geothermic region Favara Grande (Pantelleria, Italy) were taken at various depths (1 to 50 cm). Analysis of the gas composition revealed that CH4 and H2 have the potential to serve as the driving forces for the microbial community. Our metagenomic analysis revealed a high relative abundance of Bacteria in the top layer (1 to 10 cm), but the relative abundance of Archaea increased with depth from 32% to 70%. In particular, a putative hydrogenotrophic methanogenic archaeon, related to Methanocella conradii, appeared to have a high relative abundance (63%) in deeper layers. A variety of [NiFe]-hydrogenase genes were detected, showing that H2 was an important electron donor for microaerobic microorganisms in the upper layers. Furthermore, the bacterial population included verrucomicrobial and proteobacterial methanotrophs, the former showing an up to 7.8 times higher relative abundance. Analysis of the metabolic potential of this microbial community showed a clear capacity to oxidize CH4 aerobically, as several genes for distinct particulate methane monooxygenases and lanthanide-dependent methanol dehydrogenases (XoxF-type) were retrieved. Analysis of the CO2 fixation pathways showed the presence of the Calvin-Benson-Bassham cycle, the Wood-Ljungdahl pathway, and the (reverse) tricarboxylic acid (TCA) cycle, the latter being the most represented carbon fixation pathway. This study indicates that the methane emissions in the Favara Grande might be a combination of geothermal activity and biological processes and further provides insights into the diversity of the microbial population thriving on CH4 and H2. IMPORTANCE The Favara Grande nature reserve on the volcanic island of Pantelleria (Italy) is known for its geothermal gas emissions and high soil temperatures. These volcanic soil ecosystems represent “hot spots” of greenhouse gas emissions. The unique community might be shaped by the hostile conditions in the ecosystem, and it is involved in the cycling of elements such as carbon, hydrogen, sulfur, and nitrogen. Our metagenome study revealed that most of the microorganisms in this extreme environment are only distantly related to cultivated bacteria. The results obtained profoundly increased the understanding of these natural hot spots of greenhouse gas production/degradation and will help to enrich and isolate the microbial key players. After isolation, it will become possible to unravel the molecular mechanisms by which they adapt to extreme (thermo/acidophilic) conditions, and this may lead to new green enzymatic catalysts and technologies for industry.

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Current R & D Activities in the Study on Geosphere Stability

ASME 2010 13th International Conference on Environmental Remediation and Radioactive Waste Management, Volume 2 ◽

10.1115/icem2010-40018 ◽

2010 ◽

Author(s):

Takahiro Hanamuro ◽

Ken-Ichi Yasue ◽

Yoko Saito-Kokubu ◽

Koichi Asamori ◽

Tsuneari Ishimaru ◽

...

Keyword(s):

Prediction Model ◽

Hot Spring ◽

Active Faults ◽

Hydrogen Gas ◽

Helium Isotope ◽

Sea Level Changes ◽

Detection Techniques ◽

Geothermal Activity ◽

The Future

The Japanese islands are located in a tectonically active zone. The scientific base is required for assessing the geosphere stability for long-term isolation of radioactive waste in Japan. JAEA is promoting the establishment of investigation method for geotectonic events affecting geosphere stability and prediction model for the future changes of geological environments, that is necessary for site selection and safety assessment of the HLW geological disposal. For seismicity and faulting, detection techniques for active faults without topographic surface expression, such as using helium isotope ratios in hot spring gases or detection of hydrogen gas, and studies on the assessment of fault evolution have been developed. For volcanism and geothermal activity, heat sources for anomalous geothermal activity in non-volcanic regions are considered. Detection techniques for high-temperature fluids and magma deep underground, using geophysical and geochemical approaches, were constructed. For uplift, denudation and climatic/sea-level changes, a methodology to predict the future topographic change was developed. Also, for dating techniques as an essential part to proceed on these studies, C-14 and Be-10 dating using AMS and (U-Th)/He dating using QMS and ICP-MS have been developed. We are planning the establishment of assessment methods for geosphere stability including assessment of the activity of faults encountered in underground excavations, development of long-term prediction model of volcanism and hydrothermal activities, and hydrogeological analyses considering topographic change.

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The 2019 Eruption Dynamics and Morphology at Ebeko Volcano Monitored by Unoccupied Aircraft Systems (UAS) and Field Stations

Remote Sensing ◽

10.3390/rs12121961 ◽

2020 ◽

Vol 12 (12) ◽

pp. 1961 ◽

Cited By ~ 2

Author(s):

Thomas R. Walter ◽

Alexander Belousov ◽

Marina Belousova ◽

Tatiana Kotenko ◽

Andreas Auer

Keyword(s):

Active Volcano ◽

Tectonic Structures ◽

Field Station ◽

Digital Terrain ◽

Direct Observations ◽

Geothermal Activity ◽

Northern Kuril Islands ◽

Comprehensive Survey ◽

Aircraft System ◽

Structural Architecture

Vulcanian explosions are hazardous and are often spontaneous and direct observations are therefore challenging. Ebeko is an active volcano on Paramushir Island, northern Kuril Islands, showing characteristic Vulcanian-type activity. In 2019, we started a comprehensive survey using a combination of field station records and repeated unoccupied aircraft system (UAS) surveys to describe the geomorphological features of the edifice and its evolution during ongoing activity. Seismic data revealed the activity of the volcano and were complemented by monitoring cameras, showing a mean explosion interval of 34 min. Digital terrain data generated from UAS quadcopter photographs allowed for the identification of the dimensions of the craters, a structural architecture and the tephra deposition at cm-scale resolution. The UAS was equipped with a thermal camera, which in combination with the terrain data, allowed it to identify fumaroles, volcano-tectonic structures and vents and generate a catalog of 282 thermal spots. The data provide details on a nested crater complex, aligned NNE-SSW, erupting on the northern rim of the former North Crater. Our catalog of thermal spots also follows a similar alignment on the edifice-scale and is also affected by topography on a local scale. This paper provides rare observations at Ebeko volcano and shows details on its Vulcanian eruption style, highlighting the relevance of structural and morphologic control for the geometry of craters and tephra fallout as well as for structurally controlled geothermal activity.

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Spatial Metagenomics of Three Geothermal Sites in Pisciarelli Hot Spring Focusing on the Biochemical Resources of the Microbial Consortia

Molecules ◽

10.3390/molecules25174023 ◽

2020 ◽

Vol 25 (17) ◽

pp. 4023

Author(s):

Roberta Iacono ◽

Beatrice Cobucci-Ponzano ◽

Federica De Lise ◽

Nicola Curci ◽

Luisa Maurelli ◽

...

Keyword(s):

Hot Springs ◽

Hot Spring ◽

Microbial Community Composition ◽

Chemical Properties ◽

Microbial Consortia ◽

Comprehensive Information ◽

Geothermal Activity ◽

Terrestrial Hot Springs ◽

Metagenomic Study ◽

Mechanisms Of Adaptation

Terrestrial hot springs are of great interest to the general public and to scientists alike due to their unique and extreme conditions. These have been sought out by geochemists, astrobiologists, and microbiologists around the globe who are interested in their chemical properties, which provide a strong selective pressure on local microorganisms. Drivers of microbial community composition in these springs include temperature, pH, in-situ chemistry, and biogeography. Microbes in these communities have evolved strategies to thrive in these conditions by converting hot spring chemicals and organic matter into cellular energy. Following our previous metagenomic analysis of Pisciarelli hot springs (Naples, Italy), we report here the comparative metagenomic study of three novel sites, formed in Pisciarelli as result of recent geothermal activity. This study adds comprehensive information about phylogenetic diversity within Pisciarelli hot springs by peeking into possible mechanisms of adaptation to biogeochemical cycles, and high applicative potential of the entire set of genes involved in the carbohydrate metabolism in this environment (CAZome). This site is an excellent model for the study of biodiversity on Earth and biosignature identification, and for the study of the origin and limits of life.

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