scholarly journals Low-Temperature Hydrothermal Systems Response to Rainfall Forcing: An Example From Temperature Time Series of Fumaroles at La Soufrière de Guadeloupe Volcano

2022 ◽  
Vol 9 ◽  
Author(s):  
Jean de Bremond d’Ars ◽  
Dominique Gibert

Volcanoes with highly-developed and shallow hydrothermal systems may be subject to sudden increases of their surface steam emission at vents in response to either deep forcing (e.g. increase of heat flux coming from the magma chamber) or external forcing (e.g. sudden decrease of atmospheric pressure or variation of meteoric water input). Because the vent plumbing has a limited heat and mass transfer capacity, the rise of steam pressure accompanying the increase of flux may destabilize the system in order to augment its net transfer capacity. This reorganization may, for instance, take the form of an enlargement of existing conduits and vents or to the creation of new ones. In such a case, local and extremely dangerous blast phenomena are likely to occur with devastating consequences several hundreds of meters around. Even volcanoes with a moderate activity and considered safe by the local population are exposed to such abrupt and dangerous events. The detection of early warning signals through temperature monitoring in the vents is of a primary importance and a main difficulty is to correctly interpret temperature jumps in order to reduce false alarms. We analyze time series of the temperature measured in three fumaroles located at the top of La Soufrière volcano in Guadeloupe, which are characterized by their relatively low temperature around 99°C, slightly above the boiling temperature of water at this altitude. Thanks to the long duration of the records from January to August 2017 and to their short 1-s sampling interval, a multiscale analysis can be performed over several orders of magnitude. We show that, despite their complex and sometimes erratic appearance, the temperature variations observed in the vents contain components highly correlated with rain input variations. Some remarkable patterns recurrently appear at different periods and we show that the main temperature variations of more than 10°C are related to the rainfall intensity. Our results illustrate the importance of external forcing on the otherwise complex and possibly chaotic dynamics of the shallow hydrothermal system of La Soufrière. They also reveal that a careful analysis of rainfall forcing must be done to be able to draw any conclusion concerning changes caused by the underlying hydrothermal system.

2014 ◽  
Vol 57 (3) ◽  
Author(s):  
Francesco Mazzarini ◽  
Giovanni Ruggieri ◽  
Ilaria Isola ◽  
Chiara Boschi ◽  
Andrea Dini ◽  
...  

<p>Geometric analysis of vein systems hosted in upper crustal rocks and developed in high and low temperature hydrothermal systems is presented. The high temperature hydrothermal system consists of tourmaline-rich veins hosted within the contact aureole of the upper Miocene Porto Azzurro pluton in the eastern Elba Island. The low temperature hydrothermal system consists of calcite-rich veins hosted within the Oligocene sandstones of the Tuscan Nappe, exposed along the coast in southern Tuscany. Vein thickness distribution is here used as proxy for inferring some hydraulic properties (transmissivity) of the fluid circulation at the time of veins’ formation. We derive estimations of average thickness of veins by using the observed distributions. In the case of power law thickness distributions, the lower the scaling exponent of the distribution the higher the overall transmissivity. Indeed, power law distributions characterised by high scaling exponents have transmissivity three order of magnitude lower than negative exponential thickness distribution. Simple observations of vein thickness may thus provides some clues on the transmissivity in hydrothermal systems.</p>


Author(s):  
Hsin-Fu Yeh ◽  
Hung-Hsiang Hsu

The Tatun Volcano Group (TVG) is located in northern Taiwan and consists of many springs and fumaroles. The Tayukeng (TYK) area is the most active fumarole site in the TVG. In this study, we analyzed the long-term geochemical variations of hydrothermal fluids and proposed a mechanism responsible for the variation in TYK. There are two different aquifers beneath the TYK area: a shallow SO42−-rich aquifer and a deeper aquifer rich in Cl−. TYK thermal water was mainly supplied by the shallow SO42−-rich aquifer; therefore, the thermal water showed high SO42− concentrations. After 2015, the inflow of deep thermal water increased, causing the Cl− concentrations of the TYK to increase. Notably, the inferred reservoir temperatures based on quartz geothermometry increased; however, the surface temperature of the spring decreased. We inferred that the enthalpy was lost during transportation to the surface. Therefore, the surface temperature of the spring does not increase with an increased inflow of deep hydrothermal fluid. The results can serve as a reference for understanding the complex evolution of the magma-hydrothermal system in the TVG.


2021 ◽  
Author(s):  
Arturo Magana-Mora ◽  
Mohammad AlJubran ◽  
Jothibasu Ramasamy ◽  
Mohammed AlBassam ◽  
Chinthaka Gooneratne ◽  
...  

Abstract Objective/Scope. Lost circulation events (LCEs) are among the top causes for drilling nonproductive time (NPT). The presence of natural fractures and vugular formations causes loss of drilling fluid circulation. Drilling depleted zones with incorrect mud weights can also lead to drilling induced losses. LCEs can also develop into additional drilling hazards, such as stuck pipe incidents, kicks, and blowouts. An LCE is traditionally diagnosed only when there is a reduction in mud volume in mud pits in the case of moderate losses or reduction of mud column in the annulus in total losses. Using machine learning (ML) for predicting the presence of a loss zone and the estimation of fracture parameters ahead is very beneficial as it can immediately alert the drilling crew in order for them to take the required actions to mitigate or cure LCEs. Methods, Procedures, Process. Although different computational methods have been proposed for the prediction of LCEs, there is a need to further improve the models and reduce the number of false alarms. Robust and generalizable ML models require a sufficiently large amount of data that captures the different parameters and scenarios representing an LCE. For this, we derived a framework that automatically searches through historical data, locates LCEs, and extracts the surface drilling and rheology parameters surrounding such events. Results, Observations, and Conclusions. We derived different ML models utilizing various algorithms and evaluated them using the data-split technique at the level of wells to find the most suitable model for the prediction of an LCE. From the model comparison, random forest classifier achieved the best results and successfully predicted LCEs before they occurred. The developed LCE model is designed to be implemented in the real-time drilling portal as an aid to the drilling engineers and the rig crew to minimize or avoid NPT. Novel/Additive Information. The main contribution of this study is the analysis of real-time surface drilling parameters and sensor data to predict an LCE from a statistically representative number of wells. The large-scale analysis of several wells that appropriately describe the different conditions before an LCE is critical for avoiding model undertraining or lack of model generalization. Finally, we formulated the prediction of LCEs as a time-series problem and considered parameter trends to accurately determine the early signs of LCEs.


2021 ◽  
Author(s):  
Anton Nuzhdaev

&lt;p&gt;The study of mercury receipt within volcanic activity zones and large hydrothermal systems recently causes the big interest connected with attempts of an estimation of volumes of natural mercury receipt on a daily surface.&lt;/p&gt;&lt;p&gt;The hydrothermal system connected with volcanic massif Big Semyachik is one of the largest on the territory of Kamchatka peninsula. On the surface, the hydrothermal system is manifested by three large hydrothermal fields - the Verhnee Field, the parychay Dolina, and the Northern Crater of the Central Semyachik, the heat export from which is estimated at 300 MW (Vakin, 1976). On the surface of the thermal fields hot thermal waters and powerful steam-gas jets are unloaded.&amp;#160; At the same time, due to the inaccessibility of thermal fields remain poorly studied, and in particular, there is no information on the concentrations of mercury in hydrothermal solutions.&lt;/p&gt;&lt;p&gt;During fieldwork in 2020 all types of thermal waters were sampled, chemical types of waters were established, concentrations of mercury in hydrothermal solutions: for hot thermal waters the average value of mercury was - 0.44 mcg / L, and in steam-gas jets - the average value of mercury was - 4.60 mcg / L.&lt;/p&gt;&lt;p&gt;Thus, in the course of the work the data on concentrations of mercury in hydrothermal solutions of one of the largest hydrothermal systems of Kamchatka were received for the first time.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;


2017 ◽  
Vol 202 ◽  
pp. 101-123 ◽  
Author(s):  
Karen C. Johannessen ◽  
Jan Vander Roost ◽  
Håkon Dahle ◽  
Siv H. Dundas ◽  
Rolf B. Pedersen ◽  
...  

2016 ◽  
Vol 56 (4) ◽  
pp. 533-544 ◽  
Author(s):  
N. V. Vakulenko ◽  
V. M. Kotlyakov ◽  
F. Parrenin ◽  
D. M. Sonechkin

A concept of the anthropogenic origin of the current global climate warming assumes that growth of concentration of the atmospheric carbon dioxide and other greenhouse gases is of great concern in this process. However, all earlier performed analyses of the Antarctic ice cores, covering the time interval of several glacial cycles for about 1 000 000 years, have demonstrated that the carbon dioxide concentration changes had a certain lag relative to the air temperature changes by several hundred years during every beginning of the glacial terminations as well as at endings of interglacials. In contrast to these findings, a recently published careful analysis of Antarctic ice cores (Parrenin et al., 2013) had shown that both, the carbon dioxide concentration and global temperature, varied almost synchronously during the transition from the last glacial maximum to the Holocene. To resolve this dilemma, a special technique for analysis of the paleoclimatic time series, based on the wavelets, had been developed and applied to the same carbon dioxide concentration and temperature time series which were used in the above paper of Parrenin et al., 2013. Specifically, a stack of the Antarctic δ18O time series (designated as ATS) and the deuterium Dome C – EPICA ones (dD) were compared to one another in order to: firstly, to quantitatively estimate differences between time scales of these series; and, secondly, to clear up the lead–lag relationships between different scales variations within these time series. It was found that accuracy of the mutual ATS and dD time series dating lay within the range of 80–160 years. Perhaps, the mutual dating of the temperature and carbon dioxide concentration series was even worse due to the assumed displacement of air bubbles within the ice. It made us to limit our analysis by the time scales of approximately from 800 to 6000 years. But it should be taken into account that any air bubble movement changes the time scale of the carbon dioxide series as a whole. Therefore, if a difference between variations in any temperature and the carbon dioxide time series is found to be longer than 80–160 years, and if these variations are timescale‑dependent, it means that the bubble displacements are not essential, and so these advancing and delays are characteristic of the time series being compared. Our wavelet‑based comparative and different‑scale analysis confirms that the relationships between the carbon dioxide concentration and temperature variations were essentially timescale‑dependent during the transition from the last glacial maximum to the Holocene. The carbon dioxide concentration variations were ahead of the temperature ones during transition from the glacial maximum to the Boelling – Alleroud warming as well as from the Young Drias cooling to the Holocene optimum. However, the temperature variations were ahead during the transition from the Boelling – Alleroud warming to the Young Drias cooling and during the transition from the Holocene optimum to the present‑day climate.


2009 ◽  
Vol 11 (1) ◽  
pp. 65-78 ◽  
Author(s):  
Xiaohui Yuan ◽  
Hao Nie ◽  
Yanbin Yuan ◽  
Anjun Su ◽  
Liang Wang

This paper proposes an enhanced cultural algorithm to solve the short-term generation scheduling of hydrothermal systems problem, in which differential evolution is embedded into a cultural algorithm and applies two knowledge sources to influence the variation operator of differential evolution and couples with simple selection criteria based on feasibility rules and heuristic search strategies to handle constraints in the cultural algorithm effectively. A test hydrothermal system is used to verify the feasibility and effectiveness of the proposed method. Results are compared with those of other optimization methods reported in the literature. It is shown that the proposed method is capable of yielding higher quality solutions.


Author(s):  
Oleg S. Krisak ◽  
Yuri V. Popov

The authors have established quartz and quartz-carbonate veins, the formation of which is associated with a low-temperature hydrothermal system of methane-water composition within the Seleznevsky coal-bearing region of the Folded Donbass. The article considers the features of localization of hydrothermal mineralization containing quartz with inclusions of hydrocarbons, and its potential ore content. It is established that the vein bodies are localized mainly in the near-hinge parts of the third-order brachianticlines in the central and marginal parts of the Seleznevskaya syncline. These veins form systems associated with the fracturing of the inter-layer stratification or intersecting the layers. Interplastic veins are subdivided into plate-like massive and vein-like bodies with a druze texture. The veins of the second type contain quartz crystals with hydrocarbon inclusions, referred to as &quot;diamonds of Donbass&quot;. They form a paragenetic association with dickite. In addition, calcite in the form of short-prismatic crystals is a typical associated mineral in the vein bodies among limestone strata. In the veins among the sandstone layers, the association with goethite, oxides and hydroxides of manganese is developed. Two morphological types of cinnabar were found in the vein bodies on the basis of HMS sampling, the largest number is confined to the brachianticlines of the marginal parts of the Seleznevskaya syncline. The analysis of the results indicates the prospects for identifying mercury mineralization with quartz-dickite-cinnabar type of mineralization.


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