Tectonic hydrogen and tectonic oxygen production through deforming piezoelectric minerals in the presence of water

2022 ◽  
Author(s):  
Huifang Xu ◽  
Kuang-Sheng Hong ◽  
Meiye Wu ◽  
Seungyeol Lee
Keyword(s):  
Dissolved Oxygen ◽  
Subduction Zones ◽  
Atmospheric Oxygen ◽  
Mechanical Energy ◽  
Active Faults ◽  
Historical Earthquakes ◽  
Hydrogen Gas ◽  
Water Decomposition ◽  
High Concentration ◽  
Transform Faults

ABSTRACT A high concentration of hydrogen gas occurs in fracture zones of active faults that are associated with historical earthquakes. To explain the described phenomenon, we propose the piezoelectrochemical (PZEC) effect as a mechanism for the direct conversion of mechanical energy to chemical energy. When applied to natural piezoelectric crystals including quartz and serpentine, hydrogen and oxygen are generated via direct water decomposition. Laboratory experiments show H2 gas is generated from strained piezoelectric material due to the extremely low solubility of H2, suggesting that the deformed or strained mineral surfaces can catalyze water decomposition. If the strain-induced H2 production is significant, hydrogen measurements at monitoring sites can offer information on deformation of rocks operating at depth prior to earthquakes. Oxygen can be measured in water due to its high solubility compared to hydrogen. Our experimental results demonstrate that dissolved oxygen generated from the PZEC effect can oxidize dissolved organic dye and ferrous iron in an aqueous Fe(II)–silicate metal complex. The hydrogen and oxygen formed through stoichiometric decomposition of water in the presence of strained or deformed minerals in fault zones (including subduction zones and transform faults) may be referred to as tectonic hydrogen and tectonic oxygen. Tectonic hydrogen could be a potential energy source for deep subsurface and glacier-bedrock interface microbial communities that rely on molecular hydrogen for metabolism. Tectonic oxygen may have been an important oxidizing agent when dissolved in water during times in early Earth history when atmospheric oxygen levels were extremely low. Reported “whiffs” of dissolved oxygen before the Great Oxidation Event might have been related to tectonic activity.

Thermal Ageing of Some Insulating Fluids in Contact with Insulation Paper and Copper

2018 ◽  
Vol 68 (12) ◽  
pp. 2881-2885
Author(s):  
Iosif Lingvay ◽  
Gabriela Oprina ◽  
Livia Carmen Ungureanu ◽  
Alexandra Pica ◽  
Valerica Stanoi
Keyword(s):  
Experimental Data ◽  
Dissolved Oxygen ◽  
Copper Foil ◽  
Atmospheric Oxygen ◽  
Thermal Ageing ◽  
Dissolved Oxygen Concentration ◽  
Mineral Oils ◽  
Synthetic Ester ◽  
Cu2o Film ◽  
Transformer Oils

The behaviour of copper and insulation paper in various electrical insulating fluids (transformer oils) exposed to thermal ageing at 110�30C for 1000 hours in closed vessels (without access to atmospheric oxygen) has been studied. The processing of the comparative experimental data revealed in all cases that the concentration of dissolved oxygen in the investigated oils decreases exponentially during the heat treatment. In the presence of the copper foil, the oxygen is almost depleted (the dissolved oxygen concentration is approaching zero), indicating a higher affinity of the copper to oxygen than the affinity to oxygen of the investigated oils. In the presence of the copper foil and / or of the insulation paper, the degradation processes of the mineral oils have a pronounced character, explained by the catalytic activity of the Cu2O film that has been formed and by the paper degradation, respectively. A high thermo-oxidative stability was noticed in the case of natural triglyceride oils, particularly for the synthetic ester-based oil.

Automated sequencing batch bioreactor under extreme peaks of 4-chlorophenol

2003 ◽  
Vol 47 (10) ◽  
pp. 175-181 ◽  
Author(s):  
G. Buitrón ◽  
M.-E. Schoeb ◽  
J. Moreno
Keyword(s):  
Dissolved Oxygen ◽  
Metabolic Activity ◽  
Automated System ◽  
Stable Operation ◽  
High Concentration ◽  
Batch Bioreactor ◽  
On Line ◽  
The Moment ◽  
And Control ◽  
System Operating

The operation of a sequencing batch bioreactor is evaluated when high concentration peaks of a toxic compound (4-chlorophenol, 4CP) are introduced into the reactor. A control strategy based on the dissolved oxygen concentration, measured on line, is utilized. To detect the end of the reaction period, the automated system search for the moment when the dissolved oxygen has passed by a minimum, as a consequence of the metabolic activity of the microorganisms and right after to a maximum due to the saturation of the water (similar to the self-cycling fermentation, SCF, strategy). The dissolved oxygen signal was sent to a personal computer via data acquisition and control using MATLAB and the SIMULINK package. The system operating under the automated strategy presented a stable operation when the acclimated microorganisms (to an initial concentration of 350 mg 4CP/L), were exposed to a punctual concentration peaks of 600 mg 4CP/L. The 4CP concentrations peaks superior or equals to 1,050 mg/L only disturbed the system from a short to a medium term (one month). The 1,400 mg/L peak caused a shutdown in the metabolic activity of the microorganisms that led to the reactor failure. The biomass acclimated with the SCF strategy can partially support the variations of the toxic influent since, at the moment in which the influent become inhibitory, there is a failure of the system.

Magnetite (U-Th-Sm)/He dating: analytical challenges and application

2021 ◽  
Author(s):  
Marianna Corre ◽  
Martine Lanson ◽  
Arnaud Agranier ◽  
Stephane Schwartz ◽  
Fabrice Brunet ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Subduction Zones ◽  
Major Elements ◽  
Western Alps ◽  
Planetary Science ◽  
Mantle Xenoliths ◽  
Transform Faults ◽  
Geological Processes ◽  
History Of ◽  
Geochronological Constraints

<p>Magnetite (U-Th-Sm)/He dating method has a strong geodynamic significance, since it provides geochronological constraints on serpentinization episodes, which are associated to important geological processes such as ophiolite obductions, subduction zones, transform faults and fluid circulations. Although helium content that range from 0.1 pmol/g to 20 pmol/g can routinely be measured, the application of this dating technique however is still limited due to major analytical obstacles. The dissolution of a single magnetite crystal and the measurement of the U, Th and Sm present at the ppb level in the corresponding solution, remains highly challenging, especially because of the absence of magnetite standard. In order to overcome these analytical issues, two strategies have been followed, and tested on magnetite from high-pressure rocks from the Western Alps (Schwartz et al., 2020). Firstly, we purified U, Th and Sm (removing Fe and other major elements) using ion exchange columns in order to analyze samples, using smaller dilution. Secondly, we performed in-situ analyzes by laser-ablation-ICPMS. Since no solid magnetite certified standard is yet available, we synthetized our own by precipitating magnetite nanocrystals. The first quantitative results obtained by LA-ICP-MS using this synthetic material along with international glass standards, are promising. The laser-ablation technique overcomes the analytical difficulties related to sample dissolution and purification. It thus opens the path to the dating of magnetite (and also spinels) in various ultramafic rocks such as mantle xenoliths or serpentinized peridotites in ophiolites.</p><p>Schwartz S., Gautheron C., Ketcham R.A., Brunet F., Corre M., Agranier A., Pinna-Jamme R., Haurine F., Monvoin G., Riel N., 2020, Unraveling the exhumation history of high-press ure ophiolites using magnetite (U-Th-Sm)/He thermochronometry. Earth and Planetary Science Letters 543 (2020) 116359.</p>

Seismic moment catalog of large shallow earthquakes, 1900 to 1989

1992 ◽  
Vol 82 (3) ◽  
pp. 1306-1349 ◽  
Author(s):  
Javier F. Pacheco ◽  
Lynn R. Sykes
Keyword(s):  
Seismic Moment ◽  
Subduction Zones ◽  
B Value ◽  
Reference List ◽  
Transform Faults ◽  
Shallow Earthquakes ◽  
Seismicity Rates ◽  
Chile Earthquake ◽  
The Moment ◽  
Earthquake Process

Abstract We compile a worldwide catalog of shallow (depth < 70 km) and large (Ms ≥ 7) earthquakes recorded between 1900 and 1989. The catalog is shown to be complete and uniform at the 20-sec surface-wave magnitude Ms ≥ 7.0. We base our catalog on those of Abe (1981, 1984) and Abe and Noguchi (1983a, b) for events with Ms ≥ 7.0. Those catalogs, however, are not homogeneous in seismicity rates for the entire 90-year period. We assume that global rates of seismicity are constant on a time scale of decades and most inhomogeneities arise from changes in instrumentation and/or reporting. We correct the magnitudes to produce a homogeneous catalog. The catalog is accompanied by a reference list for all the events with seismic moment determined at periods longer than 20 sec. Using these seismic moments for great and giant earthquakes and a moment-magnitude relationship for smaller events, we produce a seismic moment catalog for large earthquakes from 1900 to 1989. The catalog is used to study the distribution of moment released worldwide. Although we assumed a constant rate of seismicity on a global basis, the rate of moment release has not been constant for the 90-year period because the latter is dominated by the few largest earthquakes. We find that the seismic moment released at subduction zones during this century constitutes 90% of all the moment released by large, shallow earthquakes on a global basis. The seismic moment released in the largest event that occurred during this century, the 1960 southern Chile earthquake, represents about 30 to 45% of the total moment released from 1900 through 1989. A frequency-size distribution of earthquakes with seismic moment yields an average slope (b value) that changes from 1.04 for magnitudes between 7.0 and 7.5 to b = 1.51 for magnitudes between 7.6 and 8.0. This change in the b value is attributed to different scaling relationships between bounded (large) and unbounded (small) earthquakes. Thus, the earthquake process does have a characteristic length scale that is set by the downdip width over which rupture in earthquakes can occur. That width is typically greater for thrust events at subduction zones than for earthquakes along transform faults and other tectonic environments.

scholarly journals Empirical Relationship for Assessing the Near-Field Horizontal Coseismic Displacement Using GPS Seismology Data

2021 ◽  
Vol 60 (1) ◽  
pp. 31-50
Author(s):  
Ryad Darawcheh ◽  
Riad Al Ghazzi ◽  
Mohamad Khir Abdul-wahed
Keyword(s):  
Near Field ◽  
Empirical Relationship ◽  
Active Faults ◽  
Historical Earthquakes ◽  
Dead Sea ◽  
Fault System ◽  
Coseismic Displacement ◽  
Data Set ◽  
Earthquake Parameters ◽  
Gps Station

In this research, a data set of horizontal GPS coseismic displacement in the near-field has been assembled around the world in order to investigate a potential relationship between the displacement and the earthquake parameters. Regression analyses have been applied to the data of 120 interplate earthquakes having the magnitude (Mw 4.8-9.2). An empirical relationship for prediction near-field horizontal GPS coseismic displacement as a function of moment magnitude and the distance between hypocenter and near field GPS station has been established using the multi regression analysis. The obtained relationship allows assessing the coseismic displacements associated with some large historical earthquakes occurred along the Dead Sea fault system. Such a fair relationship could be useful for assessing the coseismic displacement at any point around the active faults.

scholarly journals Current Plate Motions

1988 ◽  
Vol 129 ◽  
pp. 351-352
Author(s):  
Richard Gordon ◽  
Charles Demets ◽  
Seth Stein ◽  
Don Argus ◽  
Dale Woods
Keyword(s):  
Subduction Zones ◽  
Continental Drift ◽  
Geophysical Data ◽  
Plate Motion ◽  
Plate Boundaries ◽  
Transform Faults ◽  
Plate Motions ◽  
Motion Data ◽  
Motion Models ◽  
Self Consistent

The standard against which VLBI measurements of continental drift and plate motions are compared are self-consistent global models of “present-day” plate motions determined from geophysical data: marine magnetic anomalies at oceanic spreading centers, azimuths of transform faults, and orientations of earthquake slip vectors on transform faults and at subduction zones. Past global plate motion models have defined regions where the assumption that plates behave rigidly has apparently lead to systematic misfits, sometimes exceeding 10 mm/yr, of plate motion data. Here, we present some of the results from NUVEL-1, a new, self-consistent global model of present-day relative plate motions determined from a compilation and analysis of existing and new geophysical data. These data and new techniques have allowed us to eliminate nearly all statistically significant systematic misfits identified by earlier models, suggesting that the rigid-plate assumption is an excellent approximation when plate motions are averaged over several million years. Beside improving estimates of the motion on previously identified plate boundaries, we have also identified and determined motions on other boundaries whose subtle morphologies, lack of seismicity, and very slow (< 10 mm/yr) relative motions have made them difficult to detect. Here we focus on the application of VLBI measurements to help resolve plate tectonic problems and then briefly outline our results for Pacific-North America motion and plate motions in the Indian Ocean.

Current R & D Activities in the Study on Geosphere Stability

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.

scholarly journals Seismic damage to ancient monuments in Chiang Saen (Northern Thailand): implication for historical earthquakes in Golden Triangle area

2019 ◽  
Vol 377 (2155) ◽  
pp. 20180255 ◽  
Author(s):  
Teraphan Ornthammarath
Keyword(s):  
Eighteenth Century ◽  
Large Scale ◽  
Seismic Vulnerability ◽  
Active Faults ◽  
Lao Pdr ◽  
Historical Earthquakes ◽  
Geological Evidence ◽  
Ground Shaking ◽  
Golden Triangle ◽  
Ancient Monuments

Over the last few decades, three moderate earthquakes (Mw greater than 6.0) occurred in and around the Golden Triangle area (including Myanmar, Thailand and Lao PDR) causing unprecedented damage and loss of lives in the epicentral region. In addition to the damage to modern structures, most heritage structures in Chiang Saen, a major city of the Lan Na kingdom (from the thirteenth to the eighteenth century), were also affected. This work is intended to present observed historical structure damage from recent earthquakes, which could provide evidence for the severity of historical earthquakes from the thirteenth to the eighteenth century. Based on historical records, geological evidence and observed damage to ancient monuments in this historic town, existing heritage stupas and temples constructed since the fourteenth century sustained only minor to moderate damage from these historical earthquakes. Considering the seismic vulnerability of these historical monuments, Chiang Saen might have never been subjected to severe ground shaking greater than MMI intensity VII, similar to the major earthquake in 460 A.D. along the Mae Chan fault, which was responsible for the large-scale liquefaction and inundation of ancient Yonok town. This information could be important for paleoseismological and historical earthquake research to constrain the recurrence interval of major active faults in this area. This article is part of the theme issue ‘Environmental loading of heritage structures’.

Complexity of low-frequency earthquakes activity in western Shikoku

2020 ◽  
Author(s):  
Natalia Poiata ◽  
Jean-Pierre Vilotte ◽  
Nikolai Shapiro ◽  
Mariano Supino ◽  
Kazushige Obara
Keyword(s):  
Subduction Zones ◽  
Large Scale ◽  
Active Faults ◽  
Low Frequency ◽  
Space Time ◽  
Interaction Patterns ◽  
Slow Slip Events ◽  
Time Activity ◽  
Tectonic Tremor ◽  
Slow Earthquakes

&lt;p&gt;Short-duration transient seismic events known as low-frequency earthquakes (LFEs) are a component of the slow earthquakes family observed in the transition zone, at the root of seismogenic regions of the subduction zones or active faults. LFEs are the signature of impulse seismic energy radiation associated to and often mixed within complex tectonic tremor signal. Detailed analysis and characterization of LFE space-time activity in relation to other slow earthquake phenomena can provide important information about the state and the processes of fault interface.&lt;/p&gt;&lt;p&gt;We derive a catalog of LFEs in western Shikoku (Japan) by applying a full waveform coherency-based detection and location method to the 4-year continuous data covering the period of 2013-2016 and recorded at Hi-net seismic stations of NIED. The obtained catalog of over 150,000 detected events allows looking into the details of LFE space-time activity during the tectonic tremor sequences and inter-sequence periods.&lt;/p&gt;&lt;p&gt;We use this catalogue of LFEs to perform a systematic statistical analysis of the event occurrence patterns by applying correlation and clustering analysis to infer the large-scale (long temporal ~ 1-2 day duration) space-time characteristics and interaction patterns of activity and its potential relation to the structural complexity of the subducting plate. We also analyze the correlation between the migration of clustered LFE activity during energetic tremor sequences and short-term slow slip events occurring in the area during the analyzed period.&lt;/p&gt;

scholarly journals Dynamic Hydrogen Production from Methanol/Water Photo-Splitting Using Core@Shell-Structured CuS@TiO2Catalyst Wrapped by High Concentrated TiO2Particles

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Younghwan Im ◽  
Sora Kang ◽  
Kang Min Kim ◽  
Taeil Ju ◽  
Gi Bo Han ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Reduction Potential ◽  
Hydrogen Gas ◽  
Electronic Transitions ◽  
Core Shell ◽  
High Concentration ◽  
Visible Absorption ◽  
Long Wavelength ◽  
The Core ◽  
Uv Visible

This study focused on the dynamic hydrogen production ability of a core@shell-structured CuS@TiO2photocatalyst coated with a high concentration of TiO2particles. The rectangular-shaped CuS particles, 100 nm in length and 60 nm in width, were surrounded by a high concentration of anatase TiO2particles (>4~5 mol). The synthesized core@shell-structured CuS@TiO2particles absorbed a long wavelength (a short band gap) above 700 nm compared to that pure TiO2, which at approximately 300 nm, leading to easier electronic transitions, even at low energy. Hydrogen evolution from methanol/water photo-splitting over the core@shell-structured CuS@TiO2photocatalyst increased approximately 10-fold compared to that over pure CuS. In particular, 1.9 mmol of hydrogen gas was produced after 10 hours when 0.5 g of 1CuS@4TiO2was used at pH = 7. This level of production was increased to more than 4-fold at higher pH. Cyclic voltammetry and UV-visible absorption spectroscopy confirmed that the CuS in CuS@TiO2strongly withdraws the excited electrons from the valence band in TiO2because of the higher reduction potential than TiO2, resulting in a slower recombination rate between the electrons and holes and higher photoactivity.

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