scholarly journals The relations between seismically active and electrically conductive zones

1997 ◽  
Vol 40 (2) ◽  
Author(s):  
I. G. Kissin ◽  
A. I. Ruzajkin
Keyword(s):  
Electrical Conductivity ◽  
Probable Mechanism ◽  
Tien Shan ◽  
Strained State ◽  
Sharp Drop ◽  
Electrically Conductive ◽  
Earthquake Sources ◽  
Active Zones ◽  
Northern Tien Shan ◽  
Vast Area

The higher electrical conductivity of rocks in the middle and lower parts of the Earth's crust is generally related to the presence of fluids in rocks. The metamorphic processes of dehydration contribute to release of fluids, above all, water; these processes are also responsible for an increase in rock porosity and fracturing. These processes influence the stressed-strained state of the medium under specific conditions. A probable mechanism of earthquake source formation on the contact of blocks with different rates of dehydration and, consequently, different electrical conductivity is discussed. The spatial positions of electrically conductive and seismically active zones are correlated and definite relations between them are found with special reference to the vast area of the Northern Tien Shan within Kirgizstan and some other regions. The greatest concentration of earthquake sources is observed mainly near the contacts between blocks with contrastingly different electrical conductivity values and on sites with a sharp drop in conductive-layer depths.

Conceptual model of a lens in the upper crust determined from joint analysis of petrophysical models (Northern Tien Shan case study)

2020 ◽  
Author(s):  
Viacheslav Spichak ◽  
Alexandra Goidina
Keyword(s):  
Electrical Conductivity ◽  
Conceptual Model ◽  
Supercritical Fluids ◽  
Tien Shan ◽  
Joint Analysis ◽  
Integrated Analysis ◽  
High Porosity ◽  
High Electrical Conductivity ◽  
Fluid Saturation ◽  
Northern Tien Shan

<p>A lens having a diameter of about 40 km and a thickness of 10 km was determined at depths 14-22 km in the junction of the Kyrgyz Range and the Chu Basin Depression Trough of the Northern Tien Shan area by 3D seismic tomography carried out earlier. The following questions are still unanswered: </p><p>- what are its petrophysical characteristics?</p><p>- what is the nature of the geophysical anomalies?</p><p>- what is the mechanism of its formation?</p><p>- how long does it exist within their present boundaries?</p><p>In order to address these key issues, it is insufficient to analyze the depth behavior of the P-waves velocities as it was done before. To this end we have built additionally the electrical resistivity, density, lithotypes, temperature, porosity, and fluid saturation models along the N-S collocated seismic and magnetotelluric profile intersecting the study area.</p><p>Their integrated analysis enabled to propose a conceptual model of a lens in the Earth’s crust which answers the questions enumerated above.  In particular, it was determined that the lens is characterized by low V<sub>P</sub> and V<sub>S</sub> velocities and their ratio V<sub>P </sub>/ V<sub>S</sub>;  low resistivity (3–30 Ω.m); low density (at most 2.45 g/cm<sup>3</sup>); high porosity (above 1.2%) and fluid saturation (above 0.1%); pressure range of 4–6 Kbar; temperature range from T<sub>SCF</sub>  = 350-400°C at the lens’ top to T<sub>BDT</sub>  = 600–650°C at the bottom, characteristic for the emergence of supercritical fluids and for the solidus of granite, respectively; presence of a cap (a relatively dense, poorly permeable zone) that shields the forming fluid reservoir from above.</p><p>Joint analysis of these models made it possible to rule out the molten rocks as a responsible factor for high electrical conductivity and, with a high degree of confidence, assume supercritical fluid nature of the observed petrophysical anomalies. It was supposed that the lens is most likely to be a giant reservoir of supercritical fluids located at the depths between isotherms  T<sub>SCF </sub> and  T<sub>BDT</sub> corresponding to the PT-conditions of existence of supercritical fluids, on the one hand, and granite solidus (brittle / ductile transition), on the other hand.</p><p>The mechanism of its formation could be explained by dehydration of amphibolites accompanied by dissolution of chlorides which, in turn, leads to the emergence of films with sufficiently high electrical conductivity typical of supercritical highly mineralized solutions. Although this formation scenario fairly well explains the observed anomalies, it does not exclude another mechanism associated with the partially melted material risen from the large depths.</p><p>The lens lifetime was determined from properties of the cap. Assuming that for the Cenozoic folding regions, the rock permeability is around 10<sup>-21</sup> m<sup>2</sup> we could roughly estimate the rate of fluid migration through it. Accordingly the lens lifetime is around 33 million years which is consistent with the age of the Cenozoic activation zones.</p>

Computational technologies in seismological research (on the example of KNET, Northern Tian Shan)

2020 ◽  
Author(s):  
N.A. Sycheva
Keyword(s):  
Graduate Students ◽  
Seismic Data ◽  
Test Site ◽  
Tien Shan ◽  
Strained State ◽  
Determination Of Parameters ◽  
Northern Tien Shan ◽  
Young Researchers

The results of long-term seismological investigations have been represented in the manuscript, which were obtained by the data of the seismological network KNET established in 1991 in Northern Tien Shan. Use of various tools for processing of the obtained seismic data allowed solving a number of seismological problems, such as assessment of kinematic and dynamic parameters of earthquakes, determination of parameters of the stress – strained state of the of the crust. The new results describing in details the determinations of various indicators of seismicity in the territory of the Bishkek geodynamic test site, Northern Tien Shan have been presented. The book will be useful to the young researchers and graduate students working in the field of Earth Sciences.

scholarly journals STUDY OF THE DEPTH STRUCTURE OF SEISMICALLY ACTIVE ZONES BY THE METHOD OF MAGNETOTELLURIC SOUNDING

2021 ◽  
Vol 1 ◽  
pp. 137-143
Author(s):  
Elena A. Bataleva
Keyword(s):  
Deep Structure ◽  
Test Site ◽  
Tien Shan ◽  
Magnetotelluric Soundings ◽  
Mountain Ranges ◽  
Transition Zones ◽  
Conductivity Anomalies ◽  
Active Zones ◽  
Intermontane Basins ◽  
Northern Tien Shan

The paper presents the results of the analysis of data from magnetotelluric soundings performed in 2003-2020. A comparison of geoelectric models for the Chui and Kochkor basins of the Northern Tien Shan is shown. The main objective of the study is to identify patterns in the distribution of geoelectric inhomogeneities in the deep structure of the Bishkek geodynamic test site. Particular attention in geoelectric models was paid to the study of key objects of transition zones from mountain ranges to intermontane basins. The nature of crustal electrical conductivity anomalies is considered.

scholarly journals STUDY OF THE DEPTH STRUCTURE OF SEISMICALLY ACTIVE ZONES BY THE METHOD OF MAGNETOTELLURIC SOUNDING

2021 ◽  
Vol 2 (1) ◽  
pp. 345-353
Author(s):  
Elena A. Bataleva
Keyword(s):  
Deep Structure ◽  
Test Site ◽  
Tien Shan ◽  
Magnetotelluric Soundings ◽  
Mountain Ranges ◽  
Transition Zones ◽  
Conductivity Anomalies ◽  
Active Zones ◽  
Intermontane Basins ◽  
Northern Tien Shan

The paper presents the results of the analysis of data from magnetotelluric soundings performed in 2003-2020. A comparison of geoelectric models for the Chui and Kochkor basins of the Northern Tien Shan is shown. The main objective of the study is to identify patterns in the distribution of geoelectric inhomogeneities in the deep structure of the Bishkek geodynamic test site. Particular attention in geoelectric models was paid to the study of key objects of transition zones from mountain ranges to intermontane basins. The nature of crustal electrical conductivity anomalies is considered.

Polypyrrole/PU hybrid hydrogels: electrically conductive and fast self-healing for the potential application in body-monitor sensor

2021 ◽  
Author(s):  
Zhanyu Jia ◽  
Guangyao Li ◽  
Juan Wang ◽  
shouhua Su ◽  
Jie Wen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Potential Application ◽  
Self Healing ◽  
Electrically Conductive ◽  
Sensor Application ◽  
Hybrid Hydrogels ◽  
Health Monitor

Conductivity, self-healing and moderate mechanical properties are necessary for multifunctional hydrogels which have great potential in health-monitor sensor application. However, the combination of electrical conductivity, self-healing and good mechanical properties...

scholarly journals High Mountain Asian glacier response to climate revealed by multi-temporal satellite observations since the 1960s

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Atanu Bhattacharya ◽  
Tobias Bolch ◽  
Kriti Mukherjee ◽  
Owen King ◽  
Brian Menounos ◽  
...  
Keyword(s):  
Mass Loss ◽  
River Flow ◽  
Tien Shan ◽  
High Mountain ◽  
Glacier Mass Balance ◽  
Temperature And Precipitation ◽  
Multi Temporal ◽  
The 1960S ◽  
Northern Tien Shan

AbstractKnowledge about the long-term response of High Mountain Asian glaciers to climatic variations is paramount because of their important role in sustaining Asian river flow. Here, a satellite-based time series of glacier mass balance for seven climatically different regions across High Mountain Asia since the 1960s shows that glacier mass loss rates have persistently increased at most sites. Regional glacier mass budgets ranged from −0.40 ± 0.07 m w.e.a−1 in Central and Northern Tien Shan to −0.06 ± 0.07 m w.e.a−1 in Eastern Pamir, with considerable temporal and spatial variability. Highest rates of mass loss occurred in Central Himalaya and Northern Tien Shan after 2015 and even in regions where glaciers were previously in balance with climate, such as Eastern Pamir, mass losses prevailed in recent years. An increase in summer temperature explains the long-term trend in mass loss and now appears to drive mass loss even in regions formerly sensitive to both temperature and precipitation.

scholarly journals Electrically Conductive Networks from Hybrids of Carbon Nanotubes and Graphene Created by Laser Radiation

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1875
Author(s):  
Alexander Yu. Gerasimenko ◽  
Artem V. Kuksin ◽  
Yury P. Shaman ◽  
Evgeny P. Kitsyuk ◽  
Yulia O. Fedorova ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Laser Irradiation ◽  
Flexible Electronics ◽  
Threshold Energy ◽  
Wavelength Region ◽  
Hybrid Nanostructures ◽  
Graphene Sheets ◽  
Electrically Conductive ◽  
Walled Carbon Nanotubes

A technology for the formation of electrically conductive nanostructures from single-walled carbon nanotubes (SWCNT), multi-walled carbon nanotubes (MWCNT), and their hybrids with reduced graphene oxide (rGO) on Si substrate has been developed. Under the action of single pulses of laser irradiation, nanowelding of SWCNT and MWCNT nanotubes with graphene sheets was obtained. Dependences of electromagnetic wave absorption by films of short and long nanotubes with subnanometer and nanometer diameters on wavelength are calculated. It was determined from dependences that absorption maxima of various types of nanotubes are in the wavelength region of about 266 nm. It was found that contact between nanotube and graphene was formed in time up to 400 fs. Formation of networks of SWCNT/MWCNT and their hybrids with rGO at threshold energy densities of 0.3/0.5 J/cm2 is shown. With an increase in energy density above the threshold value, formation of amorphous carbon nanoinclusions on the surface of nanotubes was demonstrated. For all films, except the MWCNT film, an increase in defectiveness after laser irradiation was obtained, which is associated with appearance of C–C bonds with neighboring nanotubes or graphene sheets. CNTs played the role of bridges connecting graphene sheets. Laser-synthesized hybrid nanostructures demonstrated the highest hardness compared to pure nanotubes. Maximum hardness (52.7 GPa) was obtained for MWCNT/rGO topology. Regularity of an increase in electrical conductivity of nanostructures after laser irradiation has been established for films made of all nanomaterials. Hybrid structures of nanotubes and graphene sheets have the highest electrical conductivity compared to networks of pure nanotubes. Maximum electrical conductivity was obtained for MWCNT/rGO hybrid structure (~22.6 kS/m). Networks of nanotubes and CNT/rGO hybrids can be used to form strong electrically conductive interconnections in nanoelectronics, as well as to create components for flexible electronics and bioelectronics, including intelligent wearable devices (IWDs).

scholarly journals Multi-material braids for multifunctional laminates: conductive through-thickness reinforcement

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Caroline O’Keeffe ◽  
Laura Rhian Pickard ◽  
Juan Cao ◽  
Giuliano Allegri ◽  
Ivana K. Partridge ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Carbon Fibre ◽  
Electromagnetic Interference ◽  
Design Tool ◽  
Electrically Conductive ◽  
Current Collection ◽  
Wide Range ◽  
Predictive Design ◽  
The Right ◽  
Metal Wires

AbstractConventional carbon fibre laminates are known to be moderately electrically conductive in-plane, but have a poor through-thickness conductivity. This poses a problem for functionality aspects that are of increasing importance to industry, such as sensing, current collection, inductive/resistive heating, electromagnetic interference (EMI) shielding, etc. This restriction is of course more pronounced for non-conductive composite reinforcements such as glass, organic or natural fibres. Among various solutions to boost through-thickness electrical conductivity, tufting with hybrid micro-braided metal-carbon fibre yarns is one of the most promising. As a well-characterised method of through thickness reinforcement, tufting is easily implementable in a manufacturing environment. The hybridisation of materials in the braid promotes the resilience and integrity of yarns, while integrating metal wires opens up a wide range of multifunctional applications. Many configurations can be produced by varying braid patterns and the constituting yarns/wires. A predictive design tool is therefore necessary to select the right material configuration for the desired functional and structural performance. This paper suggests a fast and robust method for generating finite-element models of the braids, validates the prediction of micro-architecture and electrical conductivity, and demonstrates successful manufacturing of composites enhanced with braided tufts.

Titanomagnetites and ilmenites from the Early Cenozoic basalts and limburgites of the Northern Tien Shan

2011 ◽  
Vol 47 (6) ◽  
pp. 475-487 ◽  
Author(s):  
A. F. Grachev ◽  
D. M. Pechersky ◽  
V. A. Tsel’movich
Keyword(s):  
Tien Shan ◽  
Early Cenozoic ◽  
Northern Tien Shan
Sign in / Sign up

Export Citation Format

Share Document