scholarly journals HYDROGEOCHEMICAL EARTHQUAKE PRECURSORS (ON THE EXAMPLE OF AREAS OF THE KAMCHATKA PENINSULA, RUSSIA, AND THE REPUBLIC OF UZBEKISTAN)

2020 ◽  
Vol 4(48) ◽  
pp. 5-20
Author(s):  
G.N. Kopylova ◽  
◽  
Sh.S. Yusupov ◽  
Yu.K. Serafimova ◽  
L.Yu. Shin ◽  
...  
Keyword(s):  
Seismic Waves ◽  
Seismic Energy ◽  
Kamchatka Peninsula ◽  
Test Site ◽  
Coseismic Deformation ◽  
Strong Earthquakes ◽  
Ground Shaking ◽  
Underground Waters ◽  
The Republic ◽  
Hydrogeochemical Precursors

Hydrogeochemical precursors of the earthquakes (HGCP) in changes of ion-salt and gas composition of underground waters from self-discharging wells and springs on the territory of Petropavlovsk-Kamchatsky test site, Kamchatka Peninsula, Russia and Tashkent test site, Republic of Uzbekistan are considered. There has been analyzed the connection of HGCP with parameters of earthquakes — with correlation between magnitudes and epicentral distances, as well as with values of specific density of seismic energy in the wave, intensity of ground shaking and other parameters of earthquake impact in the regions of observation. In Kamchatka wells HGCP were revealed before the earthquakes with Mw = 6.5 to 7.8 at epicentral distances de = 100 to 310 km at relatively narrow ranges of values of seismic energy density in the wave (0.1 to 0.3 J/m3), volumetric coseismic deformation of water-containing rocks (one to tens 10-9) and maximal velocities of seismic waves (3.5–7.7 cm/sec). HGCP took place in the zones with intensity of the earthquakes not less than 4 to 6 by MSK-64 scale and were confined to the intermediate zones of sources of future earthquakes. Duration of HGCP development and their appearance before the following earthquakes amount to 1 to 9 months, which allows using such precursors for prediction of time of strong earthquakes.

Ecological and Geochemical Features of the Underground Waters of the Semipalatinsk Test Site

2020 ◽  
Vol 24 (11) ◽  
pp. 30-35
Author(s):  
G.M. Yessilkanov ◽  
M.T. Dyussembayeva ◽  
L.P. Rikhvanov ◽  
N.Zh. Mukhamediyarov ◽  
A.Zh. Tashekova
Keyword(s):  
Water Quality ◽  
Test Site ◽  
World Health ◽  
Chemical Components ◽  
Underground Waters ◽  
Semipalatinsk Test Site ◽  
Quality Of Water ◽  
The Republic ◽  
Health Organization

The results of the study of ecological and geochemical features and assessment of the water quality of water sources located on the territory of the Semipalatinsk test site are presented. The studied waters are diverse in chemical composition: 14 % of the samples had hydrocarbonate, 69 % – sulfate, and 17 % – chloride types of waters. On the basis of the revealed features of the elemental composition of the underground waters of the Semipalatinsk test site, decreasing series of excess of the average concentrations of elements in water in relation to the composition of waters of the zones of hypergenesis and continental salinization were constructed: U14 > Mo8 > Sr8 > V3 (hypergenesis zone), U5 > Mo3 > Sr3 > V2 (zone of continental salinization). For the groundwater of the Semipalatinsk test site, specific elements were identified, such as U, Mo, Sr and V. The water quality was assessed for the studied chemical components based on comparison with the standards of the Republic of Kazakhstan and the World Health Organization (SaNPiN No. 209, WHO 2011).

scholarly journals Preseismic Groundwater Ion Content Variations: Observational Data in Flowing Wells of the Kamchatka Peninsula and Conceptual Model

Minerals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 731
Author(s):  
Galina Kopylova ◽  
Svetlana Boldina
Keyword(s):  
Chemical Composition ◽  
Observational Data ◽  
Water Movement ◽  
Water Pressure ◽  
Kamchatka Peninsula ◽  
Test Site ◽  
Ion Content ◽  
Strong Earthquakes ◽  
Hydrodynamic Parameters ◽  
Mixed Water

Repeated manifestations of hydrogeochemical anomalies in groundwater ion content variations before local strong earthquakes were recorded in three flowing wells of the Petropavlovsk-Kamchatsky test site. A model of changes in chemical composition of groundwater is considered using observational data and modeling of two waters mixing with contrasting composition in a zone of increased permeability in aquifer. Hydrodynamic parameters of the model—relaxation time of water pressure impulses and the time of mixed water movement in aquifer and wellbore—can vary from days to hundreds of days in individual wells. These parameters determine the duration and morphological features of anomaly in mixed water from a well. Using observational data from self-flowing well M-1, an assessment was made of chemical composition and mineralization of two mixing waters and their ratio in mixed water under background conditions and during the preparation of earthquake on 2 March 1992, Mw = 6.9.

scholarly journals The Influence of Surface Topography on the Weak Ground Shaking in Kathmandu Valley during the 2015 Gorkha Earthquake, Nepal

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 678
Author(s):  
Mark van der Meijde ◽  
Md Ashrafuzzaman ◽  
Norman Kerle ◽  
Saad Khan ◽  
Harald van der Werff
Keyword(s):  
Numerical Simulations ◽  
Surface Topography ◽  
Seismic Energy ◽  
Spectral Element ◽  
Kathmandu Valley ◽  
Ground Displacement ◽  
Gorkha Earthquake ◽  
Ground Shaking ◽  
Earthquake Scenarios ◽  
2015 Gorkha Earthquake

It remains elusive why there was only weak and limited ground shaking in Kathmandu valley during the 25 April 2015 Mw 7.8 Gorkha, Nepal, earthquake. Our spectral element numerical simulations show that, during this earthquake, surface topography restricted the propagation of seismic energy into the valley. The mountains diverted the incoming seismic wave mostly to the eastern and western margins of the valley. As a result, we find de-amplification of peak ground displacement in most of the valley interior. Modeling of alternative earthquake scenarios of the same magnitude occurring at different locations shows that these will affect the Kathmandu valley much more strongly, up to 2–3 times more, than the 2015 Gorkha earthquake did. This indicates that surface topography contributed to the reduced seismic shaking for this specific earthquake and lessened the earthquake impact within the valley.

Comparison of seismic waves generated by different types of source

1963 ◽  
Vol 53 (5) ◽  
pp. 965-978 ◽  
Author(s):  
David E. Willis
Keyword(s):  
Seismic Waves ◽  
Nuclear Explosion ◽  
Test Site ◽  
Frequency Content ◽  
Nevada Test Site ◽  
Different Types ◽  
The Waves ◽  
Source Duration ◽  
Lower Frequencies

Abstract A comparison of the seismic waves generated by a nuclear explosion and an earthquake is discussed. The epicenter of the earthquake was located within the Nevada Test Site. Both events were recorded at the same station with the same type of equipment. The earthquake waves contained slightly lower frequency than the waves generated by the nuclear shot. The early P phases of the shot had larger amplitudes while the phases after Pg for the earthquake were larger. Seismic waves from collapses were generally found to be composed of lower frequencies than the waves from the original shot. Aftershocks of the Hebgen Lake earthquake were found to generate seismic waves whose frequency content was related to the magnitude of the aftershock. Spectral differences in quarry shot recordings that correlate with source duration times are also discussed.

scholarly journals Global earthquakes in the 2020 second half according to the GS RAS

2021 ◽  
Vol 3 (1) ◽  
pp. 7-26
Author(s):  
Yuri Vinogradov ◽  
Mariya Ryzhikova ◽  
Natalia Petrov ◽  
Svetlana Poygina ◽  
Marina Kolomiets
Keyword(s):  
Seismic Energy ◽  
Aegean Sea ◽  
Focal Mechanisms ◽  
Intraplate Earthquake ◽  
Strong Earthquakes ◽  
Tatar Strait ◽  
The Earth ◽  
Deformation Processes ◽  
The Russian Federation ◽  
Deep Focus

The data on the seismicity of the Earth in the second half of 2020 at the level of strong earthquakes with magnitudes mb≥6.0 are given according to the data of the Alert Service of the Geophysical Survey RAS. The review also includes information on 54 tangible earthquakes in Russia and five earthquakes in adjacent territories that were felt in the settlements of the Russian Federation. Two of 67 strong earthquakes of the Earth with mb≥6.0 for the period under consideration were registered in the territory of Russia. For 15 strong earthquakes, the Alert Service published Information Messages within one or two days after their occurrence, for 14 earthquakes the information on focal mechanisms is provided. The strongest earthquake of the Earth with MS=7.9 occurred on July, 22 in the region of the Alaska Peninsula. The maximum human casualties and material damage during the study period were the result of the catastrophic intraplate earthquake with MS=6.8, which occurred on October, 30 in the Aegean Sea, near the Samos Island. As a result of the earthquake, 117 people died, 1054 were injured. The strongest earthquake on the territory of Russia was the deep-focus one with mb=6.4, which took place on November, 30 in the Tatar Strait, separating Sakhalin Island from continental Eurasia. The crustal Bystrinsk earthquake on September, 21 with MS=5.2, which occurred in the area of Lake Baikal, was felt with a maximum intensity I=6–7 on the territory of Russia. Comparative analysis of the rate of seismic energy released in the Globe in 2010-2020 showed that its value in the second half of 2020, as well as for 2019-2020 on average, is one of the lowest for the eleven-year period and indicates a seismic calm, which should be replaced by a period of intensification of global seismic and deformation processes

Methodological Foundation and Assessment of Artesian Water Treatment Technology in the Republic of the Union Of Myanmar

2021 ◽  
Vol 25 (8) ◽  
pp. 34-39
Author(s):  
Maung Lin Maung ◽  
Htet Aung ◽  
Saw Thurain ◽  
D.V. Parusov ◽  
G.G. Kagramanov ◽  
...  
Keyword(s):  
Potable Water ◽  
Water Production ◽  
Treatment Technology ◽  
Underground Waters ◽  
Methodological Foundation ◽  
Technical And Economic Analysis ◽  
Drinking Water Production ◽  
The Republic ◽  
High Degree ◽  
Iron And Manganese

The analysis of the compositions of artesian waters from the Republic of the Union of Myanmar as a source of potable water production is carried out. The underground waters are characterized by high degree of hardness and content of iron and manganese. Total dissolved solids (TDS) concentration corresponding thus to the class of brackish water. Three potential approaches to the development of drinking water production technology are proposed. Technical and economic analysis of the specific operating costs for potable water from artesian resources of Republic of the Union of Myanmar was carried out and the optimal technological schemes of treatment plants were determined.

Fragility curves for toppling of railroad locomotives

2020 ◽  
Vol 36 (4) ◽  
pp. 1623-1644
Author(s):  
Bruce F Maison
Keyword(s):  
United States ◽  
Size Effect ◽  
Case Studies ◽  
Fragility Curves ◽  
Western United States ◽  
Passenger Cars ◽  
Strong Earthquakes ◽  
Ground Shaking ◽  
Seismic Regions

Three locomotives that overturned (toppled) during strong earthquakes (>6.5M) are used as computer analytical case studies. The locomotives were at rest or traveling very slowly at the time of the earthquakes. Fragility curves are presented relating ground shaking intensity to likelihood of toppling. Supplemental studies determine the influence of various parameters, including track gauge, damping, sway-roll period, and size effect. The shaking intensities necessary for standard gauge (56.5 in) locomotives to topple are much greater than the median intensities of 2475-year earthquakes representative of those in high seismic regions of the western United States. A general conclusion is that standard gauge locomotives at rest are not susceptible to toppling in such earthquakes (≪50% chance). This can be expected to be the case as well for freight and passenger cars having sizes and slenderness similar to the case study locomotives. The study also provides insights about the toppling fragility of other large unanchored objects having similar proportions.

scholarly journals Geological and Structural Control on Localized Ground Effects within the Heunghae Basin during the Pohang Earthquake (MW 5.4, 15th November 2017), South Korea

Geosciences ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 173 ◽  
Author(s):  
Sambit Naik ◽  
Young-Seog Kim ◽  
Taehyung Kim ◽  
Jeong Su-Ho
Keyword(s):  
South Korea ◽  
Structural Control ◽  
Seismic Waves ◽  
Tectonic Setting ◽  
Lateral Spreading ◽  
Soil Liquefaction ◽  
Ground Shaking ◽  
Potential Mapping ◽  
Sand Boils ◽  
Ground Effects

On 15th November 2017, the Pohang earthquake (Mw 5.4) had strong ground shaking that caused severe liquefaction and lateral spreading across the Heunghae Basin, around Pohang city, South Korea. Such liquefaction is a rare phenomenon during small or moderate earthquakes (MW < 5.5). There are only a few examples around the globe, but more so in the Korean Peninsula. In this paper, we present the results of a systematic survey of the secondary ground effects—i.e., soil liquefaction and ground cracks—developed during the earthquake. Most of the liquefaction sites are clustered near the epicenter and close to the Heunghae fault. Based on the geology, tectonic setting, distribution, and clustering of the sand boils along the southern part of the Heunghae Basin, we propose a geological model, suggesting that the Heunghae fault may have acted as a barrier to the propagation of seismic waves. Other factors like the mountain basin effect and/or amplification of seismic waves by a blind thrust fault could play an important role. Liquefaction phenomenon associated with the 2017 Pohang earthquake emphasizes that there is an urgent need of liquefaction potential mapping for the Pohang city and other areas with a similar geological setting. In areas underlain by extensive unconsolidated basin fill sediments—where the records of past earthquakes are exiguous or indistinct and there is poor implementation of building codes—future earthquakes of similar or larger magnitude as the Pohang earthquake are likely to occur again. Therefore, this represents a hazard that may cause significant societal and economic threats in the future.

scholarly journals SEISMIC BEHAVIOR OF STEEL MONORAIL BRIDGES UNDER TRAIN LOAD DURING STRONG EARTHQUAKES

2013 ◽  
Vol 07 (02) ◽  
pp. 1350006 ◽  
Author(s):  
C. W. KIM ◽  
M. KAWATANI ◽  
T. KANBARA ◽  
N. NISHIMURA
Keyword(s):  
Seismic Behavior ◽  
Analytical Study ◽  
Seismic Energy ◽  
Dynamic Responses ◽  
Additional Mass ◽  
Plastic Deformations ◽  
Strong Earthquakes ◽  
Lateral Bracing ◽  
Bracing System ◽  
Conventional Type

This paper investigated dynamic responses of steel monorail bridges incorporating train-bridge interaction under strong earthquakes. Two types of steel monorail bridges were considered in the study: a conventional type with steel track-girder; an advanced type with composite track-girder and simplified lateral bracing system. During strong earthquakes, monorail train was assumed standing on the track-girder of monorail bridges. Observations through the analytical study showed that considering the monorail train as additional mass rather than a dynamic system in numerical modeling overestimated effect of the train load on seismic performance of monorail bridges. Earlier plastic deformations at the end bracing of the girder system absorbed seismic energy and reduced the stress at the pier base.

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