scholarly journals Environmental impacts of earthquake hazards: Indian scenario

1998 ◽  
Vol 18 ◽  
Author(s):  
Pramendra Dev
Keyword(s):  
Large Earthquake ◽  
Earthquake Activity ◽  
Earthquake Hazards ◽  
Earthquake Insurance ◽  
Groundwater Levels ◽  
Seismicity Pattern ◽  
Environmental Consequences ◽  
Landuse Planning ◽  
Prediction And Control ◽  
Short Term Prediction

An overview of environmental consequences resulting due to earthquake phenomena in various parts of India, is presented. The prominent characteristics of major earthquake operations as well as the damages caused to environmental regime and human population are enumerated. The problems of earthquake prediction and control are also discussed. Prediction of hazardous earthquake activity can be made on the different criteria such as: seismicity pattern preceding large earthquake, recurrence intervals of earthquake events, dilatancy phenomena of high strain zone, changes in groundwater levels and composition and anomalous animal behaviour. However, precise technique for short term prediction is still to be evolved. Earthquake disasters can be reduced to some extent by adopting adequate remedial measures before, during and after the activity. It is opined that the environmental awareness should be exercised to educate people regarding the defensive operations to protect themselves from adverse effects of earthquakes. The appropriate steps such as schemes of landuse planning, regulation of structural design, and provisions of earthquake insurance programmes may be considered for implementation on priority.

scholarly journals Changes in the ultra-low frequency wave field during the precursor phase to the Sichuan earthquake: DEMETER observations

2013 ◽  
Vol 31 (9) ◽  
pp. 1597-1603 ◽  
Author(s):  
S. N. Walker ◽  
V. Kadirkamanathan ◽  
O. A. Pokhotelov
Keyword(s):  
Low Frequency ◽  
Large Earthquake ◽  
Short Term ◽  
Frequency Wave ◽  
Sichuan Earthquake ◽  
Ulf Wave ◽  
Precursor Phase ◽  
Demeter Satellite ◽  
Short Term Prediction ◽  
Atmospheric Gravity

Abstract. Electromagnetic phenomena observed in association with increases in seismic activity have been studied for several decades. These phenomena are generated during the precursory phases of an earthquake as well as during the main event. Their occurrence during the precursory phases may be used in short-term prediction of a large earthquake. In this paper, we examine ultra-low frequency (ULF) electric field data from the DEMETER satellite during the period leading up to the Sichuan earthquake. It is shown that there is an increase in ULF wave activity observed as DEMETER passes in the vicinity of the earthquake epicentre. This increase is most obvious at lower frequencies. Examination of the ULF spectra shows the possible occurrence of geomagnetic pearl pulsations, resulting from the passage of atmospheric gravity waves generated in the vicinity of the earthquake epicentre.

scholarly journals Neural Networks for Prediction and Control of Chaotic Fluidized Bed Hydrodynamics

Fractals ◽  
1997 ◽  
Vol 05 (03) ◽  
pp. 523-530 ◽  
Author(s):  
R. Bakker ◽  
R. J. de Korte ◽  
J. C. Schouten ◽  
C. M. Van Den Bleek ◽  
F. Takens
Keyword(s):  
Fluidized Bed ◽  
Prediction Error ◽  
Control Of Chaos ◽  
Short Term ◽  
Prediction And Control ◽  
Short Term Prediction ◽  
Capacitance Tomography ◽  
And Control ◽  
Dynamic Invariants ◽  
Tomography Data

A neural-network-based model that has learnt the chaotic hydrodynamics of a fluidized bed reactor is presented. The network is trained on measured electrical capacitance tomography data. A training algorithm is used that does not only minimize the short-term prediction error but also the information needed to synchronize the model with the real system. This forces the model to focus more on learning the longer term dynamics of the system, expressed in the average multi-step-ahead prediction error and dynamic invariants such as correlation entropy and dimension. The availability of the model is an important step towards control of chaos in gas-solid fluidized beds.

scholarly journals SafeNet: SwArm for Earthquake Perturbations Identification Using Deep Learning Networks

2021 ◽  
Vol 13 (24) ◽  
pp. 5033
Author(s):  
Pan Xiong ◽  
Dedalo Marchetti ◽  
Angelo De Santis ◽  
Xuemin Zhang ◽  
Xuhui Shen
Keyword(s):  
Deep Learning ◽  
European Space Agency ◽  
Window Size ◽  
Large Earthquake ◽  
Low Earth Orbit ◽  
Earthquake Activity ◽  
Learning Networks ◽  
Satellite Mission ◽  
Ionospheric Perturbations ◽  
Precursor Effects

Low Earth orbit satellites collect and study information on changes in the ionosphere, which contributes to the identification of earthquake precursors. Swarm, the European Space Agency three-satellite mission, has been launched to monitor the Earth geomagnetic field, and has successfully shown that in some cases it is able to observe many several ionospheric perturbations that occurred as a result of large earthquake activity. This paper proposes the SafeNet deep learning framework for detecting pre-earthquake ionospheric perturbations. We trained the proposed model using 9017 recent (2014–2020) independent earthquakes of magnitude 4.8 or greater, as well as the corresponding 7-year plasma and magnetic field data from the Swarm A satellite, and excellent performance has been achieved. In addition, the influence of different model inputs and spatial window sizes, earthquake magnitudes, and daytime or nighttime was explored. The results showed that for electromagnetic pre-earthquake data collected within a circular region of the epicenter and with a Dobrovolsky-defined radius and input window size of 70 consecutive data points, nighttime data provided the highest performance in discriminating pre-earthquake perturbations, yielding an F1 score of 0.846 and a Matthews correlation coefficient of 0.717. Moreover, SafeNet performed well in identifying pre-seismic ionospheric anomalies with increasing earthquake magnitude and unbalanced datasets. Hypotheses on the physical causes of earthquake-induced ionospheric perturbations are also provided. Our results suggest that the performance of pre-earthquake ionospheric perturbation identification can be significantly improved by utilizing SafeNet, which is capable of detecting precursor effects within electromagnetic satellite data.

scholarly journals GEOPHYSICAL INVESTIGATIONS OF A POTENTIAL LANDSLIDE AREA IN MAYOON, HUNZA DISTRICT, GILGIT-BALTISTAN, PAKISTAN

2021 ◽  
Vol 36 (3) ◽  
pp. 127-141
Author(s):  
Qasim ur Rehman ◽  
Waqas Ahmed ◽  
Muhammad Waseem ◽  
Sarfraz Khan ◽  
Asam Farid ◽  
...  
Keyword(s):  
Slip Rate ◽  
Bottom Layer ◽  
Earthquake Activity ◽  
Earthquake Hazards ◽  
Ground Acceleration ◽  
Non Invasive ◽  
Unconsolidated Material ◽  
Geophysical Investigations ◽  
Ground Penetrating ◽  
Gilgit Baltistan

The Mayoon landslide in the Hunza District is a slowly developed, non-catastrophic landslide that has gained its importance in the last few years after its rapid activation and fast slip rate. The area is characterized by high earthquake hazards (zone 3 with a peak ground acceleration value of 2.4–3.2 m/s2) by the Building Code of Pakistan due to frequent earth quakes. The past high earthquake activity in the area has displaced the foliated rocks towards the south and is responsible for opening the bedrock joints. The head and body of the landslide are covered by unconsolidated material and have fractures of varying lengths and widths. The non-invasive geophysical techniques, including Ground Penetrating Radar (GPR) and Electrical Resistivity Soundings (ERS), are deployed to evaluate the Mayoon landslide subsurface. The subsurface is interpreted into a two-layer model. Bright reflectors and highly variable resistivity characterize the top layer (Layer-1). This layer is associated with a loose, highly heterogeneous, fragmented material deposited under glacial settings over the existing bedrock. Hyperbolic reflections and intermediate resistivity characterize the bottom layer (Layer-2). This layer is associated with foliated metamorphic bedrock. The hyperbolic reflections show faults/fractures within the bedrock. The extension of these fractures/faults with depth is uncertain due to decay in the GPR signal with depth. The intermediate resistivity shows the bedrock is weathered and foliated. Reflections within Layer-1 have disrupted directly above the fractures/faults suggesting a possible movement. A bright reflection between the two layers highlights the presence of the debonded surface. Loose material within Layer-1 coupled with debonding possesses a significant hazard to generate a landslide under unfavourable conditions, such as an intense rainstorm or earthquake activity.

scholarly journals Complex rupture dynamics on an immature fault during the 2020 Mw 6.8 Elazığ earthquake, Turkey

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
František Gallovič ◽  
Jiří Zahradník ◽  
Vladimír Plicka ◽  
Efthimios Sokos ◽  
Christos Evangelidis ◽  
...  
Keyword(s):  
Stress Transfer ◽  
Strong Motion ◽  
Large Earthquake ◽  
Earthquake Hazard ◽  
Earthquake Hazards ◽  
Earthquake Physics ◽  
Rupture Dynamics ◽  
Earthquake Hazard Assessment ◽  
Modern Physics ◽  
Physical Laws

Abstract Physical laws governing friction on shallow faults in the Earth and spatial heterogeneity of parameters are critical to our understanding of earthquake physics and the assessment of earthquake hazards. Here we use a laboratory-derived fault-friction law and high-quality strong-motion seismic recordings of the 2020 Elazığ earthquake, Turkey, to reveal the complex rupture dynamics. We discover an initial Mw 5.8 rupture stage and explain how cascading behavior of the event, involving at least three episodes, each of M > 6, caused it to evolve into a large earthquake, contrarily to other M5+ events on this part of the East Anatolian Fault. Although the dynamic stress transfer during the rupture did not overcome the strength of the uppermost ~5 kilometers, surface ruptures during future earthquakes cannot be ruled out. We foresee that future, routine dynamic inversions will improve understanding of earthquake rupture parameters, an essential component of modern, physics-based earthquake hazard assessment.

Stress-forecasting: a viable alternative to earthquake prediction in a dynamic Earth

1998 ◽  
Vol 89 (2) ◽  
pp. 121-133 ◽  
Author(s):  
Stuart Crampin
Keyword(s):  
Earthquake Prediction ◽  
Crustal Deformation ◽  
Large Earthquake ◽  
Viable Alternative ◽  
Earthquake Hazards ◽  
Seismic Shear ◽  
Stress Changes ◽  
Wave Splitting ◽  
Self Organised Criticality ◽  
Large Earthquakes

AbstractSelf-organised criticality of the crust appears to make deterministic earthquake prediction of time, place and magnitude of individual large earthquakes inherently impossible. This closes one line of approach to mitigating earthquake hazards. This paper suggests that a viable alternative to earthquake prediction is monitoring the build-up of stress before a large earthquake can occur. A new understanding of rock deformation allows stress changes to be monitored with seismic shear-wave splitting (seismic birefringence). With a suitable monitoring installation, this would allow the stochastic proximity of impending earthquakes to be recognised so that earthquakes could be forecast in the sense of recognising that crustal deformation was preparing for a large earthquake. Such stress-forecasting is not prediction, but, in many circumstances, a possible forecast crescendo of increasing urgency is exactly what is needed to best mitigate hazard to life and property.

scholarly journals INFORMATION TECHNOLOGIES FOR MONITORING THE ENVIRONMENTAL CONSEQUENCES OF AMBER PRODUCTION IN UKRAINE

2018 ◽  
pp. 107-117
Author(s):  
H. Ya. Krasovskyi ◽  
V. O. Shumeiko ◽  
T. O. Klochko ◽  
N. I. Sementsova
Keyword(s):  
Remote Sensing ◽  
Information Technologies ◽  
Production Management ◽  
Ecological Impacts ◽  
Open Pit ◽  
Environmental Damage ◽  
Earth Remote Sensing ◽  
Geoinformation Systems ◽  
Groundwater Levels ◽  
Environmental Consequences

Among the environmental consequences of the illegal production of amber, the experts single out the degradation of zonal soils and underlying bed rocks, destruction of fertile humus and eluvial horizons of podzolic soils, root systems of trees, swamp formation, change in groundwater levels, destruction of forest resources, and change in the migration processes of the region’s fauna. The most serious ecological and economic problems are caused by the unauthorized production of amber in Rivne, Volyn and Zhytomyr oblasts, where the illegal production of amber is carried out by open-pit and hydromechanical methods. The main tasks set forth in the article are: to analyze the places and conditions of amber production, to define its influence on the environment components, to identify the objects of natural resources use by means of Earth remote sensing methods. The article deals with the development of modern information technology for identifying the places and consequences of amber production in the western regions of Polissia based on the methods of satellite environmental monitoring and tools of geoinformation systems. The production technologies and the manifestation of their ecological impacts are described. The environmental impact assessment of amber production is not possible without defining the potential operational risks, identifying the locations and extent of environmental damage. Due to local peculiarities of amber production management, it is rather difficult to fix the topographic and geodetic parameters of the manifestations of these effects, which complicates the planning of prevention and elimination measures. The methods of Earth remote sensing (ERS) from space and geoinformation systems (GIS) can define these parameters with high accuracy, reliability and efficiency, which will enable the efficient monitoring of the environmental components degradation.

scholarly journals Analysis of Changes in Seismicity Pattern for Probabilistic Seismic Hazard Analysis (PSHA) and Mitigation: Mapping Probability Difference before the Large Earthquake and Its Implementation in PSHA & Mitigation around Northern Sumatra

2020 ◽  
Author(s):  
Wahyu Triyoso ◽  
Tedi Yudistira ◽  
David P. Sahara
Keyword(s):  
Seismic Hazard ◽  
Hazard Analysis ◽  
Large Earthquake ◽  
Probabilistic Seismic Hazard Analysis ◽  
Seismic Hazard Analysis ◽  
Probabilistic Seismic Hazard ◽  
Ground Acceleration ◽  
Seismicity Rate ◽  
Seismicity Pattern ◽  
Major Earthquake

Abstract The probability difference before the occurrence of a large earthquake is mapped in the northern part of Sumatra, taking the range of Region Time Length (RTL) before a major earthquake (December 26, 2004) around 15 years. By normalizing the absolute value of probability difference between two periods of RTL and before RTL, the Seismic Quiescence Index (SQI) is then defined. Probability difference analysis is done by dividing observations of shallow earthquake periods into two periods based on the similarity gradient of the annual earthquake production, namely 1963-1990 and 1991-November 2004. The results showed that areas with relatively high SQI were consistent with the presence of major earthquake events after November 2004 to 2016 that are sorted by a radius of 300 km with the center point being the epicenter position of the December 2004 earthquake. The implementation of the SQI was then used for probabilistic seismic hazards study and analysis based on an integratedmodel that is derived based on the estimated of seismicity rate of around the subduction zone and active fault of Sumatra Fault Zone (SFZ) sources. The map of Probabilistic Seismic Hazard Analysis (PSHA) is then constructed based onPeak Ground Acceleration (PGA) estimated for a 10% Probability Exceedance (PE) level in 50 years. The results of this study may be very useful for earthquake mitigation and modeling efforts for PSHA going forward.

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