Autonomous Instrumentation for Measuring Electromagnetic Radiation from Rocks in Mine Conditions—A Functional Analysis

This paper analyses the function of an innovative integrated receiver for the measurement of electromagnetic field emissions. The autonomous receiver measures and registers the elevated emission levels of both components of the EM field originating from rocks subjected to increased mechanical stress. The receiver’s sensitivity of 60 µV/m, its dynamic range of 98 dB, and its impulse response of 0.23 V/µs were determined in laboratory conditions. Real EM field signals from hard coal samples subjected to crushing force were recorded using an autonomous receiver. The observed and recorded results confirm that the receiver operates in the full range of amplitudes of the EM field signal emitted from the rock. The results determine the band of characteristic signals for EM field emission from hard coal. The system created on the basis of autonomous EM receivers can support the existing seismic safety systems in real mine conditions by predicting the possibility of mine collapse hazards.

Combined Study of a Significant Mine Collapse Based on Seismological and Geodetic Data—29 January 2019, Rudna Mine, Poland

On 29 January 2019, the collapse of a mine roof resulted in a significant surface deformation and generated a tremor with a magnitude of 4.6 in Rudna Mine, Poland. This study combines the seismological and geodetic monitoring of the event. Data from local and regional seismological networks were used to estimate the mechanism of the source and the ground motion caused by the earthquake. Global Navigation Satellite System data, collected at 10 Hz, and processed as a long-term time-series of daily coordinates solutions and short-term high frequency oscillations, are in good agreement with the seismological outputs, having detected several more tremors. The range and dynamics of the deformed surface area were monitored using satellite radar techniques for slow and fast motion detection. The radar data revealed that a 2-km2 area was affected in the six days after the collapse and that there was an increase in the post-event rate of subsidence.

Measurement of Electromagnetic Field Component Emissions as a Precursor of Emerging Hazard in Coal Mines

The article presents the results of research concerning electromagnetic (EM) field emitted by rocks during the process of their destruction. The paper describes a measuring stand designed for subjecting rock samples to axial crushing. During the destruction of rock samples, both components of the electromagnetic field emitted by the rock were recorded. The paper presents the results of research on hard coal samples, presenting the obtained time domain waveforms and frequency spectrum of the emitted EM field components. Further potential uses of tests concerned with EM emitted by rocks are determined. Applications registering EM field in mine environments may provide an early mine collapse warnings.

Resources and adaptation following involuntary resettlement in the Bytom-Karb community

Studies show that involuntary displacement often creates various threats for the community and individuals. To reduce these risks, Environmental and Social Impact Assessment, Health Impact Assessment, and Social Assessment are recommended. Whereas assessments focus mostly on the community level and studies describe cases of large population displacements, there is a lack of empirical evidence about how individuals cope with involuntary displacement and what factors contribute or hinder their successful adaptation in the target location. This study uses semi-structured interviews with 21 people about their experience of resettlement due to a mine collapse in Bytom, Poland, that led to involuntary displacement of 560 people. Data was analyzed according to the constructivist grounded theory principles. Results show that this case illustrates a mixture of post-disaster and development-induced displacement. Various factors and resources that affected coping strategies were analyzed, including: material and legal status, health and age, communication skills, and relocation experience. Our findings suggest that, when circumstances allow, an individual resources assessment should also be conducted to counteract impoverishment and further marginalization of the disprivileged and vulnerable individuals.