A critical discussion of the electromagnetic radiation (EMR) method to determine stress orientations within the crust

Krumbholz, Michael; Bock, Michael; Burchardt, Steffi; Kelka, Ulrich; Vollbrecht, Axel

doi:10.5194/se-3-401-2012

Cited by 23 publications

(7 citation statements)

References 37 publications

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“…The measuring receivers have their own battery power supply. Described above measuring system is innovative compared with solutions presented in other papers [3], [5], [7], [9]. Connection of the underground receiver with the processing block by means of an optical fibre and equipped this probe with the independent non-disruptive battery supply (without a DC/DC isolated power converter or similar device), significantly reduces influence of electromagnetic disturbances.…”

Section: Landslide Activity Measuring Systemmentioning

confidence: 99%

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Measuring Electromagnetic Emissions from Active Landslides

Maniak

2015

JTIT

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The paper describes the mechanism of electromagnetic emission generation in active landslides and measuring techniques. Special attention is given to electromagnetic emission fields. The author proposes an original system for measuring both continuous and pulsed magnetic emission of landslides. For such measurements boreholes must be drilled in the landslide. It is essential that the tubing constituting the borehole’s lining be made of a material which does not attenuate magnetic fields. Besides its primary function, i.e. the registration of landslide magnetic field activity, the system can be used for the structural inhomogeneity of rock strata examination subjected to considerable stresses. The results of examinations of active and inactive landslide in Poland are presented. The post-extraction cave in the SMZ Jelsava Mine in Jelsava, Slovakia, is presented too.

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Section: Landslide Activity Measuring Systemmentioning

confidence: 99%

“…Number of pulses indicated intensity of landslide movement processes. Other interesting measurement equipment is a portable device called the Cerescope [9]. This magnetic field receiver, reveals maximum sensitivity at 12.8 kHz, counts number of pulses in the 100 ms period.…”

Section: Introductionmentioning

confidence: 99%

Measuring Electromagnetic Emissions from Active Landslides

Maniak

2015

JTIT

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“…Misra led pioneering efforts in the 1980s [4][5][6] to report the EMR emission signals in metallic materials during fracture. Several researchers since then have examined this phenomenon [7][8][9][10][11]. During plastic deformation of the uncoated and coated metal sheets, a secondary EMR signal emission phenomenon was discovered [12].…”

Section: Introductionmentioning

confidence: 99%

Influence of an Engineered Notch on the Electromagnetic Radiation Performance of NiTi Shape Memory Alloy

Anand,

Kumar,

Pandey

et al. 2024

Materials

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This work explores the influence of a pre-engineered notch on the electromagnetic radiation (EMR) parameters in NiTi shape memory alloy (SMA) during tensile tests. The test data showed that the EMR signal fluctuated between oscillatory and exponential, signifying that the specimen’s viscosity damping coefficient changes during strain hardening. The EMR parameters, maximum EMR amplitude, and average EMR energy release rate remained constant initially but rose sharply with the plastic zone radius with progressive loading. It was postulated that new Frank–Read sources permit dislocation multiplication and increase the number of edge dislocations participating in EMR emissions, leading to a rise in the value of EMR parameters. The study of the correlation between EMR emission parameters and the plastic zone radius before the crack tip is a vital crack growth monitoring tool. An analysis of the interrelationship of the EMR energy release rate at fracture with the elastic strain energy release rate would help develop an innovative approach to assess fracture toughness, a critical parameter for the design and safety of metals. The microstructural analysis of tensile fractures and the interrelation between deformation behaviours concerning the EMR parameters offers a novel and real-time approach to improve the extant understanding of the behaviour of metallic materials.

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“…Effective monitoring and early warning of coal and rock dynamic disasters is the key to disaster prevention and control. In the process of coal and rock fracture under load, the energy accumulated inside will partly be released in the form of electromagnetic energy [4][5][6], based on which, the electromagnetic radiation (EMR) method has been widely used in the field of coal and rock dynamic disaster prevention and control in coal mines [7][8][9].…”

Section: Introductionmentioning

confidence: 99%

Discrete characteristics of instantaneous frequency of EMR induced by coal and rock fracture

Lou

Jia

Wan

et al. 2023

Meas. Sci. Technol.

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To reveal the discrete characteristics of the instantaneous frequency of the electromagnetic radiation (EMR) waveform induced by coal and rock fracture, the uniaxial compression experiments for coal and rock samples were carried out, and the EMR signals with full waveform were acquainted and stored. The empirical wavelet transform (EWT) is used to filter and de-noise the EMR waveform, and then the short-time Fourier transform (STFT) is used to analyze the time-frequency characteristics of the waveform. The discrete characteristics of the instantaneous frequency with a larger amplitude and the relationship between the centroid frequencies and peak-to-peak values (Vpps) of the EMR waveforms are statistically analyzed. The results show that the centroid frequency of 0–100 kHz is negatively correlated with the Vpp, and the relationship between them shows a logarithm function relation. The instantaneous frequency of the EMR waveform of coal and rock fracture has significant discrete characteristics. In detail, for the rock sample, the instantaneous frequencies with relatively large amplitude are mainly 4.5 kHz, 19.5 kHz, 22.0 kHz, and 27.5 kHz; for the coal sample, the instantaneous frequencies are mainly 1.0 kHz, 4.5 kHz, 9.0 kHz, and 74.0 kHz. This discrete characteristic is determined by the natural properties and fracture characteristics of the sample. Compared with the homogeneous rock samples, the internal cracks of the coal samples are well developed and show strong anisotropy, resulting in the discrete characteristics of the instantaneous frequency being relatively weaker. The findings have certain guiding significance for optimizing the design of the EMR monitoring frequency band and improving the pertinence and accuracy of the monitoring and early warning for coal and rock dynamic disasters.

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A critical discussion of the electromagnetic radiation (EMR) method to determine stress orientations within the crust

Cited by 23 publications

References 37 publications

Measuring Electromagnetic Emissions from Active Landslides

Measuring Electromagnetic Emissions from Active Landslides

Influence of an Engineered Notch on the Electromagnetic Radiation Performance of NiTi Shape Memory Alloy

Discrete characteristics of instantaneous frequency of EMR induced by coal and rock fracture

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