Anomalous Seismo-Electromagnetic Emission Related with Seismic Waves
This paper reports the rare high intensity electromagnetic pulses associated with earthquakes, with different to atmospherics spectrum signature. On the base of actual data records, the cases of generation of anomalous seismo-electromagnetic emission founded. These natural sub-millisecond electromagnetic pulses have been associated with passage of seismic waves through the place of electromagnetic field observations. The waveform, spectrum and time characteristics of sub-millisecond electromagnetic pulses have been described. The deeper the source the lower frequencies can be observed in the spectrum on the surface.
Modeling and analyzing of seismo-electromagnetics disturbance on crust of earth using FDTD method
In this paper, finite-difference time-domain (FDTD) method is applied for modeling and analyzing seismo-electromagnetics disturbance on the crust of earth. The proposed method is developed by modeling geographical map of the frontier between Sumatra island and Java island in 3D object based on a cylindrical coordinate system. To truncate the object simulation, uniaxial perfectly matched layer (UPML) boundary conditions are implemented. The amplitude variation of observed very low frequency (VLF) wave and propagation time between the disturbance and observation point are discussed. The result shows that the addition pulse influences the amplitude of observed sinusoidal VLF wave instead of its frequency. The propagation time of disturbance pulse is also influenced by the distance and the permittivity of the propagation medium.
Facies and microfacies of slope deposits
Abstract This paper reviews the facies and microfacies of the main types of slope deposits. Lamination and sorting, when preserved, are good evidence for overland flow. Features due to deformation (folds, boudins, coatings and tails due to the rotation of clasts) are associated with the early stages of deformation in earth slides. Other mass-movements such as debris flows, rock avalanches, earth flows, and to a certain extent, dry grain flows may be characterised by similar microscopic facies, typically a poorly sorted, porphyric material. Porosity gives evidence for both liquefaction (debris flows) and frost-induced mass-movement (solifluction). However, this criterion is thought to be irrelevant for fossil deposits owing to the rapidity and scale of post-depositional changes (wetting and drying, freezing and thawing, bioturbation). At present, only a detailed analysis of both the macro- and micromorphological characteristics of the deposits allows an accurate identification of past slope dynamics.