We present a model of the propagation of refracted seismic waves in planar (horizontal or dipping) layered structures in which we quantify the errors from various sources. The model, called the (mixed) variance component model, separates the errors originating on the surface from those due to inhomogeneities of subsurface layers. The model starts with the assumption of homogeneous (constant-vel...

This article demonstrates the capabilities and integrity of environmental geological geophysical techniques for planning suitability extension Helwan city construction engineering purposes. The topographical mapping were utilized as well (seismic refraction, ground penetrating radar (GPR), resistivity soundings) optimal land-use planning. seismic refraction profiles conducted to evaluate geotec...

this paper is devoted to compiling a site geology map for town of amiriyeh, from seismic macro-zonation point of view using geophysical methods of shallow seismic, down-hole seismic and resistivity surveys. in this map site geology has been classified based on shear wave velocity, according to the criteria for site geology classification offered in the iranian code of practice for seismic resis...

Aims. We suggest an explanation for the high-frequency power excess surrounding active regions known as seismic halos. Methods. We use numerical simulations of magneto-acoustic wave propagation in magnetostatic sunspot model. Results. We propose that seismic halos can be caused by the additional energy injected by high-frequency fast mode waves refracted in the higher atmosphere due to the rapi...

PURPOSE To conduct a clinical validation of a virtual reality-based experimental system that is able to assess the spherical subjective refraction simplifying the methodology of ocular refraction. METHODS For the agreement assessment, spherical refraction measurements were obtained from 104 eyes of 52 subjects using three different methods: subjectively with the experimental prototype (Subj.E...

Shallow seismic methods have matured noticeably over the two decades since the first SAGEEP was held in 1988. At that time, the world’s scientific literature contained no more than a dozen refereed papers on shallow (less then 30 meters deep) reflection, but now there are hundreds of such examples. Analysis of surface waves was done with two-channel seismic systems in the 1980’s, whereas seismo...

Introduction: Several experiments performed by the astronauts on the Moon (e.g., the Apollo Lunar Surface Experiments Package, ASLEP), and proposed experiments as ground-prep for the return of humans to the Moon (RPLP-2/LPRP-2) involve the use of seismic (acoustic) energy for exploration. These seismic signals can be used for a wide array of purposes, from imaging the Lunar interior to detectin...