On Classification of the Earth's Crust Areas by the Level of Geodynamic Threat

It is accepted as a well-known fact that a similar anthropogenic impact on the Earth's crust in different places causes dissimilar response. Seismic zoning maps are not designed to predict such geodynamic hazards as rock bursts, induced earthquakes, reactivation of tectonic faults, etc., and require careful adjustment in places of intense impact on the subsurface strata. In this regard, we consider the classification of the Earth's crust areas according to the degree of geodynamic hazard, i.e. its potential geodynamic response to anthropogenic intervention. This classification is based on the concept that there exists a critically stressed layer within the Earth’s crust. It is believed that such critically stressed layer within the Earth’s crust extends from the Earth's surface to a certain depth, which at each point depends on the nature of the interaction between crustal blocks of different hierarchical levels.From this perspective, anthropogenic impact, such as mining operations, represents a direct impact upon the critically stressed zone. The hypothesis is accepted that the thicker is the critical stressed rock layer, the stronger might be the response to anthropogenic intervention, as it has more accumulated energy. Four categorized of the geodynamic threat were found and mapped. To verify this classification, the manifestations of the geodynamic hazards were studied. The intensity of geodynamic hazard increases from the 1st area to the 4th area. The phenomenon of large induced seismic events with hypocenters at great depths is explained by the base of this idea and could be associated with anthropogenic impacts from the surface directly on the regional zone of the critical stressed rock massif. The approach can be used to assess the geodynamic consequences of human exposure to the Earth's crust.

Determination of Stresses in Incrementally Deposited Films From Wafer-Curvature Measurements

We report closed-form formulas to calculate the incremental-deposition stress, the elastic relaxation stress, and the residual stress in a finite-thickness film from a wafer-curvature measurement. The calculation shows how the incremental deposition of a new stressed layer to the film affects the amount of the film/wafer curvature and the stress state of the previously deposited layers. The formulas allow the incremental-deposition stress and the elastic relaxation to be correctly calculated from the slope of the measured curvature versus thickness for arbitrary thicknesses and biaxial moduli of the film and the substrate. Subtraction of the cumulative elastic relaxation from the incremental-deposition stress history results in the residual stress left in the film after the whole deposition process. The validities of the formulas are confirmed by curvature measurements of electrodeposited Ni films on substrates with different thicknesses.

The effect of distributed dislocations on bending of a rectangular beam with a preliminarily stressed layer under superposition of large strains

The formulation of problems on the equilibrium of a nonlinearly elastic solid with continuously distributed dislocations is proposed for the case of superposition of large strains. The numerical results showing the effect of distributed dislocations on the stress-strain state of the beam are presented.