Nature of the macroseismic paradox of the deep-focus earthquake in the Sea of Okhotsk on May 24, 2013 (<Emphasis Type="Italic">M</Emphasis> <Subscript> <Emphasis Type="Italic">w</Emphasis> </Subscript> = 8.3)

We analyzed macroseismic data and considered the effect of extremely long range propagation of sensible shocks during the deep-focus earthquake in the Sea of Okhotsk on May 24, 2013 (M_w = 8.3). In order to explain this effect, we formulated and qualitatively solved the problem of superposition of P-waves over the radial mode ₀S₀ of the natural oscillations of the Earth during this earthquake. Our results confirmed the possibility of such an interpretation of the observed macroseismic effect and also allowed us to explain the fact of anomalously low decay of seismic disturbances with distance.     

Estimation of parameters of the flows forming sediment waves on the western slope of the middle caspian sea

By means of mathematical modeling, the parameters of flows forming sedimentary waves on the western slope of the Derbent basin were estimated. The height of these flows depends on the slope steepness and varies from 25 to 170 m to reach its maximum values at gentler slope areas. However, the flow rate is independent of the slope steepness and depends only on the concentration of sediment matter supplied by the flow. At the upper part of the slope (the flow starting), the rate amounts to 0.4–1.4 m/s, being almost halved at the depths where the sedimentary waves are damped. The present rates of near-bottom currents show pronounced seasonal differences, and their values are close to flow rates obtained by numerical modeling.     

A Generalized Model of Filtration in a Fractured-Porous Medium with Low-Permeable Inclusions and Its Possible Applications

Izvestiya, Physics of the Solid Earth - Abstract—This work generalizes the classical mathematical model of fluid and gas filtration in a fractured-porous medium. It results in a generalized...     

Theory of Filtration in a Double Porosity Medium

Doklady Earth Sciences - This paper defines a generalized mathematical model of filtration in a double porosity medium, taking into account recent ideas on liquid and gas flow in rocks with an...     

The origin and age of the Alpha-Mendeleev and Lomonosov ridges in the Amerasia Basin

The results of the bathymetry simulation indicate the emplacement of the Mesozoic Arctic plume into the lithosphere of the Alpha-Mendeleev and Lomonosov ridges. The study also presents a model of the thermal subsidence to the asthenosphere. The calculated coefficients are compared with those obtained for the Greenland-Iceland and Iceland-Faeroe ridges, which were formed in response to hotspot activity. It was shown that the coefficients of the thermal subsidence in the central part of the Alpha-Mendeleev and Lomonosov Ridges are similar to those calculated for the Greenland-Iceland and Iceland-Faeroe ridges. This indicates the thermal regime of the subsidence of the Alpha-Mendeleev and Lomonosov ridges since the Early Miocene and the increased influence of the Arctic plume on the ridge genesis. The ridges are interpreted to have formed over a broad geological timeframe, from the late Cretaceous to the Cenozoic. A geothermal method, which is highly informative in terms of the age of the lithosphere, provides better constraints on the timing of ridge formation. The age estimates for the Alpha-Mendeleev (97–79 Ma) and Lomonosov ridges (69–57 Ma) derived from the geothermal data allowed us to draw a convincing conclusion about the genesis of these ridges.     

Expected geological and geomorphological risks along the Northern Sea Route

Degradation of the underwater multiyear permafrost rocks (UMPR) together with intensification of thermal abrasion processes in the coasts are global risks on a planetary scale. Changes in the physical properties of sediments can occur after degradation of the UMPR and can lead to unpredictable consequences especially in the regions of technical development. Drifting ice bottom exaration (ice plucking of bottom sediments), which is increasing based on the data of recent expeditions, is no less dangerous. These processes are hazardous for practically all types of activity.     

Genesis of Shatsky and Hess oceanic rises in the pacific ocean as deduced from geologic-geophysical data and numerical modeling

The geologic structure and distribution of geophysical fields in the area of the Shatsky and Hess rises are considered. The ages of the Shatsky and Hess rises estimated at ～140 and ～100 Ma, respectively, from heat-flow parameters are consistent with the ages determined from magnetic measurements. The calculated thickness of the lithosphere beneath the rises (80–90 km) is close to that of the adjacent plates of the oceanic framework. This indicates that the rises were formed near the spreading axis. It is suggested that the rises evolved as autonomous structural features and their evolution followed the crystallization model of the oceanic-bottom formation. The tectonic analysis of the North Pacific has been carried out, and a geodynamic model of the growth of the Shatsky and Hess rises 140–83.5 Ma ago has been proposed. According to this model, the rises originated at the triple junction. This result is supported by the parameters of heat flow. The geothermal and geodynamic data and results of numerical modeling suggest that the origin of the Shatsky and Hess rises is related to plume tectonics.