Relationships between the kinematics of the top of a layer and the state of stress within it due to block motion at its base-connections with interpretation of recent movements

The equilibrium of an infinite linearly viscous layer overlying a rigid basement which is separated into blocks by a narrow plane slit is considered. The state of stress in the layer is caused by slow translational motions of the basement blocks. This spatial problem is shown to separate into problems of plane and anti-plane strain; their solutions are constructed in analytic form. The theoretical study was accompanied by modelling experiments. The results are applied to a kinematic interpretation of recent movements in sediments.     

Minerals of zirconolite group from fenitized xenoliths in nepheline syenites of Khibiny and Lovozero plutons,Kola Peninsula

Zirconolite, its Ce-, Nd-, and Y-analogs, and laachite, another member of the zirconolite group, are typomorphic minerals of the fenitized xenoliths in nepheline syenite and foidolite of the Khibiny–Lovozero Complex, Kola Peninsula, Russia. All these minerals are formed at the late stage of fenitization as products of ilmentie alteration under the effect of Zr-bearing fluids. The diversity of these minerals is caused by the chemical substitutions of Na and Ca for REE, Th, and U compensated by substitution of Ti and Zr for Nb, Fe and Ta, as well as by the redistribution of REE between varieties enriched in Ti (HREE) or Nb (LREE). The results obtained can be used in the synthesis of Synroc-type titanate ceramics assigned for the immobilization of actinides.     

Power spectra of thermal tidal and planetary waves in the near-Earth atmosphere and in the ionospheric D region at Kamchatka

Spectral analysis of the diurnal variations in the quasi-static electric field in the near-Earth atmosphere and VLF atmospheric radio noise at a frequency of 5.3 kHz, simultaneously observed in September–October 1999 at Paratunka observatory of the Institute of Cosmophysical Research and Radiowave Propagation, has been performed. The variations in the intensities of the spectral power density and the period durations of the variations in the T ～ 8–24 h band and higher as functions of geomagnetic and seismic activities have been studied.     

Hydrological processes at an Arctic river mouth: Case study of the Colville River, Alaska, USA

Data on the Colville River mouth (Alaska, USA) are used to discuss the regularities in hydrological processes taking place in river mouth areas, functioning under extreme arctic conditions. Seasons and periods are recognized in the annual cycle of the Colville river mouth hydrologic regime. A thick ice cover commonly forms in winter in the river, its delta distributaries, and the offshore zone. Water salinity in under-ice water in the distributaries and near-delta river reach appreciably increases in late winter. The spring flood is very short; in this period, snowmelt water propagates toward the ocean first over ice and next under it. A wedge of freshened waters forms in the nearshore zone above fast ice. River runoff abruptly drops in the summer-autumn low-water period. The morphological processes in the distributaries and some ecological conditions in the delta are also discussed.     

Variations of Trends in Delta Development under the Effect of External Natural and Anthropogenic Factors: Case Study of the Modern Huang He Mouth

The paper considers the major geographic features of the modern Huang He delta, which ranks among the most rapidly varying in the world. The structure of the hydrographic network and the combination of the natural and anthropogenic geosystems of the delta are characterized. The major external riverine and marine, as well as local anthropogenic factors that have affected the development of the Huang He delta in the recent half century are identified. The regularities of the jump-like development of the Huang He delta in the XIX–early XXI centuries are considered. Special attention is paid to the development of the delta after the artificial redistribution of flow in its boundaries in 1996. Satellite images and methods of their interpretation improved by the authors were used. The trends in Huang He delta development are shown to have changed since the last quarter of the XX century under the effect of an abrupt decrease in river sediment load and the growing impact of marine factors. The active progradation of the delta into the sea slowed down significantly, accompanied by erosion and retreat in many segments of its coastline. Huang He delta was used to establish the conditions of changes in the development trends of other deltas under the effect of changes in the climate and economic activity.     

Seismicity of the North of the Russian Plate: Relocation of Recent Earthquakese

The hypocenters of the earthquakes recorded in the north of the Russian Plate from 1982 to 2013 are relocated. The relocation of the hypocenters is based on the common velocity section, common methodology, and the entire set of the initial data and bulletins available from the Russian and foreign seismic stations. The efficiency of the algorithm for calculating the hypocentral parameters and the velocity section is demonstrated by the example of two nonmilitary nuclear explosions in July 18, 1985 and September 6, 1988 in the northern part of the European Russia. For the first time, two earthquakes of July 19, 1982 and October 7, 2012, which have not been previously reported in the catalogs for the north of the Russian plate, are included in the seismic catalog.     

Natural and anthropogenic long-term variations of water runoff and suspended sediment load in the Huanghe river

The hydrographic, climate, hydrological, and landscape features of the Huanghe R. Basin are considered. Water runoff and suspended sediment load in the Huanghe R. are shown to have dropped significantly in 1950–2009 under the effect of regional climate changes and economic activity in the basin. Water balance method and the concept of flow transport competency were used to assess the contribution of natural and anthropogenic factors (decline in precipitation, water withdrawal for economic needs, and the effect of reservoirs) to the decrease in river water runoff and suspended sediment load.     

Regularities in the Spasmodic Development of Deltas

Water Resources - Regularities of spasmodic delta formation, a rare type of the process, accompanied by breakthroughs and radical transformations of delta hydrographic network, are discussed. The...     

A New Approach to Studying Delta Formation

Water Resources - The article examines delta formation processes and suggests a new approach to their study. In the paper, delta formation is divided into its active and passive component. The...     

Batagayite,CaZn2(Zn,Cu)6(PO4)4(PO3OH)3·12H2O,a new phosphate mineral from Këster tin deposit (Yakutia,Russia): occurrence and crystal structure

Mineralogy and Petrology - Batagayite, CaZn2(Zn,Cu)6(PO4)4(PO3OH)3·12H2O, is a new secondary phosphate mineral from the Këster deposit, Arga-Ynnykh-Khai massif, NE Yakutia, Russia. It is...