Investigation by backscatter radar of artificial irregularities produced in ionospheric plasma heating experiments

The artificial ionospheric turbulence occurs in the ionosphere illuminated by high power HF radio waves. There are a lot of irregularities stretched along the geomagnetic field in this region. The investigation of the artificially disturbed ionospheric region is based on the reception of back scattered signals (BSS) which permits the basic parameters of this region to be estimated and its inhomogeneous structure to be described.Experiments were carried out using ‘Sura’ heating facility in the frequency range of ? = 4.7–9 MHz (ordinary mode) with the effective radiated power P_eff = 50–70 MW beamed vertically upwards. The most important dynamic and statistical BSS characteristics (the built-up time, the relaxation and autocorrelation times, the BSS amplitude spatial correlation function and power spectra) were measured using probe waves in the frequency range of that made it possible to obtain the basic parameters of the artificial irregularities. The model representation of a disturbed region in a form of a periodic structure gives a possibity to evaluate the scale of the structure, the whole size of the disturbance and its power and to calculate the main BSS characteristics.     

A new type of noble metal mineralization in the Northern Caucasus

The weathering crust of the Beden ultrabasite massif (the basin of Big Laba River) is identified and studied. Anomalously high contents of noble metals (Au, Pt, Pd) are revealed in the basal horizon of the Jurassic part of the weathering crust. For this reason we suspect an existence of a belt of noble metal miner-alization in the Paleozoic ultrabasites in the Peredovoi Range of the Northern Caucasus.     

A New 190Pt-4He method of native platinum age determination

A new method of determining the age of native platinum based on alpha-radioactivity of one of its natural isotopes ¹⁹⁰Pt is proposed. Due to a special form of occurrence of radiogenic helium in the crystal lattice of native metals as a helium cluster-bubbles, the stability of ¹⁹⁰Pt-⁴He of the isotope system is extremely high in the natural environment. To check the efficiency of the proposed ¹⁹⁰Pt-⁴He method of isotope geochronology, six independent mineral aggregates of native platinum from chromite-bearing dunites of the southern part of platinum-bearing zonal Galmoenan dunite-cllinopyroxenite-gabbro plutonic complex (Koryak-Kamchatka belt, Russia) were analyzed. The age calculated by the tangent of the ¹⁹⁰Pt-⁴He isochrone slope angle equals 69.5 ± 4.9 mln years. The obtained age value coincides with the results of isotope datings, which were made previously by different methods of isotope geochronology.     

Generation of integral maps using the territory of a municipal district as an example

This paper further develops the ideas of V. B. Sochava’s Siberian school of thematic mapping concerning an integral approach in generating synthesis and assessment maps of the habitat on objective grounds confirmed by quantitative calculations. Maps of the natural environment display the invariant structure of the sites of a territory and their variable states. Integral indicators of the state of environment combine differentquality spatial information on the geographical location of the sites having regard to the scientific principles of qualimetry. An unbiased calculation of integral indicators is ensured through the use of the method of principal component analysis. The first principal component characterizes a maximum of variation in information on the geosystem, and the second component refers to a stable environment background. Their difference for each location corresponds to the potential of geosystem variability. The resulting integral indicators are displayed on assessment cartograms. The entire array of independent principal components is used for a classification of geosystems using the method of k-means clustering to create the typological map of the territory. Calculations are based on data for forest management of the Slyudyanka Leskhoz within the boundaries of the Slyudyanka municipal district of Irkutsk oblast. The territorial norm of the geographical environment corresponds to geosystems of the mountain-taiga belt of the Siberian stone pine and larch taiga on different-aspect slopes. Negative deviations from the norm are induced by high-mountain goletz and subgoletz geosystems on steep slopes, and positive deviations correspond to flat interfluves and gentle slopes.     

Upward high-energy field-aligned electron beams above the polar edge of auroral oval: observations from the SKA-3 instruments onboard the Auroral Probe (Interball-2)

A new phenomenon was found at the polar edge of the auroral oval in the postmidnight-morning sectors: field-aligned (FA) high-energy upward electron beams in the energy range 20–40 keV at altitudes about 3 R_E, accompanied by bidirectional electron FA beams of keV energy. The beam intensity often reaches more than 0.5 · 10³ electrons/s · sr · keV · cm², and the beams are observed for a relatively long time (3 10²–10³ s), when the satellite at the apogee moves slowly in the ILAT-MLT frame. A qualitative scenario of the acceleration mechanism is proposed, according to which the satellite is within a region of bidirectional acceleration where a stochastic FA acceleration is accomplished by waves with fluctuating FA electric field components in both directions.     

The manifestation of the principles of geoecological ethics: Environmental approach

We investigate the additionality of the principles of geoecological ethics and ethical geography from the perspective of the manifestation of the norms of human activity in the natural environment. Geoecological ethics is based on the through principles of sustainable development and responsibility for breaches of different-quality norms existing in nature, economy and society, and on social relations considered in different systems with due regard for the characteristics of geographical environment. The degree of responsibility is measured in dimensionless indicators of reliability (dependability) theory, the integrated hazard of activity with natural restrictions on the action on geosystems and departures from normative states. Ethical geography generates landscape-cultural norms of implementation of different kinds of activity on a territory. The general ethical laws and quantitative models and methods for responsibility assessment are special interpretations of the notions and axioms of general system theory adopted as the norm of organization of knowledge. The principles of geoecological ethics manifest themselves as a result of the interpretation of the general laws of ethics via the geohistorical environment, primarily in the form of responsibility for a departure from the environment-caused norms of activity. Ethical geography implies responsibility for the reliability of knowledge of the generally significant norms of the state and allowable changes in environment. A violation of geoethical norms and nature management normative will necessarily lead to negative changes in the living conditions of man and society.     

Magmatic and metamorphic evolution of the oceanic crust in the western flank of the MAR crest zone at 15°44′N: Investigation of cores from sites 1275B and 1275D,JOIDES resolution Leg 209

This paper reports the results of an investigation of a representative collection of samples recovered by deep-sea drilling from the oceanic basement 10 miles west of the rift valley axis in the crest zone of the Mid-Atlantic Ridge at 15°44′N (sites 1275B and 1275D). The drilling operations were carried out during Leg 209 of the drilling vessel JOIDES Resolution within the framework of the Ocean Drilling Program (ODP). The oceanic crust was penetrated to a depth of 108.7 m at Site 1275B and 209 m at Site 1275D. We reconstructed the following sequence of magmatic and metamorphic events resulting in the formation of a typical oceanic core complex of slow-spreading ridges: (1) formation of a strongly fractionated (enriched in iron and titanium) tholeiitic magmatic melt parental to the gabbroids under investigation in a large magma chamber located in a shallow mantle and operating for a long time under steady-state conditions; (2) transfer of the parental magmatic melt of the gabbroids to the base of the oceanic crust, its interaction with the host mantle peridotites, and formation of troctolites and plagioclase peridotites; (3) intrusion of enriched trondhjemite melts as veins and dikes in the early formed plutonic complex, contact recrystallization of the gabbro, and development in the peridotite-gabbro complex of enriched geochemical signatures owing to the influence of the trondhjemite injections; (4) emplacement of dolerite dikes (transformed to diabases); (5) metamorphism of upper epidoteamphibolite facies with the participation of marine fluids; and (6) rapid exhumation of the plutonic complex to the seafloor accompanied by greenschist-facies metamorphism. The distribution patterns of Sr and Nd isotopes and strongly incompatible elements in the rocks suggest contributions from two melt sources to the magmatic evolution of the MAR crest at 15°44′N: a depleted reservoir responsible for the formation of the gabbros and diabases and an enriched reservoir from which the trondhjemites (granophyres) were derived.     

Trapping of sensing radio waves in an artificial large-scale ionospheric cavity

The results of phenomenological analysis of data from oblique chirp sounding of the ionosphere in a 2007 heating experiment with possible recording of the effect of trapping sounding-radiation in an artificial ionospheric cavity and spotlighting it in the near (over the Earth’s surface) zone of the Sura facility are presented. The physical aspects of forming an additional trace on ionograms of oblique radio-sounding of the perturbed region of the ionosphere are discussed.     

Specific behavior of the radioemission wave field near the maximum usable frequency

The character of a change in the wave field in the frequency range near the maximum usable frequency is analyzed for the model of a simple ionospheric layer. The estimates of the characteristic scale of diffraction damping of the wave field in the frequency range, which are in rather good agreement with the experimental data of LFM or chirp sounding of the ionosphere on two mutually perpendicular paths, have been obtained.