A new generation of Pulkovo observatory meridian instruments and the first results of observations

The results of investigations and observations with classical meridian circle MK-200 and photographic vertical circle (PVC) after its modernization and automation are discussed. The data concerning the stability of the instrumental system and the flexure of the Pulkovo Horizontal meridian circle (HMC) are given. New work on the establishment of in axial meridian circle in Nikolaev, Ecker meridian circle and reflecting one in Pulkovo is mentioned.     

Assessment of the total and anthropogenic organic matter runoff from the territory of the Commonwealth of Independent States

This article provides an assessment of river runoff of organic matter into seas from the territory of the Commonwealth of Independent States, its anthropogenic component and tendencies in their changes over certain periods from 1936 to 2000. The distribution within a year, modules, runoff ratio of organic matter and major ions are discussed.     

Deep electromagnetic sounding of the lithosphere in the eastern Baltic (fennoscandian) shield with high-power controlled sources and industrial power transmission lines (FENICS experiment)

The paper addresses the technique and the first results of a unique experiment on the deep tensor frequency electromagnetic sounding, the Fennoscandian Electrical conductivity from results of sounding with Natural and Controlled Sources (FENICS). In the experiment, Energy-1 and Energy-2 generators with power of up to 200 kW and two mutually orthogonal industrial 109- and 120-km-long power transmission lines were used. The sounding frequency range was 0.1–200 Hz. The signals were measured in the Kola-Karelian region, in Finland, on Svalbard, and in Ukraine at distances up to 2150 km from the source. The parameters of electric conductivity in the lithosphere are studied down to depths on the order of 50–70 km. A strong lateral homogeneity (the one-dimensionality) of a geoelectric section of the Earth’s crust is revealed below depths of 10–15 km. At the same time, a region with reduced transverse crustal resistivity spread over about 80 000 square kilometers is identified within the depth interval from 20 to 40 km. On the southeast the contour of the anomaly borders the zone of deepening of the Moho boundary down to 60 km in Central Finland. The results are compared with the AMT-MT sounding data and a geodynamic interpretation of the obtained information is carried out.     

Results of monitoring the geomagnetic variations at the Magadan and Paratunka observatories

We analyze the magnetic tensor and tipper data in the interval of periods from a few minutes to a few hours for the geomagnetic time series of 2007–2008. The frequency responses, the polar diagrams, and the real and imaginary induction arrows which reflect the effects of geoelectric heterogeneities are calculated. The monitoring of the tipper and tensor data series revealed the annual variations in these parameters, which are caused by the changes in the electric conductivity of the lithosphere. The anomalous variations identified in the behavior of the magnetic tipper and tensor are probably due to earthquakes with M ≥ 6.3.