Disturbances in the ionosphere and atmosphere caused by the solar eclipse of August 11, 1999

Results of comparing ionospheric radio noise at wavelength of 2 m at midlatitudes to the data of the ionospheric vertical sounding during the partial phase of the solar eclipse of August 11, 1999, are presented. Disturbances in the ionospheric layers, radio noise of the ionospheric plasma, and variations and fluctuations in the atmospheric pressure at the Earth surface during the eclipse are considered. The parameters of the Lamb wave, which propagated with velocity of 300 m/s from the region of the total phase of the eclipse are determined. The Lamb wave characteristics in the summer midlatitude and auroral ionosphere have been compared.     

Environmental monitoring in a gas production area on the northwestern Black-Sea shelf

The results of long-term seasonal oceanographic observations conducted by YugNIRO from 1955 to 1991 in standard cross-sections on the northwestern shelf of the Black Sea and data obtained by monitoring oil and chemical pollution of the marine environment from 1987 to 1993 in the area of gas deposit development are systematized and statistically treated. The oceanographic conditions of pollution field formation in this region are studied. The dynamics and distribution of total concentrations of oil products and microelements (Hg, Cu, Pb, Cd, and Cr) in water and bottom sediments are examined in the areas in Karkinitskii Bay where permanent offshore platforms are operated. The obtained results are compared with data on the background environmental pollution of the Black Sea and World Ocean. A hypothesis is offered to elucidate the possible causes and mechanisms through which offshore gas production affects the hydrochemical conditions on the shelf. The monitoring data are said to be a necessary information basis for the prediction of pollution dynamics in Karkinitskii Bay with the use of a box-type hydroecological model of petroleum hydrocarbon biotransformations in water, and approaches for the use of these data for this purpose are outlined.     

Biotransformation of oil hydrocarbons in Karkinitskii Bay of the Black Sea: Assessment based on mathematical modeling

The transformation conditions of oil hydrocarbons in water are considered for the case of Karkinitskii Bay, the Black Sea, where gas deposits have been developed actively in recent years and oil product pollution of marine environment has been recorded repeatedly. Data on measured oil hydrocarbon concentrations, their input into the northwestern part of the Black Sea, and experimental estimates of oil decomposition in the marine environment are presented. The biotransformation conditions of oil hydrocarbons are simulated by reproducing the biochemical activity of microflora and effecting substrate consumption processes, metabolic product excretions, and biomass decay. These processes maintain the biogenic substance turnover in water environment. The calculations are based on the morphometric characteristics of Karkinitskii Bay, and mean long-term data on the monthly dynamics of marine environmental characteristics (temperature, light intensity, transparency, atmospheric precipitation, and the characteristics of water regime and Danube runoff). A check calculation was performed to reproduce the concentration dynamics of biogenic substances and oil products with allowance made for the effect of river runoff and background pollution of the marine environment. The numerical scenarios take into account the marine environmental pollution conditions (an immediate discharge of 1000, 500, or 200 t of oil products per week) in winter, spring, summer, and autumn. The obtained model estimates of the rates of oil product decomposition and oxygen consumption are shown to agree well with experimental data. The time required for the concentration of oil products to reach the MAC after pollution of the marine environment is estimated.     

Structural-functional organization of biocenoses and the ichthyofauna of the Moskva River in its urban reach

Materials of structural-functional studies regarding the organization of the Moskva River ecosystem within the boundary of the city are presented, and the impact of the treated water discharged from Kur’yanovskaya Aeration Station onto aquatic biota is assessed. The conclusion is made that the structural-functional organization of biocenoses in different river reaches is related with the environmental factors that form under the effect of this water.     

贵州安龙县阿油槽岩溶塌陷浅析和防治对策

阐述分析了阿油槽地区岩溶塌陷的水文地质背景,对该地区产生岩溶塌陷的基本条件、诱发因素及形成过程进行了分析,并针对其具体情况提出了岩溶塌陷防治及治理的措施。     

Association of sediments in fluvioglacial deltas (Evidence from Northwesternmost Russia)

Rock associations in fluvioglacial deltas reflect climatic cyclicity. Climatic cycles determined the accumulation of sediments in the association of hydrodynamic, debris, and turbidity flows. Hydrodynamic flows formed successively the near-summit part of the delta (pebble and boulder) and its frontal slope in the course of accumulation of the pebble, sand-pebble or sandy and, less common pebble-boulder layers inclined toward the basin. Decrease in energy of flows in the basin resulted in successive reduction of particle grain-size along these layers and toward distal areas of the delta during its formation. The formation of the deltaic frontal slope was followed by the initiation of debris and turbidity flows. They spread along the floor of marine and freshwater basins and deposited successively gravel material, different-size sands, and varved clay. In the study region, sediments of the association under consideration include sand and sand-gravel deposits (up to 40% of total reserves in the Murmansk region) and almost all known brick clay deposits.     

Barium and strontium in the upper mantle of the Pamirs and Tien Shan

The distribution of Ba and Sr in deep-seated xenoliths, mantle alkaline melts, and their minerals from the Pamirs and Tien Shan and some other regions was considered. In contrast to ordinary magmatic series, the mantle rocks show a correlation of Sr with both Ca and alkalis. The most extensive accumulation of Ba and Sr in the upper mantle occurs during the processes of mantle metasomatism and melting of metasomatized materials. The influx of these elements is probably related to ultradeep plume-type sources. Ba and Sr were transported from the mantle into the crust by both high-temperature alkaline melts and low-temperature hydrothermal solutions. It is supposed that the late Alpine celestite deposits of the huge Sr province of the Mediter-ranean belt are of mantle origin. Geochemical provinces show distinctive concentrations and proportions of Ba and Sr in mantle-derived alkaline basic rocks, metasomatic rocks, and their minerals. The type of Ba-Sr relations is inherited by crustal rocks.     

喜玛拉雅“东构造结”地区特异重力场的探讨

跨越中、印、缅三国交界的青藏高原东南的喜玛拉雅“东构造结”地区（92°E~97°E，26°N~30°N）一半以上的面积尚没有重力测点，是重力数据空白区,故无法直接研究其重力场特征与深部地壳结构（构造）.本文分析了卫星重力异常的特性，提出应用卫星重力异常作为近似空间重力异常，并作布格改正后，得到的布格重力异常具有与该地区地形高程呈镜像相关的特征，可用以研究深部地壳结构.据三条重力剖面计算得到该地区三个地壳深部结构剖面的结果，给出青藏高原地壳厚度>70 km；喜马拉雅造山带为55 km左右；布拉马普特拉河谷盆地为33~35 km；那加山山脉地区为40~45 km，显示出三者为三个不同的构造单元.同时给出布拉马普特拉构造单元为相对高密度的刚性物质构成，随着印度洋板块向北运移，在碰撞、挤压下，插入青藏高原东南缘一带.导致该地带的强烈构造运动，和频发大、小地震.最后提出了几点认识和建议.