Reconstruction of the Earth’s surface temperature based on data of deep boreholes,global warming in the last millennium,and long-term solar cyclicity. Part 1. Experimental data

The most reliable pattern of climate changes is obtained using data of instrumental observations at the network of meteorological stations. However, the series of such data have short timescales (about 150 years). Indirect data from natural archives make it possible to judge specific features of climate changes in the more distant past. In contrast to indirect methods, when data are related to temperature through statistical correlations with air temperature, the borehole geothermal method makes it possible to directly determine the surface air temperature. The reconstructions of the temperature obtained using different indirect data for the Northern Hemisphere have been compared with the surface air temperature reconstructions based on the data of borehole thermometry and solar activity variations, and the possibilities of using the method in order to reconstruct long-term trends in climate changes have been indicated.     

Problem of the length of the current interglacial

The climate during the past hundreds of thousands of years has been characterized by a rather distinct periodicity of about 100000 yr with brief warming periods (interglacials) lasting approximately 10000–12000 yr. Today, mankind is living in an interglacial period that began about 11 ka ago. In light of the discussion about global warming observed in recent decades, which advocates of an anthropogenic impact associate with emission of greenhouse gases due to combustion of fossil fuel, the question arises concerning the duration of the current interglacial. The data available on climate change and solar radiation on a time scale of the last millions of years are critically analyzed in this article and the problem of the length of the current interglacial is discussed.     

Different-scale tendencies of the evolution of the composition of volcanogenic pyrite deposit ores

The changing contents and ratios of certain primary and secondary elements in the composition of volcanogenic pyrite deposit ores reveal two tendencies that have different scales of their manifestation in geological time and space. The first one is expressed in terms of the evolution of geochemical differences of deposit ores during relatively short periods of pyrite formation in some ore provinces. It is determined by the changing stages of tectonic development and corresponding alterations of magma composition within the provinces. The other tendency is global; it is expressed in terms of century-old changes of ore geochemical characteristics in the deposits that have developed in different pyrite formation epochs over the last 3.5 billion years, probably as a result of the differentiation of Earth material, a gradual temperature drop in the upper mantle, and the associated development of tectonic conditions and magma-formation mechanisms.     

Detailed seismicity mapping of the Altai-Sayan zone using large averaging areas

An improved technique is suggested for quantifying seismic activity over averaging areas of an arbitrary size. The example of the Altai-Sayan seismic zone is used to substantiate the choice of a 1° N × 2° E averaging area instead of the traditional one of 40×40 km². Maps compiled with averaging areas of different sizes can be spliced and correlated using a correction coefficient estimated in different models. The new seismicity map of the Altai-Sayan area covers more than 90% of the territory and provides a generalized image of activity being advantageous over the classic maps as it allows better correlation of regional seismicity with the tectonic setting. With larger averaging areas and, correspondingly, a greater amount of data in each area, one can obtain time series of seismic activity to be analyzed using mathematical statistics as a basis for mathematical modeling and simulation of the seismic process.     

Periods of Extremely High Rates of the Production of Cosmogenic 14C and Temperature Variation According to Data on the 40Ar Content in the Ice Layers for the Last 4000 Years

Geomagnetism and Aeronomy - The possible application of temperature reconstructions based on measurement of the 40Ar concentration in ice layers of the Greenland ice sheet to study past solar...     

Radiocarbon Data from the Late 18th Century as a Reflection of Solar Activity Variation,Natural Climate Change,and Anthropogenic Activity

Geomagnetism and Aeronomy - The data on the content of the 14C cosmogenic isotope in the natural archives make it possible to study the solar activity (SA) in the past centuries and millennia....     

Reconstruction of Heliospheric Modulation Potential Based on Radiocarbon Data in the Time Interval 17 000–5000 Years B.C.

Geomagnetism and Aeronomy - The results of reconstruction of the heliospheric modulation potential based on radiocarbon data for the time interval 17 000–5000 years B.C. are presented....     

Using Lineament Analysis to Identify Patterns in the Localization of Au Mineralization in the Taryn Gold Field in the Republic of Sakha (Yakutia)

Izvestiya, Atmospheric and Oceanic Physics - The development of geographic information systems and their growing application in Geology provide a unique opportunity to optimize the process of...     

Solar activity and cosmic ray variations as a factor of intensity of cyclonic processes at midlatitudes

Long-period variations in the cyclonic activity at middle and subpolar latitudes of the North Atlantic are studied on the basis of the data from the MSLP archive of the surface pressure (Climatic Research Unit, UK) for 1874–1995. It has been found that in the cold half year (the period of the most intense formation and development of extra-tropical cyclones) in the studied region, oscillations of the surface pressure with periods close to the main periods of solar activity (～80 and ～11 years) are observed. The obtained results make it possible to assume that solar activity and related variations in the galactic cosmic rays are one of the factors influencing the intensity of cyclonic processes at midlatitudes on the time scales of ～10 to ～100 years.