A review of Holocene avulsions of the Tigris and Euphrates rivers and possible effects on the evolution of civilizations in lower Mesopotamia

The role of avulsion in the evolution of civilization in lower Mesopotamia is widely recognized. Ancient settlements are closely associated with abandoned courses of the Euphrates and Tigris Rivers. This paper discusses avulsion history, controls of avulsions, their effects on civilization evolution from 7000 to 1000 yr B.P., and interactions between human activity and channel‐network evolution based on previous archaeological and geomorphological surveys, analysis of cuneiform texts, maps, satellite photos, and limited geological data. Settlement distribution in ancient Mesopotamia is modeled in relation to avulsion styles, as well as channel and sedimentation patterns. Avulsion belts are suggested as places where urban settlements emerged and were sustained. Multiple channel networks and avulsion belts created large, naturally irrigated areas, fostering the efficient agriculture needed to sustain dense rural and urban settlements. After channel networks were abandoned during delta evolution, largescale canal construction was required to sustain settlements but still could not prevent their decline. © 2005 Wiley Periodicals, Inc.     

Numerical simulation and spectral analysis of the November 15, 2006, tsunami in the Kurile-Kamchatka region

Numerical simulation of the earthquake and tsunami of November 15, 2006, and the spectral analysis of the distribution of the wave fields in the basin made it possible to analyze in detail the tsunami generation by a seismic source and the pattern of the wave propagation through the Bussol Strait, as well as to estimate the influence of this strait on the further propagation of the waves in the basin of the Sea of Okhotsk and the near-field zones of the Kurile and Japanese Islands.     

Structural specificity of pleistocene loess and soil formation of the southern Russian plain according to materials of Eastern Priazovie

Doklady Earth Sciences -     

Isotopic-geochronological systems in metamorphic rocks: Pon’goma Island,Belomorian mobile belt

Several isotopic methods (U-Pb, Sm-Nd, Rb-Sr, and K-Ar) were applied to different rock-forming and accessory minerals to decipher the chronology of events in a separate segment of the Belomorian mobile belt. Enderbites intruded supracrustal rocks at 2.73 Ga and granodiorites were emplaced at 2.41 Ga. Immediately afterwrads, a permeable schistosity zone was formed along the enderbite-granodiorite contact. Isotopic data indicate that this zone served as a pathway for heat and fluid. The retrograde stage of regional metamorphism and subsequent cooling continued from 1.89 Ga till ～ 1.46 Ga.The cooling rate of the Pon’goma Island rocks is similar to that of other Precambrian complexes and amounted to ～1.5⁰/Ma, which is consistent with previous data on the northern segment of the Belomorian belt. Based on isotopic geochronological data, two tectonometamorphic scenarios can be proposed for the evolution of the Belomorian belt. The first scenario suggests long-term regional metamorphism, i.e., lengthy residence of the Archean and Lower Proterozoic rocks at a significant depth and high temperatures. Geochronological data for different systems (U-Pb, Sm-Nd, Rb-Sr, and K-Ar) suggest Caledonian hydrothermal cryptometamorphic processes. However the rocks of this age are absent from the study area.     

Variations of the Blazar AO 0235+164 in 2006–2015

The results of optical, radio, and gamma-ray observations of the blazar AO 0235+16 are presented, including photometric (BV RIJHK) and polarimetric (R)monitoring carried out at St. Petersburg State University and the Central (Pulkovo) Astronomical Observatory in 2007–2015, 43 GHz Very Long Baseline Interferometry radio observations processed at Boston University, and a gamma-ray light curve based on observationswith the Fermi space observatory are presented. Two strong outbursts were detected. The relative spectral energy distributions of the variable components responsible for the outbursts are determined; these follow power laws, but with different spectral indices. The degree of polarization was high in both outbursts; only an average relationship between the brightness and polarization can be found. There was no time lag between the variations in the optical and gamma-ray, suggesting that the sources of the radiation in the optical and gamma-ray are located in the same region of the jet.     

Giant thunderstorm cloud at the Far East of Russia

The process of the development of the giant thunderstorm cloud of 500 × 700-km size at the Far East of Russia is considered. Its formation is explained by the intensification of the electromagnetic radiation from Earth’s crust fractures before the earthquake in Amur region.     

Railroad bed bearing strength in the period of thawing and methods of its enhancement

The practice of building and operating of railroad beds shows that the greatest at enuation of soils occurs in the spring, during their transition from the frozen to thawed state. The greatest influenc...     

Development of the steppe zone in southern Russia based on the reconstruction from the loess-soil formation in the Don-Azov Region

Herbaceous communities in forest ecosystems on the southern part of the Russian Plain appeared in the Middle Miocene (??10 Ma BP). In the Late Miocene (??7 Ma BP), feather-grass steppe associations appeared among them. In the time span of 2.7 to 2.1 Ma BP (i.e., in the Early Quaternary, according to the current chronostratigraphic scale), the steppe zone arose on the southern Russian Plain in the Don-Azov Region. Seven stages of this zone development here have been distinguished throughout the Quaternary. The first one (Eopleistocene-Early Pleistocene) was characterized by savanna-like subtropic ecosystems. Then, in the Middle Pleistocene, the temperate zone ecosystems (tallgrass prairie-like steppes) developed here and were followed by steppe ecosystems close to the modern ones in Central Europe. The ecosystems of rich-species forb steppes developed in the Late Pleistocene. Finally, in the optimum of the modern interglacial (Holocene), steppes became similar to the modern ones here, but with a slightly higher precipitation. The general trend is characterized by reduction in heat and water provision and increase in aridization progressing from earlier to later stages.     

The van earthquake on October 23, 2011: Natural and technogenic causes

A measurable effect of mass bombing on weak to moderate seismicity, endogenous microseism intensity, and acceleration of tectonic processes has been found. This effect is seen in the regime of strong and catastrophic earthquakes, a decrease in magnitude and time for their preparation, and lesser seismic hazard. The M = 7.8 Van Earthquake on October 23, 2011, was induced to occur early due to mass bombing in Libya and other regions of North Africa; however, the induced character caused its magnitude to be less by several tenths than it might have been.