by Lev Eppelbaum,Youri Katz,Zvi Ben-Avraham

2023,2 (2);10.58396/gges020202 - 18 Feb 2024

The catastrophic earthquakes in Eastern Turkey (Eastern Mediterranean) require their geodynamic understanding. The two most decisive events with magnitudes of 7.95 and 7.86 on 06.02.2023, followed by a series of more than 10,000 significant aftershocks. These tragic events led to the death of more than 60 thousand people. The above values indicate the colossal tension created in the Earth's crust. The region where these strongest earthquakes occurred is a complex junction zone of four tectonic plates: Eurasian, Arabian, African, and Anatolian. The joint movement of these plates (consisting, in turn, of tectonic elements of different ages) occurs at an average rate of 6–18 mm per year. After two marked powerful shocks and a series of aftershocks, some sectors of the Anatolian plate shifted to the southwest by more than 11 meters. Our recent publications indicated the presence of a giant, rotating quasi-ring structure below the Easternmost Mediterranean. This research contains significant newly obtained data. The quantitative analysis of the sat-ellite-derived gravity data indicates the lower mantle occurrence of the anomalous target. Examination of the geoid anom-alies map also testifies to the deep origin of this structure. The regional seismic tomography data confirm the presence of anomalous zones at a depth of 1500-1700 km. The GPS vector map and the comprehensive review of paleomagnetic data display the counterclockwise rotation of this structure. Analysis of the recently constructed magnetic field ΔZ pattern commonly proves the presence of this quasi-ring structure. The newly developed paleobiogeographic map is consistent with the proposed physical–geological model. A widespread analysis of tectonic, petrological, and mineralogical data implies a connection between the discovered deep structure and near-surface processes. A crucial for understanding the nature of the considered seismic stress is its location near the expressed bend of the Mesozoic terrane belt, where the Arabian Plate is deeply intruded into the Alpine-Himalayan belt. Thus, the rotation of this giant deep structure may accu-mulate the stress effect retrieved from the satellite, airborne, and surface geophysical observations. We propose that this stress, along with the known Earth’s crust seismological activity in this region, is the causative reason for the catastrophic geodynamic events in Eastern Turkey.

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by Carlos Junquera Rubio

2023,2 (2);10.58396/gges020201 - 15 Jan 2024

Gold was known in Peru before the arrival of the Spanish. European mining in the 16th century operated on the coast, and in the Andes, but not in the tropical jungle. The current Peruvian department of Madre de Dios was rich in rubber, and the search for this wealth first meant a great negative impact conducted by strangers, but they created social problems, ethnocides, and destruction in the tropical forest. In 1973 gold appeared on the river beaches, in the Laberinto region. Gold is always an attraction, and the strange population comes soon with the hope of becoming rich, but this is not easy. In this large Peruvian region, gold mining is conducted with traditional means that involve washing the sand with water, and the gold is separated with mercury. The high price of gold has implied informal, and extremely negative development for people, and tropical landscapes. Peruvian authorities have not been able to control the extraction areas but have tolerated illegal activities. The negative impact on the environment devastates, according to calculations, about 150,000 hectares each year, and about 50,000 kilograms of mercury are used to amalgamate the gold.

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by Lushvin Petr Vladimirovich,Buyanova Marina Olegovna,Chelidze Nikita Sergeevich

2023,2 (1);10.58396/gges020105 - 25 Jul 2023

Historical fluctuations in the level of the Caspian Sea are not yet amenable to reliable forecasting. The riches of the sea and changes in its level do not leave the administration alone, in sometimes paradoxical, ways of regulating the forces of nature. Recent decades have been characterized by significant shallowing of the sea-lake (≈1 m). This is mainly due to the frequent Volga low water, whose runoff accounts for > 70% of all river waters (instead of the characteristic values of the annual Volga runoff of 230-330km3 , less than 215km3 often come). To dampen the level, it is possible to either direct water from other river basins into the sea, which has been proposed repeatedly before, or reduce losses on streams. In this work, the latter is proposed - to regulate the evaporation of water from the Volga delta, which has grown by almost an order of magnitude. Of the ≈9 thousand km2 of the delta area, > 70% is covered with reed reeds. In summer floods, reeds evaporate 5-9 times more intensively than the water surface. The reduction of even half of the thickets will "save" billions of tons of Volga runoff from premature evaporation, dampens the level of the Caspian Sea. Another problem in the south of Russia is massive fires, both natural and anthropogenic genesis. In the spring, last year's dried reeds burn massively, raising the temperature of the environment, contributing to the growth of evaporation in the region. When damping the area of reeds for 15-25 years, an additional 100km3 would flow into the sea, which would compensate for the shortage of Volga runoff. The previously stated approach was not so effective due to the smaller size of the delta, although, implicitly, it was used, however, regardless of the course of sea level - in the USSR, 5 reeds were harvested in the Volga delta for the needs of a cell-cardboard plant (which contributed to minimizing the number of fires in the delta). A reduction in reeds at times in the floodplains and deltas of the Volga, Don, Kuban and Terek rivers (an area of up to 100 thousand km2 ) would give additional water for irrigation, reduce the number of fires in the Southern Federal District at times, which regionally minimized the current global warming.

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by Aditi Singh,Mahes Kumar

2023,2 (1);10.58396/gges020104 - 18 Jul 2023

Fog plays a significant role in many environmental and ecological processes. The aerosol particles present in the atmosphere becomes fog droplets due to condensation of water vapor on them in high humidity conditions. The formation and intensity of fog over an urban area depends on various factors that may promote or mitigate the process. The combustion processes are responsible for the presence of air pollutants in the atmosphere. The urban heat island effect may raise the temperature, lower the humidity and can even change the wind pattern of any region. The urban areas have often reported increase in frequency of fog due to emissions of air pollutants. The objective of the present study is to analyze the effect of air pollutants in formation fog over Delhi. The concentrations of air pollutants and meteorological observations are utilized for a period of six years in the present work. The study focuses on examining the dominant factors involved in formation of fog. It is found although high values of air pollutants aid in formation of dense fog but relative humidity is the most important factor that influence the formation of fog.

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