scholarly journals Estimation of activity the methane seepage from the Black Sea floor using MODIS images and geosciences data

Author(s):  
T. A. Melnichenko

The publication presents the results of a certain stage of the study: the features of methane gas seepage characteristics in the transition zone of shelf-continental slope in the region of the Dnieper Paleodelts in the northwestern part of the Black Sea are identified, taking into account the data set: information of satellite images and of geological-geophysical (acoustic) data. About 2000 of the MODIS satellite images (product MOD021KM) are acquired in stages over one year period. The image processing was carried out in the GIS environment. It was established that the volume of methane gas seepage on the investigated site is fixed on satellite images and is most pronounced during increased seismotectonic activity (activation of earthquakes in the Black Sea region) - this is due to the tectonic structure of the study area, which is in the regional plan on the edge of the Eastern European platform, and in the local area, is the Dnepr paleo-delta in the zone of decomposition, which is an additional factor for gas outlets here. On satellite images small clouds are observed in cloudy weather or absence of clouds on the background of continuous clouds. This is due to the physical properties of methane, which is (according to geochemical studies) about 99% of the released gas. Methane rising from the bottom of the sea to the surface, and then to the troposphere is much colder than the surface water and warmer than the atmosphere layer, which provokes the formation of condensate over the site with methane gas seepage, and when the weather conditions change, forming a rainy cloud with a sharp drop in temperature, the volume of methane gas of seepage up are much warmer than clouds, forming a cloudy area on a background of continuous clouds. This phenomenon is recorded in various spectral (thermal and infrared) bands in satellite images (NASA – MODIS, NOAA, etc.), methane rising to the lower layers of the atmosphere intensively absorbs thermal radiation of the Earth in the infrared spectral region at a wavelength of 7.66 µm. It enables to determine the methane gas seepage in satellite images for future studies of gas outlets from the bottom of the sea, taking into account the geological information and additional hydrological  and weather data. The conducted monitoring of the satellite images showed that during the period of increased seismic activity in this region (in particular under the influence of the zone Vranch), it directly affects the tectonic situation in the northwestern part of the Black Sea and increases the emissions of methane gases from the bottom of the sea, which are then recorded on the MODIS sensor. 

Author(s):  
Marina Krylenko ◽  
Marina Krylenko ◽  
Alexandr Aleynikov ◽  
Alexandr Aleynikov ◽  
Viacheslav Krylenko ◽  
...  

The Anapa bay-bar is located in the northwestern part of the Black Sea. With the goal in mind to determine the short-term dynamics of the Anapa bay-bar we analyzed satellite images from 2003 to the present. Depending on the hydro-lithodynamical situation the shoreline configuration during storm can vary from a rectilinear to sinusoidal forms. There are regions of local erosion or accumulation whose formation is related to the alongshore motion of sediments and dynamics of underwater bars. Comparison of the data on 1965 and 1966 showed that in this period the amplitude of the shoreline position was more than 20 m but average displacement of the shoreline for 13 months was only 0.8 m. This study showed that for the analysis of changes in the shoreline position is necessary to consider the configuration of the coastline at the time of each observation and the local dynamics.


Author(s):  
Marina Krylenko ◽  
Marina Krylenko ◽  
Alexandr Aleynikov ◽  
Alexandr Aleynikov ◽  
Viacheslav Krylenko ◽  
...  

The Anapa bay-bar is located in the northwestern part of the Black Sea. With the goal in mind to determine the short-term dynamics of the Anapa bay-bar we analyzed satellite images from 2003 to the present. Depending on the hydro-lithodynamical situation the shoreline configuration during storm can vary from a rectilinear to sinusoidal forms. There are regions of local erosion or accumulation whose formation is related to the alongshore motion of sediments and dynamics of underwater bars. Comparison of the data on 1965 and 1966 showed that in this period the amplitude of the shoreline position was more than 20 m but average displacement of the shoreline for 13 months was only 0.8 m. This study showed that for the analysis of changes in the shoreline position is necessary to consider the configuration of the coastline at the time of each observation and the local dynamics.


1995 ◽  
Vol 32 (7) ◽  
pp. 63-70
Author(s):  
I. Ethem Gönenç ◽  
Oguz Müftüoglu ◽  
Bilsen Beler Baykal ◽  
Ertugrul Dogan ◽  
Hüseyin Yüce ◽  
...  

Unlike other seas of the world, the Black Sea shows unique quality and trophic properties. Fortunately, only the upper layer water of the Black Sea is introduced into the Bosphorus and has a significant effect on the quality and trophic conditions of the Marmara Sea. These effects are discussed in the light of data obtained from collaborative efforts of Turkish and Romanian research institutions and processed satellite images. In conjunction with these discussions, recommendations for a suitable effluent disposal strategy for Istanbul's wastewater have been given.


2003 ◽  
Vol 48 (10) ◽  
pp. 135-142 ◽  
Author(s):  
D.Z. Seker ◽  
C. Goksel ◽  
S. Kabdasli ◽  
N. Musaoglu ◽  
S. Kaya

The Riva River is located on the Anatolian (Asian) side of Istanbul by the Black Sea coast, with a wonderful sandy beach and delta formation which has been selected as the study area. The Riva is the largest river in this region, which flows into the Black Sea and also gives its’ name to the area. The river carries some amount of sediments to the Black Sea. These particles cause considerable changes not only in the bed bathymetry and coastal boundaries of the river but also along the coastline of the Black Sea. The aim of this study is to determine these variations by means of satellite data and GIS. In the study, satellite images dated 1975, 1984, 1992 and 2001 have been used. At the end of the study, the possibility of observing bathymetric changes in front of the coastline by means of satellite data has been investigated and results were evaluated and visualised by means of GIS.


2021 ◽  
Author(s):  
Valentina Yanko ◽  
Anna Kravchuk ◽  
Irina Kulakova ◽  
Tatiana Kondariuk

<p>This <span>presentation</span> represents a case study that reviews research into the relationship between meiobenthos distribution and concentrations of hydrocarbon gases (HG), primarily methane, in the sediments of the northwestern part of the Black Sea, including gases released by mud volcanoes and gas seeps. Evidence forming the basis of this research comes from meiobenthos here represented by 29 species of benthic foraminifers, 7 species of ostracods, and 44 species of nematodes. The potential use of these meiobenthic organisms as indicators of gaseous hydrocarbons reservoirs existing under the seabed is evaluated according to two linked axes, namely the dual analysis of abiotic factors (physical and chemical parameters of the water column, gasmetrical, geochemical, lithological, and mineralogical properties of the sediments) and biotic characteristics (quantitative and taxonomic composition of foraminifers, nematodes, and ostracods). Studies of this kind have been directed toward developing interdisciplinary methods to improve the search for HG accumulations, especially methane, under the seabed. Development of such methods might have substantial socio-economic importance for the economy of Ukraine as well as that of other Black Sea countries, and such methods might also contribute to the sustainable development of Black Sea ecosystems.</p>


2019 ◽  
Vol 40 (4) ◽  
pp. 467-480 ◽  
Author(s):  
Miriam Römer ◽  
Heiko Sahling ◽  
Christian dos Santos Ferreira ◽  
Gerhard Bohrmann

2020 ◽  
Author(s):  
Andrey Serebryany ◽  
Valeriy Bondur ◽  
Viktor Zamshin

<p>When conducting work in the fall of 2015 on the Black Sea northeast shelf, we recorded internal waves, the unusualness of which attracts special attention for the following reasons. For the first time in 40 years of internal waves observations in the Black Sea, such high waves with amplitudes of 14–16 m were measured. The generation of these anomalous waves was connected with a cold atmospheric front passing over the sea. It was the first experimental evidence in the sea of such mechanism for internal waves generation. The observed internal waves had a clear seen character of nonlinear soliton-like waves.</p><p>We met the train of internal solitons during a sub-satellite survey conducted in the sea from a motor yacht equipped with ADCP “Rio Grande 600 kHz” in the waters near Cape Tolsty. The train was found at a point of the sea with a depth of 33 m and then was recorded on seven multidirectional tacks oriented normal to the coast. It moved across the shelf to the coast along the bottom thermocline, while the bottom currents accompanying it had a northwestern coastal orientation. The train included four waves of a soliton-like shape with sharpened crests and flattened troughs. Their lengths were 100-110 m, heights up to 14-16 m, vertical velocities in orbital currents reached 0.15-0.20 m/s. Another property of nonlinear waves was also expressed - the amplitude ranking of waves in the train. Traced on successive tacks for 2.5 hours, internal waves had preserved the soliton-like shape and as well the strong vertical component in their orbital currents. Despite the fact that the train was moving along the bottom thermocline, the effect of internal waves was sufficient to appear on satellite radar images of the sea surface of the study area. The performed processing of satellite images confirmed the wave parameters measured by contact methods.  An interesting fact of a long accompaniment of internal solitons by a school of fish was discovered. Fishes were concentrated in areas where internal waves carried the components of fish food supply to the surface from the bottom layers. The work was partially supported by RFBR grant 19- 05-00715.</p>


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