Monitoring of mud-volcanic fluid manifestations in the Caspian Sea according to multispectral satellite data

In this paper, 180 cases of mud-volcanic fluid (MVF) manifestations on the marine surface and in the near-surface layer of the Caspian Sea in the area of Cheleken-Livanovsk Rise in 2019-2021 were detected and studied based on the results of satellite monitoring using multispectral satellite data. For the areas of MVF manifestations, the reflectance was analyzed in 7 spectral bands of the Landsat-8 and Sentinel-2A/B equipment in the wavelength range of 0.44–2.2 µm. Significant positive contrasts in Violet (~0.44 µm), Blue (~0.48 µm), and Green (~0.56 µm) spectral bands due to the presence of suspended matter and gas bubbles in the near-surface layer of the water column were detected in the areas of MVF manifestations. Mathematic expectations of Weber contrasts in those spectral bands varied in a range between С~0.47 and С~0.77. Complex analysis of spatiogeometric MVF manifestation characteristics and region bathymetry map allowed us to find coordinates of emission sources that corresponded to the peak of the mud-volcanic shoal.