High-resolution vertical electrical sounding survey: investigation of subsurface structures at dashgil´s mud volcano, Azerbaijan

High-resolution electrical resistivity method was applied to investigate subsurface structure of Dashgil mud volcano in Azerbaijan. The field work performed on one profile with the use of four-electrode symmetrical installation AMNB. ERA-MAX electromagnetic prospecting equipment with an operating frequency of 4.88 Hz is used for the field measurements. A total of 21 VES using Schlumberger arrays were carried out along NW-SE oriented profile. Data processing was performed using inverse modeling. True resistivity values of the subsurface model are determined by curve matching with the curve of apparent resistivity values. Data interpretation is performed to estimate subsurface lithology and rock layers that are identified as the layer of hot groundwater aquifers. The sections of apparent resistivity and geoelectrical section based on the values of specific electrical resistance were composed, which were then converted to a litho-geophysical section. It is found that the specific electrical resistance of rocks composing the geological environment changes in the range of 0,1-35 Ohm-m. It is assumed that the eruption times of Dashgil volcano can be roughly determined based on the number of layers obtained from resistivity sections. In this study we determined it to be 5-8 times, which is consistent with the noted data in the catalogue of mud volcanoes eruptions of Azerbaijan.