Mud volcano as a feature of emergence in Caspian Sea

Abstract

An eruption occurred on Dashli Island, 75 km from Baku, on 4th of July 2021, at 21:51 local time. The island is known as the mud volcano and has a history of eruption. We suspected that mud volcano eruption causes emergence on this island. Thus, the effect of this 2021 eruption is investigated using a remote sensing technique. Processed Sentinel-1 and 2 images are employed for this aim. We considered pre- and post-eruption scenarios to evaluate the effect of this eruption on the island. Satellite image classification is used to calculate shoreline changes. Results show that Dashli Island with an area of about 8.55 ha before eruption is now expanded to about 21.8 ha (about 155% increase). The DInSAR method is used to estimate the ground displacement of the island. According to the results, a two-year-displacement before the eruption was between 0.18 and 0.2 m, while a five-month-displacement after the eruption is estimated to be between 0.32 and 0.4 m. Considering ground displacement pre- and post-eruption we estimated 62000 m3 land gaining, due to emergence. We concluded that mud volcano can be counted as a feature of emergence in Dashli Island.

Keywords

• Dashli Island
• Daşlı ada
• Mud volcano
• Eruption
• Emergence
• Sentinel-1