A mysterious new island emerged in the Caspian Sea following the eruption of the Kumani Bank mud volcano, located approximately 25 kilometers off the eastern coast of Azerbaijan. Satellite images captured by NASA's Earth Observatory documented the island’s appearance in February 2023 and its subsequent erosion over the following months.
The island, estimated to be about 400 meters wide, was first observed on February 14, 2023, near the site of the Kumani Bank mud volcano. According to The Western Journal, the Operational Land Imager (OLI) instruments on NASA's Landsat 8 and Landsat 9 satellites captured images showing the new landmass with a long plume of sediment extending away from it.
Mud volcanoes are geological formations that erupt a mixture of mud, gases, and liquids from beneath the Earth's surface. Azerbaijan is known for having an unusually high concentration of these features, with over 300 mud volcanoes recorded both on land and in the Caspian Sea. The high density is primarily due to the convergence zone of the Arabian and Eurasian tectonic plates in the region.
The Kumani Bank mud volcano has a history of eruptive activity, having recorded eight eruptions since 1861. These eruptions previously produced temporary islands, which were eventually eroded by sea processes. The strongest documented eruption occurred in 1950, generating an island 700 meters wide and 6 meters high.
"Mud volcanoes like Kumani Bank are strange and wonderful features that remain largely understudied and misunderstood," said geologist Mark Tingay from the University of Adelaide, according to Focus Online. Tingay explained that mud volcanoes typically form in areas with active tectonic activity or high sedimentation rates. Pressure from below the surface forces a mixture of mud, gas, and liquid to escape to the surface, creating unique and often temporary features.
The recent emergence and erosion of the island provided scientists with a rare opportunity to study the life cycle of such transient landforms. NASA's Earth Observatory used images from the OLI and OLI-2 instruments on the Landsat satellites to document the island's formation and shrinkage. According to The Economic Times, satellite images captured on November 18, 2022, showed an empty expanse of sea, while images from February 14, 2023, revealed the new island. By December 25, 2023, the island had almost entirely eroded away.
Mud volcano eruptions in this region are often short-lived but intense, capable of expelling large quantities of material, gas, and even flames into the air. In some cases, eruptions have produced striking columns of fire that reach hundreds of meters in height. Although it is not known whether the 2023 eruption at Kumani Bank was fiery, earlier eruptions of this and other nearby mud volcanoes exhibited such dramatic effects.
Despite their fascinating nature, mud volcanoes can pose hazards due to their potential to move huge amounts of material in a short time and even emit flammable gases like methane.
The mud volcanoes of Azerbaijan are linked to the vast hydrocarbon system of the South Caspian Basin.
El Confidencial reported that some mud mounds in the northern lowlands of Mars may have formed due to similar processes when gas- and liquid-rich sediments came to the surface.
This article was written in collaboration with generative AI company Alchemiq