This Island in the Caspian Sea Is Almost Gone

An island created by the eruption of a mud volcano in the Caspian Sea is finally going the way of the dodo, based on satellite images of the structure.

The island formed in early 2023, when a mud volcano in the Caspian Sea’s Kumani Bank, about 15 miles (24 kilometers) off the coast of Azerbaijan, burst. The landmass is called Chigil-Deniz, but based on NASA satellites, it will soon be no more. After two years, erosion has condemned the island to Davy Jones’ Locker.

The images above show the area in November 2022 before the island appeared (left), February 2023 as it emerged (center), and December 2024 (right). NASA’s Landsat 8 and 9 satellites captured the images. As you can tell, the island was not there, then it was there, and is now a mere pinprick compared to its former size.

The Kumani Bank’s exposed island off the Azerbaijan coast. Image: NASA Earth Observatory images by Wanmei Liang, using Landsat data from the U.S. Geological Survey.

Volcanic eruptions form islands because pressure beneath the planet’s surface will push fluids, gases, and sediments to the surface, often explosively. Sometimes those events create land (see above), but sometimes they destroy it; the 2022 Hunga Tonga-Hunga Ha’apai eruption was so explosive it destroyed most of the island where it occurred, even though the volcano was underwater.

According to University of Adelaide geologist Mark Tingay, the island measured about 1,300 feet (400 meters) across when it first formed in late January and early February 2023. But by last month, the bank’s protruded island had significantly diminished.

Mud volcanoes are common in the region; according to the same release, Azerbaijan and the Caspian Sea are host to more than 300 of the remarkable structures. In 2021, one such volcano launched flames more than 1,500 feet (457 meters) into the air. The Kumani Bank eruption was less fiery but just as marvelous—creating new land sharply spotted by NASA’s satellites.

The bank’s eruptions have been recorded for over 150 years. One 1861 eruption also produced an island—albeit a smaller one, just 285 feet (87 meters) across, that eroded away by the following year. According to a NASA Earth Observatory release, the strongest known eruption occurred in 1950 and produced an island a whopping 2,300 feet (700 meters) across.

It can be hard to predict volcanic eruptions, but one thing is for certain: When another mud volcano blows its top, NASA satellites will be able to capture the aftermath.