NASA has released images of a vanishing “ghost island” in the Caspian Sea captured by its satellites.

Why It Matters

The Kumani Bank mud volcano, also known as Chigil-Deniz, a feature located roughly 15 miles off the eastern coast of Azerbaijan, erupted in early 2023, resulting in the phenomenon.

Mud volcanoes, though not fully understood, occur in areas where subsurface layers of fluidized sediments, like silt and clay, are pressurized by tectonic activity, such as near the boundaries of the Earth’s crustal plates or by the buildup of hydrocarbon gases. This pressurized sediment is pushed upward, erupting at the surface to create mounds of mud. Their eruptions can present danger, sometimes expelling flammable gasses and even pillars of flame.

NASA said that “these features may not be unique to this planet; scientists think that some muddy mounds in the northern lowlands of Mars may have formed when gas- and liquid-rich sediments spewed out to the surface.”

What To Know

A series of images from NASA‘s Landsat 8 and Landsat 9 satellites have captured the island’s appearance in the sea and its near-complete disappearance by the end of the following year.

According to NASA, the leftmost image shows the volcano’s crest below the surface. In the center image, captured in 2023, an island emerged with a sediment plume trailing away. In the final image taken December 25, 2024, a significantly reduced section of Kumani Bank was visible above the water.

This is not the first time Kumani Bank—the volcano whose eruption created the transient island—has spawned such a feature.

In May 1861, an event created an island measuring just 87 meters (285 feet) across and rising 3.5 meters (11.5 feet) above the water. It eroded by early 1862. The most powerful eruption occurred in 1950, forming an island 700 meters (2,300 feet) wide and 6 meters (20 feet) high, per NASA.

Azerbaijan stands out for its exceptionally high concentration of mud volcanoes, NASA said. The country is situated where the Arabian and Eurasian tectonic plates collide.

What People Are Saying

University of Adelaide geologist Mark Tingay, at a seminar for the Geological Society of Australia: Mud volcanoes are “weird and wonderful features that remain largely understudied and little understood.”

Stanford University Professor Eric Dunham said: “Volcanoes are complicated and there is currently no universally applicable means of predicting eruption.”

Do you have a story we should be covering? Do you have any questions about this article? Contact [email protected]