CNN Chile | Chilean Scientists Discover Underwater Mud Volcano off the Coast of Chiloé

Eighty-six kilometers west of Chile and 1,800 meters below sea level, researchers from Universidad Andrés Bello discovered a previously unidentified structure along the Chilean continental margin: an active mud volcano. Unlike typical volcanoes, it does not expel lava or ash, but rather mixtures of sediments, water, and methane gas that rise slowly from underground.

The discovery was led by Cristián Rodrigo, an oceanographer and Ph.D. in Geophysics, and a faculty member in the Geology program at Universidad Andrés Bello. The team also included Fernanda Ruiz, Nitza Garrido, and Ximena Contardo. They named the formation the Cucao Mud Volcano, due to its proximity to the area of the same name. The results were published in the journal “Marine and Petroleum Geology,” following years of data analysis gathered during oceanographic expeditions.

The formation features a central crater, domed flanks, and a seismic reflector indicating the presence of gas hydrates and free gas — typical signs of active mud volcanoes.

“We used high-resolution bathymetric technology and seismic profiles to visualize the shape of the seafloor and what lies beneath it,” said Cristián Rodrigo, explaining how they managed to detect the volcano underwater.

How Did the Mud Volcano Form?

The expert explained that the mud volcano formed “through successive eruptions of mud, where each new layer was deposited over the previous one, gradually creating the circular structure and crater we see today.”

Rodrigo added, “This area is part of an active tectonic margin, where the Nazca Plate is subducting beneath the South American Plate. This compression creates faults that allow fluids and gases to rise. Additionally, the sediment accumulated off the island promotes the formation of gas hydrates, which release methane when destabilized.”

Finally, the academic clarified that “there is no risk to the population or to maritime navigation. The activity occurs at great depth and progresses slowly, but it’s important to monitor it because these systems can be reactivated by changes in pressure, temperature, or seismic activity.”

CNN Chile | Científicos chilenos hallan volcán de lodo bajo el mar en Chiloé