Active volcano discovered at the bottom of the world's deepest lake

Video cameras mounted on autonomous underwater robots recorded volcanic cracks near a potentially active fault under Lake Baikal, Siberia.

A robot deployed at the bottom of Siberia's Lake Baikal has captured footage of cracks and deformations caused by previously unknown mud volcanoes. The robot discovered cracks left by erupted mud at depths of between 100 and 165 m in two locations – Malaya Kosa Bay and Goryachinskaya Bay – along the lake's northwest shore.

Fragments of a mud volcano photographed at a depth of 130m in Lake Baikal's Goryachinskaya Bay. (Photo: Lunina and colleagues)

Although scientists already knew Lake Baikal contained mud volcanoes, the latest discovery is near a fault zone called the Severobaikalsk , or North Baikal Fault , which lies along the lake. Signs of recent eruptions at the lake bottom could indicate an active fault line.

Mud volcanoes are surface manifestations of deeper geological processes and are formed by mud and gases erupting from below. According to Oksana Lunina, structural geologist and principal researcher at the Institute of the Earth's Crust of the Siberian Branch of the Russian Academy of Sciences (SBRAS), craters along the northwestern shore of Lake Baikal mark the The fault runs parallel to the Severobaikalsk fault and shows that this fault still exists.

Geologist Lunina said: 'In the North Baikal Depression, which is limited by this fault, strong earthquakes have occurred in the past.'

Two sites where researchers deployed robots or autonomous underwater vehicles (AUVs) , revealed layers of highly fractured rock covered by clay, soft sediments, and extrusive sediments.

According to a study published in October 2023 in the journal Doklady, in the northernmost location of Goryachinskaya Bay, where the video was filmed, craters about 130 meters deep) are filled with a "mass of mud", suggesting saw an eruption that happened recently.

Nestled in the wild Siberia is the vast Lake Baikal, shaped like a giant crescent.

This is the deepest freshwater lake in the world. The lake bottom is at a depth of up to 1,642m. At the same time, the lake has the largest freshwater reserve in the world, accounting for about 20% of the world's freshwater reserves. According to calculations, this amount of water is enough for all mankind for 40 years.