(Photo: Wikimedia Commons/NSF/USAP photo by Steve Clabuesch)
The autonomous video cameras mounted in an underwater robot captured cracks on the shores of Lake Baikal. The robot was deployed at the bottom of Siberia's lake last summer.
Autonomous Robot Captures Potential Active Fault in Lake Baikal
In the study, researchers used the data captured by a robot or autonomous underwater vehicle (AUV) deployed in two sites. The robot found scars from mud eruptions at two spots on the lake's northwest shore, Malaya Kosa Bay and Goryachinskaya Bay, at depths of 340 to 540 feet (100 to 165 meters).
The most recent discovery is uncomfortably close to a fault zone known as the Severobaikalsk, or North Baikal fault, which straddles the lakeshore. Scientists already knew that Lake Baikal hosted mud volcanoes. Recent eruptions at the lake's bottom may indicate that the fault is preparing for an earthquake.
The film depicts the torn and forced-up rock strata caused by mud and gas-saturated fluid eruptions. As the researchers observed in the study, boulders seemed to have been "squeezed out" from underneath, and the dusting of silt and clay on top appeared disordered and porous.
They also discovered hundreds of tiny, cone-shaped craters a little bit deeper in Goryachinskaya Bay, at a depth of about 525 feet (160 meters). The researchers found that brittle bottom deformations accompany them everywhere. White sponge colonies were housed on surrounding hard surfaces, and the vents, measuring 2 inches (5 centimeters) in height and diameter, were brimming with amphipods and gastropods.
The researchers noted that "it became apparent that the entire steep slope was densely covered with mud volcanoes" when the AUV descended to somewhat shallower depths. Because volcanoes typically don't form at such shallow depths, e they need tremendous temperatures and pressures to rush.
The discovery of active cracks wasn't a total surprise because the area had had strong earthquakes.
"In the North Baikal depression, which is limited by this fault, there have been strong earthquakes in the past," said Oksana Lunina, a structural geologist and senior researcher at the Institute of the Earth's Crust in the Siberian Branch of the Russian Academy of Sciences (SBRAS) who participated in the discovery, in a statement.
The fault may be active, as indicated by craters that "mark cracks that run parallel to the Severobaikalsk fault" along the northwest side of Lake Baikal.
Lunina, however, acknowledged that there may be another mechanism for their findings. She added that slurries may rise and erupt through Lake Baikal's bottom due to minor movements and earthquakes in the Severobaikalsk fault. However, it is unlikely that these mud and gas fountains will alter the depths of the lake.
"It must be a part of the Baikal ecosystem," she added.
What Are Mud Volcanoes?
A mud volcano is a mud mound that rises through the underlying sediments. Usually shallow, the craters can occasionally erupt. These eruptions easily erode the cones and constantly rebuild themes.
Some mud volcanoes are formed by hot spring activity, in which boiling mud is formed by the chemical reaction of enormous volumes of gas and small amounts of water with the surrounding rocks.
RELATED ARTICLE: How Do Volcanoes Erupt, and How Scientists Study and Predict These Eruptions
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