Key Takeaways
- India’s only active mud volcano dates back 23 million years to the Oligocene era
- Eruption area has expanded fivefold from 100 sqm to 500 sqm
- GSI recommends restricted public access due to eruption unpredictability
India’s only active mud volcano at Baratang in the Andaman and Nicobar Islands has been dated to the Oligocene age, approximately 23 million years old, according to Geological Survey of India officials.
The remarkable finding comes from samples collected during an October site visit, revealing lithoclasts composed of sandstone and shale from the Mithakari Group.
Significant Expansion Observed
GSI’s Deputy Director General Santanu Bhattacharjee reported substantial changes at the eruption site. “We observed four clusters of mud volcanoes with several small vents spread over 500 square meters, reaching 2 meters in height,” he said.
This represents a fivefold increase from previous records of 100 square meters and 1 meter height. All vents continuously emitted liquid mud and gases during observation.
Scientific Measurements and Observations
The surface temperature ranged between 29.3°C and 30.07°C, with pH levels of 8.0-8.3 indicating weakly alkaline mud fluid. Researchers noted an oily blackish sheen on some vent surfaces.
Bhattacharjee explained the eruption’s complex origins: “This includes diapiric movement of over-pressured surface shale layers due to loading of terrigenous sediments, rapid subsidence or lateral tectonic compression, hydrocarbon generation in deep subsurface and expulsion of fluid from depth along deep-seated fracture/fault.”
Safety Measures Implemented
The GSI has recommended restricting public access and constructing a designated viewpoint. “We’ve asked them to reinforce fencing and hazard signage regarding the unpredictability of violent mud eruptions,” Bhattacharjee stated.
The administration will maintain closure of all approaches except the designated viewpoint to ensure visitor safety while allowing observation of this unique geological phenomenon.
