Earthquake triggered volcano eruption on Andaman's island on September 20: Expert

India's lone progressive volcano located connected the uninhabited Barren Island successful Andaman Sea erupted connected Sept 20, presenting a ocular extravaganza uncommon for southbound Asia. The occurrence was successful information the effect of an earthquake of magnitude 4.2 that deed the portion 2 days earlier the event.Though the eruption was insignificant with nary contiguous hazard to quality settlements successful Indonesian archipelago, the occurrence - 4th since 1991 - can't beryllium overlooked arsenic the land lies implicit a responsibility that moved, causing the Dec 2004 tsunami. The fault's coordinates autumn connected the aforesaid latitude arsenic the Barren Island volcano and successful the vicinity of the longitude of the quake that made the magma enclosure apt for "pre-mature magmatic eruption", said O P Mishra, director, National Centre for Seismology. Such episodic volcanic eruption witnessed successful 1991, '04 & '05: Official O P Mishra said it was "earthquake shaking intensity" successful magma enclosure of Barren volcano that erupted this month. Barren Island is astir circular with a diameter of astir 3.2km wherever the volcano rises astir 2km supra the oversea floor. Its mean tallness is 300m supra mean oversea level. "Andaman-Nicobar Island is located successful the subduction analyzable consisting of the down going Indian sheet intruding to the mantle of the overriding Sunda Plate wherever continuous earthquakes of mean to beardown strengths utilized to hap too the micro seismicity successful the area," said Mishra.

There are 2 magma related lava volcanoes located on progressive West Andaman Fault. Though Barren Volcano has been progressive for years, the eruption is intermittent and sporadic arsenic and erstwhile magma enclosure astatine the depths of 18-20km are activated. Lava and magmatic eruptions hap from clip to clip owed to disturbance of the magma enclosure by seismic vigor generated from beardown to mean earthquakes that upwelled lavas to the aboveground done volcanic vents.

"This benignant of episodic volcanic eruption was witnessed successful 1991, 2004, 2005, and present successful 2025," said Mishra.He said the lava and magma persists and remains successful the moving authorities and is pushed upward erstwhile the 'earthquake shaking' tries to bring the blistery materials to the aboveground done cracks and fractures widened by the continuous seismically progressive cycle. The different volcano successful the region, Narcondam, is, however, dormant astatine present.