Ash from volcanic eruption in Mt Merapi may hit Indian region

Activity monitored by the Merapi Volcanological Observatory has predicted a cataclysmic explosion that could wipe out everything in its path and, therefore, the Aviation industry has to keep a close watch on this volcano.

Lava flow is not a major concern but this strato volcano is characteristic of blowing tones of ash plumes and India could be on its fire line, said Dr D Chandrasekharam, Professor of the Department of Earth Sciences, IIT-B and a Board of Director, International Geothermal Association told PTI today.

"A cataclysmic explosion or eruption is when the mountain basically explodes. Previous world cataclysmic eruptions were Mount Vesuvious that buried the Roman towns of Pompeii and Herculaneum, St Helens in Washington, Hekla in Iceland, and the well documented volcano of Pinatubo in Philippines," he said.

Merapi, one of Indonesia's most active volcanoes, dominates the landscape immediately north of the city of Yogyakarta in one of the world's most densely populated areas.
"According to the Merapi Volcanological observatory, the inflation rate of the surface of the volcano increased from 0.6 cm/day on 20th October to 42 cm/day on 24th October, just before the eruption," Chandrasekharam said.

"When the seismic signals are pointing towards a cataclysmic volcanic event, it is but natural to expect a major earthquake around this region which is a major active subduction area in the Indian Ocean," Chandrasekharam said.

"This is what exactly happened the day before when subducting Indian plate below the Sumatra trench slipped to fill the gap created by the volcanic eruption. This may be just the beginning if the Merapi Seismological prediction are true," he said.

Monday's earthquake in southern Sumatra of 7.5 magnitude did create fear not only for the Indonesian Islands but also to Andaman Nicobar group of Islands. This major tremor was followed by 13 aftershocks of magnitiude of 4.7 to 6.1 indicating adjustment by the sinking Indian plate.

"The focus started shifting from the depth of 14 km to 29 km, typical of sinking oceanic slab below a subduction zone. It appears that the volcanic activity has preceded by the earthquake activity. Such phenomena is usually restricted to the region around the volcanic activity as is commonly observed in other volcanic regions in the world like Mt Etna and Stromboli in Italy," Chandrasekharam said.

He also said that India is flanked by most active volcanoes -- The Piton de La Fournaise of the Reunion island in the Indian Ocean and a chain of active volcanoes over the Indonesian islands of Sumatra and Java, besides the Barren island volcano in the Andaman Sea off Port Blair, Andaman Nocobar islands.