Friday, January 28 2005 18:18 Hrs (IST) - World Time -

Mumbai: Unusual events "unheard of in the history of seismology" have been recorded in Andaman and Nicobar islands, with more than 120 such events being recorded in the last one month, according to seismologists.

The seismology department of Bhabha Atomic Research Centre (BARC) and the Earth Sciences Department of Indian Institute of Technology in Mumbai have recorded over 120 such unusual events in the Islands following the December 26 major earth quake measuring 8.9 on the Richter scale which triggered tsunamis that wrecked havoc in several parts of the country.

Of these events recorded at BARC's Gouribidnur station in Karnataka, at least over 33 events were above 5 on the Richter scale, they said, adding "this is unusual and alarming as large amount of energy is being released so frequently."

Eleven events with surface wave of magnitude 5, indicating large amount of energy close to Nicobar Islands was also recorded, the seismologists said.

"Since yesterday, 16 events which range from 5.2 to 5.8 on the Richter scale have been recorded," they said.

"Whether these events are foreshocks or after shocks - it is not clear, and has to be taken up seriously and the data analysed as fast as possible," the scientists said.

"Both 'strike slip' and 'dip slip' are taking place simultaneously and these factors have to be taken very seriously both by scientists and authorities," they added.