Increased seismic activities have been recorded in the past one month in the Java-Sumatra- Andaman region of South East Asia, indicating possibility of a major disaster in the near future, according to a senior scientist at the Indian Insititute of Technology in Mumbai.

Though volcanic activities in the region had subsided after the devastating earthquake-triggere d tsunami of December 2004, more than 51 earthquakes with varying magnitutde have been recorded in the last one month, D Chandrasekharam, senior professor in the Department of Earth Sciences, IIT, told PTI on Wednesday.

This appears to be a natural cyclic process but there is a possibility of it triggering a major disaster, he said.

"Since December 25, 2006, till today morning (January 24) the entire Java-Sumatra- Andaman island subduction zone experienced more than 51 earthquakes varying in magnitude from 4.2 to 7.5 on the Richter scale," the noted earth science expert said.

"These include two major earthquakes -- 7.1 magnitude in Taiwan on December 26 and 7.5 in Molucca sea. Also 4.9 and 6.1 magnitude earthquakes were recorded in Nicobar Islands," Chandrasekharam said.

Majority of these events are associated with "thrust fault", an underground phenomenon that had caused the 2004 tsunami killing nearly 2.5 lakh people across several countries, including India.

"This only shows how active this region is seismically. Are we prepared with our tsunami warning system to alert people well in advance about any impending natural disaster?" Chandrasekharam asked.

He said perhaps a mock trial should be carried out by India to test any tsunami warning system that it is installing.

The recent earthquakes should ring an alarm bell. Tsunami warning systems should alert coastal population within 10 minutes of occurrence of any major disaster, he said.

Referring to the earthquake of 8.1 magnitude that hit the Kuril islands on January 13, he said, "The Pacific tsunami system gave warning within nine minutes of the occurrence of this earthquake and lifted the warning within 20 minutes."

Similar thing happened with regard to 7.1 magnitude earthquake in Taiwan on December 26 last year. Tsunami warning was given within 11 minutes of the earthquake and the one-meter wave triggered by it was monitored till it reached one of the Philippine islands south of Taiwan, Chandrasekharam added