JAKARTA, April 20 (Xinhua) -- Indonesia is taking steps in anticipating a massive earthquake of measuring 8.9 on the Richter scale, better known as "mega thrust", off southwest West Sumatra province that potentially triggers strong tsunamis.
Based on analysis by international and local experts, a subduction zone of the Indo Australia plate on the Mentawai Islands is still moving to find its balance.
When it happens, a big vertical fracture will rock the Sumatra Island and could generate 6-10-meter tsunami in 20-25 minutes afterward about 2-5 kilometers from the coastal line. Tsunami could occur several times.
There are 1.3 millions of people living across the west coast of West Sumatra who need more than 40 minutes to reach higher grounds.
The experts divide the Sumatra Island in imaginary segments that separate the island into several parts.
"The parts had been rocked by massive earthquakes measuring 7.9 to 8.9 on the Richter scale in 2000 to 2007, such as the 9.2- magnitude Aceh earthquake in December 2004 that triggered a strong tsunami and killed hundreds of thousand of people," said Sutopo Purwo Nugroho, head of the Data Center, Information and Public Relations at the National Agency of Disaster Management (BNPB).
However, experts have predicted that the strong earthquake could influence the subduction balance system that could trigger the 8.9-magnitude mega thrust.