The research team is headed by the same expert who predicted with uncanny accuracy a quake that struck Sumatra on March 28, barely three months after the December 26 temblor, one of the biggest earthquakes ever recorded.
He fears the next quakes may be as high as 7.5 and 9 respectively on the Richter scale and in the latter case, cities along much of Sumatra's west coast would be exposed to a tsunami.
"I think it would be irresponsible for those in charge of preparing people in this area to ignore the possibility that the earthquake could happen in a year," lead author John McCloskey, a professor of environmental sciences at Britain's University of Ulster, told AFP.
The study takes a fresh look at Sumatra's seismic mosaic in the light of the last two great quakes, focussing on the two biggest faultlines.
One faultline runs on the land down the western side of Sumatra, and has lateral friction, with one side trying to head north-west and the other trying to move south-east.
Stress on this so-called Sumatra fault, especially in the north-west in the region of Banda Aceh, remains high, the researchers warn.
"The threat of an earthquake of magnitude 7.0-7.5 on the Sumatra fault north of four degrees north (of the equator) has not receded," they say in the study, which appears in the British science journal Nature.
An even greater threat lies in the second faultline, the so-called Sunda Trench, a notorious seabed crack that runs about 200 kilometres to the west of Sumatra.
This area has a different and more perilous profile than the Sumatra fault, for it has vertical movement - the kind capable of creating big waves by thrusting up sections of the sea bed.
It lies in a so-called "megathrust" area, in which the Australian plate is trying to push its way under the Eurasian plate to the north-east.
The Sunda Trench has been a flashpoint of seismic activity for centuries.
Part of its northern section, at the conjunction with the tongue-shaped Burma microplate, was the epicentre for the December 26, 2004 quake, at 9.3 the second highest ever recorded.
- AFP
