Large earthquakes can trigger smaller ones globally for up to a week, according to US research that could prompt changes in catastrophe modelling.

The US Geological Survey and the University of California, Berkeley, found a recent magnitude-8.6 quake in the Indian Ocean off Sumatra did little local damage but caused quakes around the world for at least seven days.

Scientists previously thought distant earthquakes did not trigger local ones, but Berkeley Professor of Earth and Planetary Science Roland Burgmann says while it is rare it does happen and should be a warning to people in seismically active regions.

The US Geological Survey says incorporating the probability of aftershocks into hazard assessment is important because a moderate aftershock can cause more damage than the main event – as happened in Christchurch in February last year, when a quake caused deaths and more damage than the September 2010 event that began the series.

The Sumatra quake on April 11 was the 10th-largest in 100 years. It triggered small quakes during the three hours the seismic waves travelled around the earth’s crust. The study says “some faults weren’t rattled enough by the seismic waves to fail immediately but were primed to break up to six days later”.

“We found a lot of big events around the world, including a 7.0 quake in Baja, California, and quakes in Indonesia and Japan that created significant local shaking,” Professor Burgmann said.

“If those quakes had been in an urban area, it could potentially have been disastrous.”