Researchers may have uncovered a better way to detect potentially deadly tsunamis before they reach land: Commercial ships equipped with GPS devices.

A new joint study by researchers at the University of Hawaii at Manoa and the National Oceanic and Atmospheric Administration’s Pacific Tsunami Warning Center say that commercial ships equipped with the right devices can accurately detect and measure tsunamis generated by earthquakes — even out in open ocean far from the earthquake’s source.

UH researcher James Foster and his colleagues found that out by happy coincidence when their research vessel Kilo Moana detected and measured the tsunami generated by a magnitude 8.8 earthquake in Maule, Chile in February 2010.

The key finding: Researchers were able to detect changes in the sea-surface height very similar to the Pacific Tsunami Warning Center predictions.

That was surprising because tsunamis in deep water are much smaller in amplitude than they are when they hit the coast.

 “Our discovery indicates that the vast fleet of commercial ships traveling the ocean each day could become a network of accurate tsunami sensors,” Foster said in a press release.

“If we could equip some fraction of the shipping fleet with high-accuracy GPS and satellite communications, we could construct a dense, low-cost tsunami sensing network that would improve our detection and predictions of tsunamis — saving lives and money,” Foster said.

Foster and co-authors estimated that this sort of ship-based system would have been able to detect the 2004 Indian Ocean tsunami within an hour, potentially saving thousands of lives.

As for next steps, researchers plan to deploy a demonstration system which will stream GPS data from one or two ships. That data will generate accurate real-time heights and confirming that this approach can achieve the accuracy needed for tsunami detection.