Commercial ships on Earth's oceans could provide a cheap and easy way to track propagating tsunamis.
Current warning systems rely on sparse, expensive buoys and underwater sensors that track a wave once it has been triggered by an earthquake. James Foster at the University of Hawaii at Manoa in Honolulu and his team examined Global Positioning System (GPS) data from a research vessel (pictured) that was heading from Hawaii to Guam in February 2010 when an underwater earthquake occurred off the coast of Chile. Filtering the data on the basis of tsunami models allowed the researchers to differentiate between choppy seas and changes in ocean surface height due to a tsunami. The team detected a roughly 10-centimetre rise as the tsunami passed, and estimated wave speed and arrival time.
Although data from a single ship could be prone to false positives, recruiting thousands of ships could overcome this problem, the authors suggest.
Geophys. Res. Lett. http://dx.doi.org/10.1029/2012GL051367 (2012)