• GPS;
  • sea surface height

[1] Accurate and rapid detection and assessment of tsunamis is critical for effective mitigation. We show here that a modest ∼10 cm tsunami from the M8.8 27 Feb 2010 Maule, Chile earthquake was detected by kinematic Global Positions System (GPS) solutions from a ship underway in the open ocean - the first time shipboard tsunami detection has been achieved. Our results illustrate how the commercial shipping fleet represents a vast infrastructure of potential open ocean GPS platforms on shipping lanes that provide extremely good spatial coverage around most tsunamigenic source regions. Given the affordability of geodetic GPS systems, and ever-improving satellite communications, it would be possible to equip a significant portion of the shipping fleet with real-time-streamed GPS systems and create a cost-effective tsunami monitoring network with denser and more distributed coverage. We project that such a system would have detected the 2004 Indian Ocean tsunami in less than an hour.