Tsunami alert system for U.S. coastline faulted

WASHINGTON – A detection system that was expanded following an Indian Ocean tsunami that killed 230,000 people has experienced significant outages and can no longer be relied on to detect the giant waves as they approach the U.S. coastline, a new report finds.

The system, known as DART, or Deep-ocean Assessment and Reporting of Tsunamis, was expanded from six deep-ocean buoy stations to 39 in the months following the massive 2004 earthquake off Indonesia that spawned killer waves. Though there are DART buoys in the Atlantic and the Caribbean, most of them are located around the Pacific Ocean’s “Ring of Fire” to give advance warning to Washington, Oregon, California and Alaska, where a tsunami landfall is thought more likely.

But at any given time, 30 percent or more of the buoys have been inoperable, according to a recent report from the National Research Council.

The Cascade subduction zone where tectonic plates collide off the coast of Washington, Oregon and northern California is overdue for a mega-quake that could easily reach a magnitude of 9.0 on the Richter scale. The quake could trigger a tsunami that by some estimates could be 90 feet tall and arrive on the Northwest coast in minutes.