What is the Warning System for a Nehalem Bay Region Tsunami?
The eruption in mid-January of an underwater volcano near the Pacific nation of Tonga triggered tsunami advisories for the U.S. West Coast. Siren alarms in a nearby coastal community sent people scrambling into cars in an effort to reach safety. Was there a danger that warranted this fear and confusion?
In Nehalem Bay communities there were questions: Why weren’t we alerted to the danger? Why didn’t we hear sirens? Tillamook County disconnected its siren system ten years ago, though a few towns have opted to keep sirens in place.
The decision to discontinue the use of sirens as tsunami warnings was based on several factors. According to Manzanita Emergency Manager, Dan Weitzel, “outdated technology, aging equipment, lack of replacement parts all led to unreliability. In addition, the sirens also sounded for fire and to mark the noon hour.” Thirty-one sirens in Tillamook County were decommissioned at the end of 2012.
What warning system is now in place for tsunamis? The size and destructive energy of the waves that reach us depends on the severity of the disturbance and where that disruption occurs. The Tonga event, 5,500 miles from our coast, is an example of a “distant” event. The warning to get off the beach comes by radio, television, phone, and county alert systems. We have hours to clear the beach.
A closer disturbance in the ocean floor, primarily in the Cascadia Subduction Zone off the coast of Oregon, means a “local” tsunami is on the way and will arrive on the North Coast in as little as 15 minutes with significant destructive force. When the ground shakes for 30 seconds or more that’s the warning to move to higher ground.
Tillamook County alerts residents via emergency notifications—whether it be text, email or voice message. Sign up now for Nixle alerts and for alerts from Tillamook Reverse 911 and review evacuation route maps published by DOGAMI.
Remember… shaking ground will be hard to miss and remains the best warning for a potentially destructive tsunami!
Contributing Writer: Marcia Silver