From the KVAL.com archives
An earthquake Sept. 29, 2009, sent shockwaves around the world and waves that forecasters feared might hit Oregon's shores, triggering a Tsunami Advisory for the Oregon Coast.
According to the Tsunami Warning Center, an Advisory means there is a threat of a potential tsunami that may produce small currents dangerous to those in or near the water.
The next level of alert is a Watch. A Watch means a tsunami could later impact an area. They are usually issued based on seismic information and do not mean a tsunami is underway.
A Warning is issued when a tsunami is imminent. Warnings mean widespread, dangerous coastal flooding is possible. The state's tsunami evacuation area in Lane County includes downtown Florence and everywhere along the Siuslaw River.
In some emergencies you will hear a broadcast over the radio or TV, but not in the case of the Sept. 29, 2009, quake.
KVAL News called the Emergency Alert System to find out why. Bill Schneider, a Science and Operations Officer, said Tuesday's Tsunami Advisory did not reach the Emergency Alert System because there was no immediate threat to life and property and no damage was expected. Had that Advisory been raised to a Watch or Warning, you would have heard the broadcast.
You've probably heard the tests of those loud, tsunami sirens. It is up to local community emergency officials to decide whether or not to use those.