When a magnitude 7.7 earthquake rattled British Columbia on Saturday night, Del Norte County emergency officials sprang into action in case of a resulting tsunami in Crescent City.
The earthquake hit the Queen Charlotte Islands at 8:04 p.m. By 8:10 p.m. county emergency officials had received a message from the National Warning System, an automated telephone system used to send messages to federal, state and local governments.
Crescent City was in the clear. No watch, no warning and no advisory. The tsunami warning area on the West Coast was confined to coastal areas of British Columbia from the north tip of Vancouver Island to Cape Decision Alaska.
Just in case, county emergency services director Cindy Henderson, went to the Del Norte Sheriff’s Office to help field calls from concerned citizens, but only a handful of people called about a possible tsunami.
Things started to go haywire when the West Coast and Alaska Tsunami Warning Center, the National Weather Service’s definitive source for tsunami warnings, issued a third update on possible tsunamis.
After the third update was released at 9:10 p.m., the web application Google Alerts generated a tsunami advisory for coastal areas in California, even though there wasn’t an advisory issued for California at the time, said Henderson. Calls started pouring into the county’s 911 dispatch, Henderson said.
The situation was complicated by a glitch in the West Coast and Alaska Tsunami Warning Center’s website, which was down intermittently in the first two hours after the earthquake.
Guy Urban, a geophysicist at the tsunami warning center, said there was a configuration problem with the website. The server wasn’t ready to handle usage by 100,000 people. Urban recommended that people living in tsunami-prone areas still keep a NOAA weather radio on hand in case they cannot access the Internet.
Henderson worked with Bi-Coastal Media to spread the word that the advisory was false.
After almost an hour of trying to disprove the false advisory, Henderson went home around 10 p.m. Her stay didn’t last long. Henderson received word that Crescent City would be added to the advisory list around 10:10 p.m. and went back to the Sheriff’s Office.
During a 10:20 p.m. conference call with representatives of the National Weather Service, California Emergency Management Agency, and every coastal county in California, Henderson received word that Crescent City should expect a 30-centimeter surge around 10:54 p.m.
“We know historically that 30 centimeters will not do much to our harbor,” Henderson said Monday. Just to be safe, sheriff’s deputies, Crescent City police officers and Yurok Tribe game wardens scoped county beaches to clear them of people.
Law enforcement officials noticed a slight change in the waves while on patrol, but “if they hadn’t known to be looking for it, they wouldn’t have noticed it,” Henderson said.