Tsunami warning canceled after ‘major’ 7.0 magnitude earthquake hits off Humboldt County coast

The National Weather Service canceled a tsunami warning hours after a powerful earthquake nearly 300 miles north shook parts of Santa Cruz County on Thursday morning. The weather service had forecast a tsunami to follow, hitting as far south as Davenport, but had canceled the warning as of noon. 

The U.S. Geological Survey reports that the earthquake, which hit off the coast of Humboldt County, registered a 7.0 magnitude at 10:44 a.m. By 10:51 a.m., smartphones throughout Santa Cruz County buzzed with tsunami warnings. 

In the 11 o’clock hour, Braden Murdoch, a meteorologist with the National Weather Service Bay Area, told Lookout that the tsunami surge was expected to reach San Francisco around noon.

During a news conference Thursday morning, Christine Goulet, director of the USGS Earthquake Science Center, called it a “major earthquake” and said that aftershocks were expected. Goulet said there was 6% chance that any aftershock would have registered greater than a 6.0 magnitude, while the likelihood for aftershocks of 5.0 magnitude or lower stood at 40%. By contrast, the 1989 Loma Prieta earthquake registered a 6.9 on the Richter scale. 

The warning was called off after offshore buoys failed to detect tsunami activity, District 3 county supervisor Justin Cummings wrote in an email.

Although the tsunami warning had been canceled, the county sent out text alerts shortly after noon urging residents to avoid the coast. 

At the Santa Cruz Harbor around 11:30 a.m. Thursday, officials said they were preparing for tsunami activity. “As of right now we were informed that there was an earthquake, that’s all we know. We’re not exactly sure what that’s going to look like for the harbor,” Deputy Harbormaster Parker Guy told Lookout. “We’ve been advised that there is going to be tsunami activity in the next 30-40 minutes. We’re not sure how big it’s going to be, so we’re just advising everyone to go to high ground right now.”

Santa Cruz City Schools spokesperson Sam Rolens said district officials checked with the National Weather Service and with City of Santa Cruz staff to ensure that the tsunami warning didn’t pose any danger. All of the school district’s campuses are above sea level. 

“We got assurances that the affected area, even out of an abundance of caution, ended in Davenport, once we had that confirmation we sent it out as soon as possible,” he said. 

Santa Cruz City Schools sent out a text message and an email to parents and other members of the district community letting them know that Santa Cruz was not within the area first identified in the tsunami warning. “All campuses safe, normal school day continuing,” the text read. 

In Davenport, Pacific Elementary Superintendent Eric Gross said he received “a gazillion” phone calls from concerned families after the earthquake. Families picked up seven students out of concerns for the tsunami warning. 

“I’m feeling pretty confident that we won’t have to do anything drastic, and I feel like we have a plan that is practical and fast,” said Gross. “I’ve got a volunteer parent watching the ocean for me.” 

He said staff were staying calm and classes were continuing, but they’re keeping a close eye on the ocean. The school is located on a cliff that’s 259 feet above sea level, much higher than an estimate for the waves he read: 100 feet. In that case, the waves would hit the cliffside rather than climbing up a gradual slope, in order to affect the school. 

“It would have to be an historically high thing, like the biggest tsunami ever,” he said. “And therefore, I don’t think we’re in danger. But of course, you can’t sort of gamble and have a bunch of kids.” 

Gross said if they see a tsunami, which they can observe from far off the coastline, they’ll walk the kids up a steep hill behind the school.

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