Updated

Glitches were reported in Alaska's tsunami warning system after Thursday evening's 7.3 earthquake in the Aleutian chain, causing some anxiety and bewilderment among residents.

State Department of Homeland Security spokesman Jeremy Zidek said Friday that tsunami warning messages were sent late via the emergency alert system to TV and radio stations, about the same time the warning was being canceled.

The Kenai Peninsula Borough reported its sirens, tied to a weather radio system, only went off when the alert was canceled. Normally, there's no siren when a warning is canceled, emergency management director Eric Mohrmann said.

"It's unfortunate it occurred" that way, he said Friday. "It's not a perfect system, that's for sure."

The reason for the glitches wasn't immediately clear, though Zidek said the state does not rely on just one system to alert communities to possible dangers. For example, he said officials also send emails and make calls, alerting communities to possible impending dangers. In all, 14 communities were notified Thursday, he said. Mohrmann said he learned of the tsunami warning by email.

It's not the only emergency management communication problem for the state this week.

Alaska State Troopers Capt. Barry Wilson told the Anchorage Daily News the agency is investigating glitches in this week's Amber Alert, including breaks in audio for some radio and TV listeners. There were also problems with television text scrolls that either didn't appear or moved too fast, and not everyone who signed up for Amber Alert email and text message alerts received them.

The tsunami warning glitches were cast more as the exception than the rule in a state where earthquakes are common occurrences.

Thursday's quake, a magnitude 7.3, according to the Alaska Earthquake Information Center, shook a huge section of Alaska's Aleutian Islands. Centered about 122 miles east of Atka and about 1,200 miles southwest of Anchorage, it was jarring enough to send residents of some small coastal towns, such as Unalaska, to higher ground. There were no immediate reports of damage.

It hit just after 7 p.m. Thursday.

Unalaska's mayor, Shirley Marquardt, was at the airport. The shaking wasn't violent but it lasted "long enough." Officials decided to evacuate the low-lying city as a precaution. This time of year, the community is bustling. The hotel, which is built around sea level, like many other buildings in town, was full, she said.

"We stand to lose everything in a tsunami," Marquardt said.

Unalaska City Manager Chris Hladick estimated that thousands of people evacuated to higher ground until they received the all-clear. He said the process ran smoothly, with sirens blaring and officials going through neighborhoods to rouse residents. Ships were sent out of the harbor.

Atka resident Rodney Jones said the shaking he felt lasted about 20 seconds and was "just a little rumbly."

He said it appeared all of the town's 61 residents moved to higher ground upon hearing the tsunami warning, which he heard issued over CB radio. Townspeople gathered on a high hill for about an hour, near the city's new water tank.

During their wait for the all-clear signal, a priest with the town's Russian Orthodox Church recited prayers, Jones said.

___

Associated Press writer Mark Thiessen contributed from Anchorage.

Becky Bohrer can be reached at http://www.twitter.com/bbohrer .