A 5.4 magnitude earthquake shook Southcentral Alaska on Monday morning. While there were no reports of serious damage or injuries, nerves were rattled, dishes fell and drinks spilled.
The quake hit at 11:28 a.m. and was centered 24 miles northwest of Willow. Lasting several seconds, the temblor could be felt as far away as Homer and Fairbanks, a stretch of 400 miles.
The earthquake was "pretty deep," said Cindi Preller, geologist with the West Coast and Alaska Tsunami Warning Center. It originated 32 miles below the Earth's surface.
"I almost had a customer run out the door," said waitress Jolene Pate, who was waiting tables at a diner about 30 miles north of the epicenter. "The hanging lamp shades were swinging."
Sensors initially logged a magnitude 5.7, but as more data came in, seismologists downgraded it to 5.4. Several brief aftershocks continued into the afternoon; one registered as high as 4.0.
A dispatcher at the Alaska State Troopers post in Talkeetna said they'd received no reports of damage.
"The most reported was some objects moved around a shelf in Wasilla," said Paul Whitmore, director of the tsunami warning center.
Ola Williams, who runs the Alaska Dream Espresso stand in Willow at the corner of the Parks Highway and Willow-Fishhook Road, was about as near the epicenter of the quake as it gets. She was in the middle of making an iced Americano when the earthquake hit.
"I was right up front, starting to make a drink for a customer," she said. "There was a big noise. ... They said, 'Well, what's that?' I told him we're having an earthquake. Then it really started shaking."
Syrup bottles did a little tap dance on the shelf and a box of ice cream cones tumbled off the top of the refrigerator but that was the extent of the damage.
Sarah Stearns in Talkeetna said it was the strongest she's felt in years. Her husband and 10-year-old daughter ran outside and stood away from the trees, she said.
"I stayed inside and rode it out. I'm from California."
The earthquake was 170 miles west of the 800-mile trans-Alaska oil pipeline and operations were not affected, Katie Pesznecker, a spokeswoman for Alyeska Pipeline Service Co., told the Associated Press. The pipeline, which carries about 715,000 barrels of crude daily, is designed to withstand magnitudes as high as 8.5, she said.
Southcentral Alaska usually gets one or two earthquakes this size a year, Whitmore said. Many more are recorded, but most are too small or too remote to be felt. The last one that measured stronger was a 5.8 in southern Alaska on Jan. 24.
The Monday tremor originated from the Denali fault line, the same line that produced the big quake of 2002, which measured 7.9 in magnitude. While it is active with lots of small quakes a year, it is not typically thought to produce big rattlers, Preller said.
Geologists didn't know Monday night if the quake was caused by the friction of two plates rubbing against each other, called a strike-slip, like the San Andreas Fault near San Francisco, or if it was one giant hunk of earth sliding under another giant hunk of earth, called subduction. Both kinds of quakes occur in the area where this one was, Preller said.
A tectonic plate reaching from the tip of the Aleutians to Skwentna has been submerging itself under the rest of Alaska for millions of years, Preller said.
"It's really, really exciting geology here," she said.
Stephanie Komarnitsky contributed to this story from Wasilla.