WASILLA -- The 6.2-magnitude earthquake that jostled the state from Seward to Fairbanks on Thursday morning toppled shelves and broke bottles but otherwise left Alaskans unscathed.
Earthquakes of that size have killed thousands of people in places like Iran, Pakistan and China.
What's different here?
Building construction plays a role, but "there's a huge factor of luck in this as well," state seismologist Michael West said by phone from Washington, D.C.
Luck -- and depth.
Thursday's back-and-forth "strike-slip" earthquake occurred horizontally along a fault far below ground, in the tectonic plate of the Pacific Ocean that's been sliding beneath Alaska for millions of years.
It was more than 60 miles below the surface and centered just northwest of Skwentna, wild country with only a few scattered lodges.
A very different story would be emerging from Alaska had Thursday's earthquake struck on the surface and beneath a city, West said.
A 6.3 quake in 2011 killed 185 people and severely damaged Christchurch, New Zealand's second-largest city.
"What was different is that earthquake was right at the surface and it was right in town," he said.
Christchurch, like parts of Alaska, is built atop soft sediments -- think Cook Inlet mud flats or Matanuska Valley's glacial silt -- that tend to amplify shaking when earthquakes occur.
Anchorage's proximity to muskegs and mud flats probably factored into another head-scratcher about Thursday's earthquake: Why did more reports of damage and shaking pop up in Anchorage than in Mat-Su, even though the epicenter was closer to Willow?
There are a few reasons, West said. For one, there are more people in Anchorage and taller buildings that tend to generate reports when people are, say, trapped in a bathroom on the fifth floor when an earthquake hits.
In most earthquakes, West said, there are also areas in certain directions that experience strong shaking and areas in others that don't.
But another important factor is the ground itself.
Areas like Anchorage and parts of the Matanuska Valley built over sediments are "always going to respond more energetically to earthquakes" when compared to areas built over bedrock, the seismologist said. "It's not that bedrock won't shake, it will. But it doesn't tend to have that kind of runaway response."
Contact Zaz Hollander at zhollander@alaskadispatch.com.