ANCHORAGE, Alaska (AP) — The Latest on the earthquake in Alaska (all times local):
Scientists say the damaging Alaska earthquake and aftershocks occurred on a type of fault in which one side moves down and away from the other side.
Seismologist Lucy Jones told reporters Friday at the California Institute of Technology that the fault is within the Pacific tectonic plate that is diving under Alaska, a mechanism that produces the largest earthquakes in the U.S.
Jones says the type of damage being reported is not surprising.
She says the area in which the quake occurred has loose sediments containing lots of water and when the ground moves it creates liquefaction, or "temporary quicksand."
Jones says liquefaction can cause damage to structures because the ground moves out from beneath them.
Tim Craig, an owner of Anchorage True Value Hardware in south Anchorage, says the quake knocked hundreds of items onto the floor and caused two stockroom shelves to become unbolted from the wall and collapse.
No one was hurt. Six off-duty employees, and some customers, offered to help clean up after the earthquake hit Tuesday morning.
Craig and his wife were driving to the store when the quake hit and he says their car was bouncing.
An overhead traffic signal bobbing over their heads caused immediate concern and his wife pulled over because she was worried it would fall.
The quake knocked out numerous stoplights, snarling traffic in downtown Anchorage.
April Pearce was at her desk at work in the assessor's office in the small city of Soldotna and started filming once she realized the rumbling of the Alaska earthquake was the start of something big.
In the video, the murmurs of her colleagues can be heard as filing cabinets jostle.
Pearce says: "Holy smokes."
She says in an email later that people were gasping and panicking and called the event "spooky."
Her home escaped major damage, but some Christmas decorations fell down.
Fifteen-year-old Sadie Blake and other members of the Homer High School wrestling team were at an Anchorage school gymnasium waiting for a tournament to start when the earthquake hit.
She says the bleachers started rocking "like crazy" and then the lights went out. People ran the bleachers in the pitch dark, trying to get out.
Team chaperone Ginny Grimes says Tuesday's quake created "a gym full of screams."
By the time it was over, Sadie was still in the gym and says she started crying while hanging out in a nearby mall with her team.
Molly McCammon says was at home waiting for a work teleconference when the quake started.
She says she's lived in Alaska 45 years and called Friday's earthquake "worst earthquake I've ever been in."
McCammon had taken a tour Thursday of the Anchorage Emergency Operations Center in her role as a member of the Cook Inlet Regional Citizens Advisory Council. One of the topics was earthquake preparation.
She says: "Then it happens the next day."
McCammon says the quake reminded her how much more emergency preparation she needs to do. She plans to sign up for an emergency alert system and make sure she has an emergency kit on hand.
Back-to-back earthquakes measuring 7.0 and 5.7 rocked buildings and shattered roads Friday morning in Anchorage, sending people running into the streets and briefly triggering a warning to residents in Kodiak to flee to higher ground for fear of a tsunami.
The warning was lifted without incident a short time later. There were no immediate reports of any deaths or serious injuries.
The U.S. Geological Survey said the first and more powerful quake was centered about 7 miles (12 kilometers) north of Anchorage, Alaska's largest city, with a population of about 300,000. People ran from their offices or took cover under desks.
A large section of road near the Anchorage airport collapsed, marooning a car on a narrow island of pavement surrounded by deep chasms in the concrete. Several cars crashed at a major intersection in Wasilla, north of Anchorage, during the shaking.
Anchorage Police Chief Justin Doll said he had been told that parts of the Glenn Highway, a scenic route that runs northeast out of the city past farms, mountains and glaciers, had "completely disappeared."
The quake broke store windows, opened cracks in a two-story building downtown, disrupted electrical service and disabled traffic lights, snarling traffic. It also threw a full-grown man out of his bathtub.
All flights were halted at the airport after the quake knocked out telephones and forced the evacuation of the control tower, and the 800-mile Alaska oil pipeline was shut down while crews were sent to inspect it for damage.
Anchorage's school system canceled classes and asked parents to pick up their children while it examined buildings for gas leaks or other damage.
Jonathan Lettow was waiting with his 5-year-old daughter and other children for the school bus near their home in Wasilla when the quake struck. The children got on the ground while Lettow tried to keep them calm.
"It's one of those things where in your head, you think, 'OK, it's going to stop,' and you say that to yourself so many times in your head that finally you think, 'OK, maybe this isn't going to stop,'" he said.
Soon after the shaking stopped, the school bus pulled up and the children boarded, but the driver stopped at a bridge and refused to go across because of deep cracks in the road, Lettow said.
Former Alaska Gov. Sarah Palin tweeted that her home was damaged: "Our family is intact — house is not. I imagine that's the case for many, many others."
Officials opened an Anchorage convention center as an emergency shelter. Gov. Bill Walker issued a disaster declaration.
Cereal boxes and packages of batteries littered the floor of a grocery store, and picture frames and mirrors were knocked from living room walls.
People went back inside after the first earthquake struck, but the 5.7 aftershock about five minutes later sent them running back into the streets. A series of smaller aftershocks followed.
A tsunami warning was issued along Alaska's southern coast. Police in Kodiak, a city of 6,100 people on Kodiak Island, 250 miles (400 kilometers) south of Anchorage), warned residents to evacuate to higher ground immediately because a wave could hit within about 10 minutes.
Michael Burgy, a senior technician with the National Tsunami Warning Center in Palmer, Alaska, said the warning was automatically generated based on the quake's size and proximity to shore. Scientists monitored gauges to see if the quake generated big waves. Because there were none, they canceled the warning.
In Kenai, southwest of Anchorage, Brandon Slaton was alone at home and soaking in the bathtub when the earthquake struck. Slaton, who weighs 209 pounds, said it created a powerful back-and-forth sloshing in the bath, and before he knew it, he was thrown out of the tub by the waves.
His 120-pound mastiff panicked and tried to run down the stairs, but the house was swaying so much that the dog was thrown off its feet and into a wall and tumbled to the base of the stairs, Slaton said.
Slaton ran into his son's room after the shaking stopped and found his fish tank shattered and the fish on the floor, gasping for breath. He grabbed it and put it in another bowl.
"It was anarchy," he said. "There's no pictures left on the walls, there's no power, there's no fish tank left. Everything that's not tied down is broke."
Alaska averages 40,000 earthquakes per year, with more large quakes than the 49 other states combined. Southern Alaska has a high risk of earthquakes because the Earth's plates slide past each other under the region.
Alaska has been hit by a number of powerful quakes over 7.0 magnitude in recent decades, including a 7.9 that hit last January southeast of Kodiak Island. But it is rare for a quake this big to strike so close such a heavily populated area.
David Harper was getting some coffee at a store when the low rumble began and intensified into something that sounded "like the building was just going to fall apart." Harper ran to the exit with other patrons.
"The main thought that was going through my head as I was trying to get out the door was, 'I want this to stop,'" he said. Harper said the quake was "significant enough that the people who were outside were actively hugging each other. You could tell that it was a bad one."
On March 27, 1964, Alaska was hit by a 9.2 earthquake, the strongest recorded in U.S. history, centered about 75 miles (120 kilometers) east of Anchorage. The quake, which lasted about 4½ minutes, and the tsunami it triggered claimed about 130 lives.
AP writers Mark Thiessen in Anchorage; Becky Bohrer in Juneau; Gillian Flaccus in Portland, Ore.; and Gene Johnson in Seattle contributed.