50 years ago today: Alaska rocked by record 9.2 quake

Scott's Note: Mark Furman is a fellow web producer at our sister station KVAL-TV in Eugene. He put togehter this recap of the great Alaska "Good Friday" Earthquake that hit 50 years ago today.

The earth shook for 4 1/2 minutes on March 27, 1964, at 5:36 p.m. as the largest earthquake in U.S. history tossed and bent Alaska.

The damage was costly: $113 million in 1964 dollars, more than $2.3 billion by today's standards.

PHOTOS: Aftermath of 1964 magnitude 9.2 earthquake in Alaska

The legacy of the quake is still paying scientific dividends.

"That showed us precisely how these subduction zone earthquakes and tsunamis happen," said Dr. Vicki McConnell, state geologist for Oregon. She called the earthquake a "seminal moment in understanding the dynamics of the Earth.

"Now we understand these processes," McConnell said. "How do we apply that information to making people safe?"

The 9.2 magnitude earthquake killed 15 people.

Another 113 died in tsunamis, in Alaska and elsewhere - including Oregon.

The tsunami wave took 4 hours to reach Beverly Beach near Newport.

No one knew it was coming.

"There wasn't any kind of warning in place," McConnell said.

The tsunami wave did damage from Seaside south to Gold Beach, McConnell said. The wave's power was felt as far away as South America.

Closer to the epicenter, Anchorage sustained the most severe damage to property.

About 30 blocks of dwellings and commercial buildings were damaged or destroyed in the downtown area by the earthquake.

The J.C. Penny Company building was damaged beyond repair; the Four Seasons apartment building, a new six-story structure, collapsed; and many other multistory buildings were damaged heavily.

Coastal Alaska suffered tsunami waves triggered by underwater landslides.

The water hit parts of the coast with enough force to snap trees like twigs - 80 feet above sea level.

Far from just an Alaskan event, the quake impacted the nation, the world - and the course of human scientific history.

The quake caused the Space Needle to sway more than 1,200 miles away in Seattle.

Rivers, lakes and other waterways perceptibly sloshed as far away as the coasts of Texas and Louisiana.

Water-level recorders in 47 states the entire United States except for Connecticut, Delaware and Rhode Island registered the earthquake.

The ocean's movements registered on tide gauges in Cuba and Puerto Rico.

And the U.S. Geological Survey said the quake caused the entire Earth to ring like a bell, vibrations that were among the first of their kind ever recorded by modern instruments.

USGS scientists dispatched to investigate the quake were initially baffled.

It was only after looking at the event through the emerging theory of Plate Techtonics that geologists understood that such megaquakes had happened before - and could happen again.

The 1964 quake showed "the real potential for earthquake hazards," McConnell, the Oregon geologist, said. "The one thing we can't do is we can't tell you exactly where the next one will happen."

In a film in honor of the 50th anniversary of the quake, USGS outlines how the Good Friday quake changed U.S. policy on geological hazards. | Watch a longer version of the film

USGS scientists now track seismic activity across the country and around the world.

The National Weather Service maintains 24-hour preparedness for tsunami alerts.

Building codes now aim to make new construction more resilient to earthquakes.

Because scientists agree: there will be another event like the 1964 megaquake.

And it will likely hit without warning.

"A Cascadia Subduction Zone earthquake could happen anytime - even during vacations," McConnell said. "Plan now to be ready no matter where you are."

The legacy of the 1964 quake is plain to see in Oregon, where public buildings have been evaluated for their collapse potential in the event of a 9.0 quake.

Oregon Coast communities post signs directing both residents and visitors alike to higher ground in the vent of a tsunami.

Coastal communities conduct tsunami drills to familiarize schools, businesses and first responders with evacuation routes.

And the month of March is observed as Earthquake and Tsunami Awareness Month.

The observance coincides with both the 1964 Alaska quake and the March 11, 2011, earthquake and tsunami in Japan.

"Oregon's tectonic setting is a mirror image of Japan's," says Yumei Wang, Oregon Department of Geology and Mineral Industries geotechnical engineer.

"The Tohoku earthquake and tsunami showed us how destructive a Cascadia earthquake and tsunami could be, and emphasized the need to prepare."

Longer version of USGS movie on 1964 quake