Thread by @AKearthquake

Five years ago, on the 50th anniversary of the Good Friday Earthquake, this account was new and had fewer than 100 followers. We tweeted a 50-years-later play-by-play of the 1964 earthquake and tsunami as it happened, more or less into the void. Here it is again, slightly edited.

Fifty-five years ago today, the M9.2 Great Alaska Earthquake—the second largest ever recorded—began right about now. Many survivors remember their TV screens going blank during Fireball XL5

Over about four or five minutes, the earth ruptured from Prince William Sound to Kodiak Island.

An airman stationed at Elmendorf AFB: "We ran out of the building and hung on to the wire mesh fence across the street. The road looked like waves in the ocean. All of the air police trucks looked like they were dancing as they were bouncing up and down.” bit.ly/williamziesemer

In some communities, landslide-generated tsunamis struck before the shaking ended. This tire-impaling board shows the power of the Whittier tsunami.

The hardest-hit community, proportionately, was Chenega. About a third of the village's 70 people died, including many elders. Only the school and one house remained. “Within five minutes Chenega was gone, and no one even knew about it."
diva.sfsu.edu/collections/sf…

The Valdez dock sank into the harbor along with 98 million cubic yards of coastline. Waves tossed the 400' steamboat Chena like a toy. 28 adults and children vanished with the dock; three men died on board the Chena.

The Valdez and Chenega tragedies accounted for about half of all deaths in Alaska. At about the same time, 40' waves devastated Whittier, killing 13.

20-30' waves crossed and recrossed Kenai Lake as stream deltas collapsed. 150 yards of the Kenai River reportedly ran backwards. In Seattle, 1300 miles from the epicenter, the Space Needle swayed noticeably.

In Seward, burning waves carried a 75-ton locomotive 300 feet as 14 oil tanks and 40 railroad cars went up in flames.

Much of Anchorage lay in ruins.

This was just the beginning. Waves from the tectonic tsunami had yet to arrive.

Waves reached Kodiak communities anywhere from 20-45 minutes after the quake. In Kaguyak, as the first wave arrived, a man radioed a tsunami warning to Old Harbor, saving lives throughout the Kodiak region.

At 6:24, the first wave struck Old Harbor at low tide, doing little damage. Larger waves would come in the night.

Excellent short video about the tsunami in Old Harbor. "There were popping up and down, the houses...buildings bumping buildings...some of our homes drifted out to sea..."

The death toll points out the danger of local, landslide-generated tsunamis. Landslide tsunamis killed 81. The tectonic tsunami, generated by seafloor movement along the fault rupture, arrived later and killed 25 in Alaska.

The largest recorded wave, from a landslide tsunami, was 78' high with a run-up of 170', in Shoup Bay near Valdez. Harry Henderson was washed away along with his cabin.

Nine people were killed by the earthquake itself, which seems impossibly low from photos of the aftermath. Critically, most people were in their homes, which tended to be small, wood-frame structures.

The Four Seasons apartments in Anchorage. Note the apparently intact wood-frame buildings behind it.

There's going to be a bit of a break here while we wait for more tsunami waves. Which is why you don't go check on your boat in a situation like this.

Nearly three and a half hours after the earthquake, the fourth and largest wave struck Kaguyak. Every house was washed off the spit, killing either two or three, depending on the report. The village was abandoned. alutiiqmuseum.org/word-of-the-we…

In Afognak, also in the Kodiak region, the first wave arrived at 6:15pm and the largest at 9:27pm. That wave destroyed most buildings along with two bridges. All residents survived, but the village was moved to Port Lions.

The tsunami reached Vancouver Island four hours after the earthquake. British Columbia coastal communities sustained $10 million in damage, but there were no deaths.

Beginning around 9:50pm, a series of tsunami waves hit Port Alberni, British Columbia. Here's a Super-8 film of the aftermath, taken by an insurance adjuster.

Five hours after the earthquake, more waves arrive in Seward at high tide, flooding the causeway and killing three. This brought Seward’s death toll to 12. In Valdez, the entire waterfront was burning and would burn for two weeks.

Meanwhile the tsunami was still moving south along the West Coast. Four campers died when it came ashore at Newport, Oregon.

The fourth and largest wave finally reached Old Harbor at around 11pm, washing away 30 homes and damaging the remaining 8 beyond repair.

The first of a series of waves reached Crescent City, California at 11:19pm. The first caused little damage. The third and fourth were much larger, running as far as 500 yards inland and killing 11.

The tsunami continued on and was eventually observed in Antarctica, but the deaths in Crescent City were the last ones.

The 1964 earthquake was enormously important to Alaska's development as a state as well as to our understanding of plate tectonics and earthquake hazards. But first and foremost, it was a life-changing disaster for many Alaskans.

The death toll was numerically low but proportionately high in some small communities--and some villages ceased to exist in their old locations. It's important to remember those losses, to understand what we are protecting ourselves from as we work to make Alaska more resilient.

Thank you for reading. We promise to have new content for the sixtieth anniversary.