Alaska earthquakes - July 2015

"....Perhaps the building codes in Alaska have improved, ..."

They actually have improved quite a bit. All buildings in a regulated area in Alaska are now built to seismic zone standards (Fairbanks may be a lower standard than Los Anchorage, can't recall for sure) and there are many mundane improvements as part of that:

- More "flex joints" built into concrete buildings;
- More analysis on structural steel design
- (Near and dear to my heart as I spent years putting these in as a younger fella) All piping now has sway braces so that it stays in place during a quake

One of the more innovative ideas was used on a major building in Anchorage (one of the last ones that I'm familiar with) from the mid-90's: that building rests on a 24" (IIRC) layer of sand and has a similar sized zone on the sides...the intent being that the sand acts as a "lube plate" between the moving earth and the building structure. We'll see how it works on the next 8 - 9+ quake.

In 1964, we lived in Kitimat, down the coast a ways from the epicenter. We did feel it there, but it wasn't sever. We also had a mini tsunami at the end of Douglas channel, but little damage was done. That's not like what happened at Port Alberni! That place got struck bad with the tsunami

Must have been a slow news day for a 6.4 quake in Alaska to get TV coverage. Sue, I just realized the Good Friday earthquake was the day before you turned 6 years old. The 9.2 quake in 1964, made a real mess out of lots of south central Alaska, especially Anchorage over towards Valdez. They moved Valdez to it's current location on deeper water to prevent future tsunami damage. The old location was at the head of the bay, in shallow water.

Perhaps the building codes in Alaska have improved, but most of the people I know that live in the Anchorage area are no better prepared for a disaster than they were in 1964. Much of the geography of Alaska was formed from being part of the Ring of Fire, with the accompanying volcanoes, earthquakes, etc. most of the valleys north of Mount McKinley, the Minto Flats and the Tanana valley toward Fairbanks were formed from long ago quakes. Small quakes are very common throughout most of Alaska. Very few cause any serious damage, but one day another 9+ quake will hit the state.

sue.t wrote:
I lived in Beaver Creek, Yukon when the BIG one - magnitude 9.5 - hit Valdez on March 28, 1964. Seven months after the earthquake we visited Valdez and Anchorage. The amount of damage was amazing. The whole town of Valdez was moved because of it.

We also had some effects in our yard at Beaver Creek from that quake. My parents wouldn't let me play in the yard until the crack in the ground was repaired. But our home was okay and nothing else was damaged.

Four things stick in my mind about the '64 quake (I was much younger at the time, obviously) as I was growing up in Los Anchorage:

1) Family lived in a log cabin at the time with logs (in lieu of planking) for the first 3 feet or so of the roof; we lost 2 logs off that portion;
2) Some months after, I was with my uncle in Kodiak and asked him why that big boat was sitting so high on the ground on the hillside.....
3) "Town" of Portage sunk;
4) Koslosky's store and my dad's rental house both were broken in half and fell about 15 feet.

We were camped at the top of the hill, between the highway and the cliff, overlooking Homer, when this latest one hit. According to the experts, the epicenter was in sight, directly across the bay. I had just stepped out of the motorhome, and walked to a garbage barrel a few feet away. The barrel was up against a small enclosure, surrounded by a 6' high stockade fence. I was mindlessly tearing a cardboard carton apart when I had the strange feeling of somebody pushing me skyward, about half a foot or so, then slowly lowering me down. Like if you were standing in the back of a truck when the driver slowly crossed a big speed bump. As I though WTH was that? I looked up and saw the entire fenced enclosure slowly dancing like a flag in a light breeze. It was all over in a few seconds. I open the door to the camper and found my wife with a death grip on the corner of the dinette. She was a bit pale and said it was pretty scary, and she thought that the rig was going over. I've been through a few others and they all seemed to last a lot longer, or were a lot more violent, this one was a few interesting seconds.

I was living on the Kenai when the '64 quake hit. It knocked out all the radio and TV stations and the only thing we could pick up was KGO San Francisco on the car radio. They broke into regular programming to announce the quake in Alaska, issue Tsunami warnings and tell us that early reports had the entire Kenai Peninsula under 8 ft of water. Kind of surreal to hear the radio announce that you're dead.

I lived in Beaver Creek, Yukon when the BIG one - magnitude 9.5 - hit Valdez on March 28, 1964. Seven months after the earthquake we visited Valdez and Anchorage. The amount of damage was amazing. The whole town of Valdez was moved because of it.

We also had some effects in our yard at Beaver Creek from that quake. My parents wouldn't let me play in the yard until the crack in the ground was repaired. But our home was okay and nothing else was damaged.

We're sitting in Valdez and enjoyed the ride. There wasn't any doubt about what it was when it struck. No tsunami warnings issued. Quake epicenter was just south of Mt. Redoubt, the volcano south of Anchorage on the west side of Cook Inlet that erupted in 2009 and blanketed the area intermittently in ash.

Guam had one also. Maybe the pacific rim is finally going to create that ocean front property in Arizona.

Now the big worry, what's for dessert.

A friend near Willow (north of Anchorage) didn't feel it.

Yet, one of the reality TV shows filming near Girdwood (east of Anchorage) had to stop filming due to their shaking - it will be interesting to see if they include that event in the final cut.