These Aftershocks tho...

Eric Stoltz

Eric Stoltz

Line Up and Wait
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We're at 240+ aftershocks from the 7.2 here in PANC. Got my butt awoken by my roomie hollerin, the wife leaping outta bed, and everything on a shelf flying off at us. Was fun trying to stand for the 25 seconds of +/- .5g's, and +/- 45cm of vertical travel as the earth wiggled. We did throw on warm clothes and escaped right as the first big aftershock shook. We're okay, and the mess is all cleaned up.

Not one to get all fired up during exciting times, but these aftershocks keep my adrenaline pumping and we're getting exhausted. The first big one is the most impressive.

But, because this is a pilot board, my flight was canceled because half the pilots can't drive to the airport since the roads are kinda jacked up. And, there are some spectacular pics being made by pilots in super-duper-cubs and choppahs. Plus, the tower guys had to escape for a bit. The FAA made a ground stop to PANC for a bit to check the infrastructure of the airport. Jet fuel tanks and pipes are good. It's all good.

Any AK POA's need me to check on their airplane at PALH? I'll pet it and provide some comfort and let it know that everything will be okay.

For the two other Geologists on here: I picked up on the P wave like a second before I was able to fully wake up. That surprised me, sensed the 'boom' before the shake. 2m displacement along about a 2km strike on the normal fault, AFAIK. The faults in that area have about a 60 degree dip, NW/SE strike. 40 km deep, and 13 km north of us. The Castle Mt Fault line is not really super active. There's an incredible amount of QTs above the bedrock providing some dampening, so lots of liquefaction around. Cool to feel the violent vertical motion vs the slow roll of others I've felt. I can only imagine what it felt like on the substrate rock nearby.

Time to hit the gym more, I felt my my belly fat interact with my back fat in a way that was unnerving.

7 more aftershocks since I started this post.

What was your favorite earthquake?
 
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Eric Stoltz said:
We're at 240+ aftershocks from the 7.2 here in PANC. Got my butt awoken by my roomie hollerin, the wife leaping outta bed, and everything on a shelf flying off at us. Was fun trying to stand for the 25 seconds of +/- .5g's, and +/- 45cm of vertical travel as the earth wiggled. We did throw on warm clothes and escaped right as the first big aftershock shook. We're okay, and the mess is all cleaned up.

Not one to get all fired up during exciting times, but these aftershocks keep my adrenaline pumping and we're getting exhausted. The first big one is the most impressive.

But, because this is a pilot board, my flight was canceled because half the pilots can't drive to the airport since the roads are kinda jacked up. And, there are some spectacular pics being made by pilots in super-duper-cubs and choppahs. Plus, the tower guys had to escape for a bit. The FAA made a ground stop to PANC for a bit to check the infrastructure of the airport. Jet fuel tanks and pipes are good. It's all good.

Any AK POA's need me to check on their airplane at PALH? I'll pet it and provide some comfort and let it know that everything will be okay.

For the two other Geologists on here: I picked up on the P wave like a second before I was able to fully wake up. That surprised me, sensed the 'boom' before the shake. 2m displacement along about a 2km strike on the normal fault, AFAIK. The faults in that area have about a 60 degree dip, NW/SE strike. 40 km deep, and 12 km north of us. Lots of liquefaction, too. Cool to feel the violent vertical motion vs the slow roll of others I've felt.

Time to hit the gym more, I felt my my belly fat interact with my back fat in a way that was unnerving.

7 more aftershocks since I started this post.

What was your favorite earthquake?
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Glad to year you're OK; we are too.
I put my "today's quake story" in this other thread:
https://www.pilotsofamerica.com/community/threads/shout-out-to.115352/
...includes important details such as how my liquor-cabinet inventory has been altered. :)

I can extend a similar offer to anyone with a plane at PAMR.

Biggest quake I've ever experienced, and I'm from California (but missed Loma Prieta because I was on a bus).
 
I was in a couple.... Northridge being the biggest one. It’s all fun and games till the damage started being tallied up.
 
Eric, I did not see any real geologist talk in your post. I recognize "P wave" and liquefaction from college science. Let me know when you are going to get real sciency and I will probably fall asleep. LOL

Glad to hear you are alright. You should go fly those planes besides pat them and tell them they will be ok. :)
 
That’s kinda cool Eric. Certainly don’t wish harm or damage to anyone. But super interesting from a science standpoint. I’ve only ever felt one earthquake and that was about 15 years ago in Indiana.

Hope all of you in AK are well.
 
Eric Stoltz said:
What was your favorite earthquake?
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I've been in a few quakes that occurred in/near Afghanistan, including the big one that hit Pakistan (2007??). That one felt like the whole building was being moved back and forth a few feet and lasted for what seemed like a couple minutes. We knew it was a bad one.
 
Eric Stoltz said:
We're at 240+ aftershocks from the 7.2 here in PANC...

...7 more aftershocks since I started this post.

What was your favorite earthquake?
Click to expand...

Glad to hear you and everyone else in the house are okay.

Favourite earthquake? Yellowstone 1959. I was a kid on a camping vacation. Not old enough to really understand the magnitude of what had happened, so it was an adventure bonus for me.
 
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Glad to hear you made it through okay. I think there might be 3 or 4 of use geologist on here.

My “favorite” earthquake was the 5.8 that hit central Va, mostly because I was 500 miles away and still had a long roll, sent the fish tank in the office I was in with a nice seiche.

Also, talk about having your priorities in order
“I grabbed the essentials,” Scaggs said. “Birth certificate, passport and Pappy Van Winkle,” she said, cradling the bottle in the crook of her elbow.”
https://www.washingtonpost.com/scie...ude-earthquake-alaska/?utm_term=.58a118ee402e
 
Eric Stoltz said:
What was your favorite earthquake?
Click to expand...
We'll never forget the Northridge Quake, January 17, 1994, at 4:31 AM. I awakened to the sound of my wife yelling, "Break his door down, if you have to!" (addressed to our son down the hall, referencing his younger brother in the next room). I also had a sensation of violent motion, akin to a pair of sneakers in a tumble dryer. About that time there was the sound of the grandfather clock falling against our bedroom door, and other background sounds of things breaking.

We gathered ourselves together and exited the house through the bedroom glass slider to the patio. It was a brilliantly-clear pre-dawn; warm for mid-January, with a mild "Santa Ana" wind -- the warm, dry wind that flows from the desert through passes and canyons into the Los Angeles coastal area in winter months -- in progress (some Californians -- myself included -- call it "earthquake weather"). But the patio was wet -- from water that had sloshed out of the swimming pool. And the ground was still shaking.

It was the most spectacular starry night sky we'd ever seen in Los Angeles, because city lights had been knocked out in the quake. We could see a small brush fire on the brushy hill north of us (likely a downed power line), and a glow in the northeast, from the gas main explosion on Balboa Boulevard in Granada Hills that took out an entire block of homes. It was bizarre. It seemed like Armageddon.

We greeted the sunrise with neighbors on our front lawns and in the street, making sure everyone was okay and waiting for enough daylight to go back into our homes to see what was left. A minor, and in hindsight amusing, annoyance was the fact that only a couple of hours before the quake, some of our son's teen pals had dropped by to toilet-paper the front of our house.

We were relatively fortunate. Structural damage was limited to the brick chimney and slumpstone property-line walls, all of which had to be replaced. Lots of knick-knacks in the house were broken. Because of the lateral motion of the quake, things that were on east or west walls fell, and things on north-south walls generally stayed put.

When the power came back on a couple of days later, and M5.0+ aftershocks were still happening regularly, a seismologist was on TV grinning like a kid with a new toy. "Boy, we sure learned a lot from this one," she gushed. "We didn't even know that fault was there. For all we know, this might just be a foreshock of an even bigger one!!" Thank you for sharing, doc.

And it wasn't just the initial quake ... the thousands of aftershocks that went on for months was what drove you nuts. And each time the shaking started, we remembered what the TV seismologist had said ...

Our swimming pool was our personal seismometer. If an aftershock was M5.0 or better, water sloshed over the edge onto the deck.

Our law firm, headquartered in Granada Hills, had a branch office in Palmdale. With the freeways down, what was normally a 45-minute drive between offices now took four hours. I used a rented Saratoga to haul files and office equipment from VNY to WJF (15 minutes each way), where our Palmdale attorney met me. My son rode with me on one trip so he could spend a few days with relatives there, away from the stress of the constant aftershocks.

Photos here: https://photos.app.goo.gl/SdFuYHNHSqVYQqjA8

Our hearts go out to the folks in Anchorage. We have an idea what you're going through. And I remember seeing news reports when I was a teenager, about the huge quake in Anchorage in 1964, I believe.
 
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Not really a single bad one, but I spent a summer in Denali National Park, flying tours around Mt. McKinley out of Kantishna Airport. It was weird, most were just minor earthquakes, but a person would hear it before feeling the shake. The first time I heard one I asked, "What was that..." And the shaking started about 5 seconds later.

After a couple weeks I was used to it. Until one rolled me out of my cot one evening. I was staying in a small log cabin that had been built on pilings on a slope of about 40 degrees. I was just waiting for everything to roll down the hill like Lincoln Logs...

Glad to hear you guys in ANC are Ok.
 
Fred Thomas said:
gniess seiche.
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FTFY

"Saaaayyyy-ssshhhhuh!" Said the prof to us undergrads. I haven't used that word for a long time!


Ice on Lake Hood made some undulating noises after one of the strong aftershocks. It too me a while to process that one.

Amazing how long the lines are at liquor stores. SM is outing the irritable, restless and discontent of Anchorage by posting pictures of the lines wrapping around the parking lots.

Sent from my SAMSUNG-SM-G891A using Tapatalk
 
Eric Stoltz said:
Amazing how long the lines are at liquor stores. SM is outing the irritable, restless and discontent of Anchorage by posting pictures of the lines wrapping around the parking lots.
Click to expand...

I could see that out in Kotz or Barrow because after work there is nothing else to do. A couple days of R&R in ANC usually left me pretty worn out. I had to go back to work to rest...
 
Eric Stoltz said:
What was your favorite earthquake?
Click to expand...

Loma Prieta in 1989. The epicenter was about 6 miles from our house in south San Jose. Our son was home playing video games with a friend (just shy of his 13th birthday). Grabbed his friend and pulled him into a doorway. When the shaking stopped he went out, turned off the electricity and gas to the house (no problems, but why take a chance?) and hopped on his bicycle to look for his sister. Not bad for a kid his age. There was nothing left standing inside the house. Shelves were emptied. it was a mess, but no structural damage.

I was at work, going through the review of another engineer in the group with my boss. By the time we realized this was a serious earthquake we couldn't get out of our chairs. All we could to was hang on and ride as his office came apart all around us. Once the shaking stopped I got up and ran down a couple doors to my office. A whole different story there. A drawer was open on one filing cabinet and a mug had walked off the edge and dropped into a box of drawings. Difference? His office was between columns holding up the building and mine had a column going through it. I grabbed an HT and joined the net on the club amateur radio repeater. Within 5 minutes we had a better picture of the situation in the company campus than security did. Didn't hurt that the president of the company joined our net, he was a ham, too.

When I finally got out of the office and headed home I was amazed at how people handled intersections with the power out. 4 way stop, just like they were supposed to. Took a while longer to get home, but no problems.

The building I was in had just had a seismic upgrade. Otherwise it would have pancaked and I wouldn't be here to tell about it. The architect who designed the upgrade, however, was one of the people killed in the Cyprus Street freeway collapse in Oakland. The wife of a 2nd cousin was one of the people pulled alive from that collapse. We had just finished a 10 meter RF semi-anechoic chamber the week before. It was built to seismic zone 4 standards, but we didn't plan on testing it. A single absorber cone (about 200 pounds) on the ceiling had come unclipped on one side and was hanging at an angle. A bridge was run from the building to the roof of the chamber to allow access to the roof for changing lightbulbs. I had specified that it was not to be connected to the chamber in case of unequal thermal expansion. The contractor had built a support structure that tied the building to the chamber and I had them remove that. What they couldn't remove was the weld connecting the deck of the bridge to the chamber. No problem, the earthquake sheared that right off.

Every commercial radio and TV station in the Bay Area was off the air for varying periods of time. A friend was one of the co-owners of Ch 36 in San Jose. It took them about 30 seconds to get their generator lit off, on-line and the transmitter back in service. He was proud of the fact that they were the first back on. Ch 11, the ABC outlet in San Jose, didn't return to the air until commercial power was restored at their transmitter site. Their transmitter was on Mt. Loma Prieta. They had a generator, but the earthquake shook their fuel tank loose and it rolled down the hill. No fuel equals no generator. KGO radio, 810 kHz, ran a 3 tower broadside array off the end of one of the bridges across the bay (near the south end). One tower was down, the second lost about a third of its length and the third was standing at an angle. Instead of their usual 50 kW into a directional antenna they were running 10 kW omni-directionally for a while until their antenna array could be rebuilt. The only radio service that seemed unaffected was amateur radio. I'm not aware of a single repeater that went off the air. We ran nets for quite some time providing emergency communications on a number of them.

The aftershocks had one benefit. They allowed me to calibrate what it takes to wake me up. Anything less than a 5.0 and I would sleep right through it. We also know what an earthquake sounds like before the building starts to shake. When we had the 7.0 earthquake in the Olympia area a number of years ago my wife heard it coming and had the kids in her classroom under their desks before the building started to shake. Nobody hurt in that one at her school, either.

You tend to remember the big ones when you live through them. Once was enough, thank you.
 
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Eric, how deep was that event in Anchorage? I remember we were told that the Northridge Quake was quite shallow, and the fault at a relatively flat angle, and that those contributed to the strong surface motion over a wide area.
 
It was about 25 miles deep, and 8 miles laterally from downtown.

Downtown is curiously empty tonight, but there is one restaurant open ("Crush"), which is full of revelers and people sharing stories and photos.
Ran into some university colleagues there, including some who are still without power or heat.
Hotels in town are adopting low rates and generous pet policies...
 
flhrci said:
Eric, I did not see any real geologist talk in your post. I recognize "P wave" and liquefaction from college science. Let me know when you are going to get real sciency and I will probably fall asleep. LOL

Glad to hear you are alright. You should go fly those planes besides pat them and tell them they will be ok. :)
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Haha!! Okay, I'll try to be boring. With the amount of energy the epicenter with the 1.84m slip, (310 degree rake) and a decent short trup of 1.4s, it kinda surprised me that the sub fault moment of 2.5^18Nm made for a great amount of aftershocks along the W-E strike - nearly linearly. And a tremendous amount of T energy along the bisect in a logMo manner, causing the violent 5m rise and low .6m slip. (Mo of this 'tremor' pens to something like 794,328,234,724,282 J) Someone can certainly check my work, of course.
 
1979 Imperial Valley CA earthquake. Laying under a bush in hiding near Warner Springs, CA in Navy SERE school and the ground kinda jumped and fell out from under me ... Dang - Navy really ramped up the excitement for this training!

edit - or it may have been 1978 - Santa Barbara quake ... I can't remember now!
 
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Eric Stoltz said:
Haha!! Okay, I'll try to be boring. With the amount of energy the epicenter with the 1.84m slip, (310 degree rake) and a decent short trup of 1.4s, it kinda surprised me that the sub fault moment of 2.5^18Nm made for a great amount of aftershocks along the W-E strike - nearly linearly. And a tremendous amount of T energy along the bisect in a logMo manner, causing the violent 5m rise and low .6m slip. (Mo of this 'tremor' pens to something like 794,328,234,724,282 J) Someone can certainly check my work, of course.
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Much better! I have no idea what you said there and I feel myself nodding off. :)
 
I've been in two mild earthquakes. One in New Zealand, where "The big one" is always a possibility. The scary thing there was we were on a middle floor (say the 5th floor) of a hotel and that's not a great place to be if the earthquake is a big one. It turned out to be a sub-5, so wasn't a big deal.

The other one was here in NW Georgia. I woke up to jangling drawer pulls and a growling border collie (who also said "woof" at the earthquake) and knew immediately what it was. When it ended (it was right at a 5), I went back to sleep.
 
The biggest one I experienced was in 2010 when I was living in Torrance CA and a 7.2 hit Baja Mexico. It still had some punch when it hit us and sort of felt like a wave. After it went through, we looked out of our apartment at the swimming pool which had good sized waves going back and forth in it. There were also a couple of very minor ones while I lived in California.

Others were a small one in Indiana in 2004 and another small one in Memphis in 2012. There have been some small ones reported in NC since I lived here but I didn’t feel them.

Luckily I never suffered any damage or injury as a result of one.

Wishing everyone in Alaska well.
 
The scariest one I was in was when I was living in a high rise apartment in Athens, Greece as a kid. I thought the building was going to come down. I slept through an earthquake in San Diego, and felt some of the shocks from Loma Prieta.

Incidentally, my folks were stuck on the Bay Bridge for 14 hours after Loma Prieta hit. They were maybe a dozen car lengths from the collapsed span. I know people that lost people from that quake.
 
Now that things are hopefully settling down, I'm curious how downtown fared. I have a cousin that owns a store on 4th Avenue.
 
kyleb said:
I've been in two mild earthquakes. One in New Zealand, where "The big one" is always a possibility. The scary thing there was we were on a middle floor (say the 5th floor) of a hotel and that's not a great place to be if the earthquake is a big one. It turned out to be a sub-5, so wasn't a big deal.

The other one was here in NW Georgia. I woke up to jangling drawer pulls and a growling border collie (who also said "woof" at the earthquake) and knew immediately what it was. When it ended (it was right at a 5), I went back to sleep.
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Likewise I've only felt two. One in late 60s when I was a kid, I was sitting in a chair and just felt it move a bit and was puzzled why. Later that day I heard there had been a mild earthquake. Most recent was just 3 or so years ago in the mountains of NC, I was driving down a mountain and felt the road move if that makes sense. A bout of brief vertigo you could call it. When I got to my destination sure enough there was news of a quake at exactly the time I felt it, I think it was centered in eastern TN.

Worse for me was hurricanes and a tornado near miss. But by far the most memorable phenomenon I've experienced was ball lightning in the den that hung around for a second then "exploded". I was alone except for two dogs so have no one to corroborate. :(
 
A few days after the Northridge quake I made one of my Palmdale shuttle trips in the Saratoga. Just as I started to taxi out at VNY a sharp little M4.5 aftershock hit. It felt almost like a flat tire, but I knew what it was.

I keyed the mic and told Ground Control I wanted to file a PIREP for moderate turbulence on the east taxiway.
 
I've never experienced a real earthquake, but there was a quarry about a half mile from my parents' house that would occasionally blast on our side, and it'd shake the house. Everything would rumble and there would be waves in my waterbed. My mom complained, and they sent someone out with what I assume was a seismograph to measure it for one blast, but I think they must have blasted on the other side or something, because that time we didn't feel a thing. I've always wondered what those would have actually measured on the Richter...

I've seen several tornados, though...
 
Anymouse said:
Now that things are hopefully settling down, I'm curious how downtown fared. I have a cousin that owns a store on 4th Avenue.
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Downtown is fine. Really limited building damage, gratefully. Just had a 4.8 a minute or few ago.

Here's the link we keep checking to watch and guess how much "that one" was. Each dot is a quake that happened within the last 24 hrs. The size of the circle is the intensity, color too. We feel the ones that are 2.5 and greater. So, yay. Fun time trying to stay asleep.
 
Thanks!!

Saw a meme on Facebook that showed Bill the Cat. The caption said "Anchorage residents after two days of aftershocks." Or something to that effect.
 
I’ve only experienced one for sure, and maybe a second one here in the SC coastal plain. The one I definitely recall was around 3.0 and occurred during breakfast. Just rumbling and rattling for about 30 seconds or so.
 
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