Tuesday, December 4, 2018

Magnitude 7.0 Earthquake Hits Hard

THE QUAKE.

edit: USGS would later increase the magnitude to a 7.1

8:29 AM on Friday. When the quake struck: I was on the Glenn Highway approaching the exit for Mirror Lake, driving in later than normal because I was going direct to the training facility to be a mentor for the graduation table top exercise for DoD's Defense Support of Civil Authorities course on the Army side of JBER (the course that teaches DoD members how to help civil authorities recover from a natural disaster - ironically). Jolene was just about to end her first period Chemistry class upstairs at Career Tech High School. Landon was in a Computer Programming course, also upstairs in the same building, about 30 yards away from Jolene's classroom. Grayson was walking a pencil he had borrowed up to the front of the room to his science teacher in Teeland Middle School, in sight of Career Tech High School, just a couple hundred yards away. The kids and teachers got under their desks, held on, and rode it out. Power went out as they were hanging on during severe shaking and falling tiles in the dark.


The quake was a rupture within the Pacific plate,  which is being pushed under the North American plate, and was centered across Cook Inlet from Anchorage. Shown above is the originally issued shaking intensity map. Luckily, Jolene and the boys' buildings were close to the "VI" intensity range, and there was minimal damage to their buildings. The Glenn Highway runs along the east side of the "VIII" range pictured above, and our house, in Knik-Fairview, sits right in the most severe range of shaking from this particular quake. The magnitude (7.0) describes the total energy released from the fault slip, but the real useful info comes from this shaking intensity map, showing where that energy is directed. In this case, the most intense shaking was focused in three areas - 1) south in the waters Cook Inlet; 2) north in the Big Lake area (hit hard); and 3) NE of the epicenter covering Knik Arm of Cook Inlet, but extending over the land area north of Knik Arm, in Knik-Fairview (also hit hard) - where our house sits. Eagle River also sustained quite a bit of damage, even though this map doesn't show it in the highest shaking zone.


Another view of the depth of the rupture from the Alaska Earthquake Center.

The severe portion of the shaking lasted about 30 seconds. The above video is of our living room during only the last ~5 seconds of shaking (camera was late coming on), and this was our least damaged room (have the volume up when you listen, to get the full effect).

This camera was sitting on a dresser in our downstairs guest room, pointing towards our back door. It came on earlier than the one in the living room, and caught most of the 30 seconds of severe shaking.

Jolene had to shelter in place with the students until they had all been picked up. Landon left to go get Grayson from Teeland and bring him back to CTHS with Jolene. When he arrived to Jolene's classroom, hours after the quake, Grayson was still grasping that pencil he was holding when the quake struck :)

Jolene made it home about 2:30 pm (some of the roads were damaged, and traffic lights out), six hours after the quake. I couldn't leave work, as we were coordinating DoD's response, and so we talked via text about how to turn off the gas in case of a leak, and the well pump in case of water leak. Fortunately,  when she arrived, there were no gas leaks, and only the garage was flooded from the leaking hot water heater (though some of the water was leaking into adjacent walls as well). She got the water off with help from a neighbor, and as she walked in, she had to process the massive mess that remained. Our piano, on wheels, had hit the wall and turned on the living room light switch (that's why the light is on in the video) then it rolled over to the other end of the wall and turned on the gas switch to our fireplace, before it rolled out to where you see it in the video. So when Jolene came in and looked across the floors full of glass and debris, she saw the fireplace was lit. Luckily there was no gas leak.


Our laundry room.


Kitchen.


Kitchen.


Pantry door wouldn't open, so I had to remove it from the hinges.


Jolene, choosing her steps wisely while she tackles the floors full of glass.


Drawers were thrown open, and glasses falling from above crashed into them, filling the drawers with glass and breaking items in the drawers.


Living room. In the video, you can see this TV hung on til the last few seconds of severe shaking, then it took a leap.


Our traveling piano, pieces of the fireplace, and various broken items.


Even the short nightstands were toppled.


Shower door in master bath.


The hot water heater ripped out the lower earthquake strap from the stud it was anchored in, and punched through the dry wall next to it, pulling the supply pipes out of the wall and splitting them at the joints above the unit.....flooding water into the garage.




Landscaping damage.


For the next few days, we had numerous aftershocks. Just had another as I write this, on day 5. Highest was a 5.7 aftershock.


Outside, our bluff suffered some damage. Here's a crack 6 feet back from the bluff edge (about 30 feet from our foundation).


About 8 inches at the widest point, and appears to be only 1 foot deep.


Below the bluff, the organic layer in the top foot slid down the bluff. At first look, it appears that the bluff core (the massive hill of rocks under the top organic layer, which was deposited here thousands of years ago by a retreating glacier) didn't move much, if any. It's in those rocks that our house foundation is anchored, and it appears the slide on the bluff slope was in the top 1 foot of organic matter. The bluff appears to be stable (at least as far as we can see), but a geo-technical engineering assessment will be made before Spring breakup.


More cracks along the bluff top.


For my experience - in the picture above, I was driving south on the Glenn (top to bottom in the picture), and as I changed lanes left to right, I thought I blew a tire, then saw all the lights on poles flicker and sway back and forth, followed by explosions ahead on the horizon (turned out to be electrical transformers in Anchorage). Once I realized it was a big earthquake, I decided to exit at Mirror Lake since it was difficult to keep the car squarely on the road due to the shaking. I took this exit in the picture, and as I drove down the exit lane, I saw the road looking like it buckled behind me in the rear view mirror. The road was vertical for a split second in the rear view mirror, then disappeared behind me. I drove to the bottom of the exit ramp (it is an underpass), and collected my thoughts. No one was behind me on the Glenn initially (a rare empty road that time of day, thankfully), but before I could go back up the ramp to see if the road was damaged to warn oncoming traffic, another car appeared slowly and maneuvered past the area without problem. So I decided it must not be damaged very bad (couldn't see it from where I was below the road). Jolene texted that they were OK. I really wanted to turn around and go back to the Valley to get Jolene and the kids and check on the house - but cell phones were still up, Jolene and the boys were OK, and the cameras showed that at least the house didn't collapse. So I continued on towards Anchorage. All the radio stations were just static (felt eerie selecting preset 1-static, preset 2-static, preset 3-static...), and when they finally came back on, the airwaves were filled with just the emergency broadcast. Later, I saw the pictures of the crater that collapsed right behind me, and it was far worse than I thought at the time. I was the last vehicle to cross that pavement before it collapsed, and am thankful that no one was right behind me.


Another view of the cratered road at the Mirror Lake exit.


Farther North, just four miles from our house, Vine Road was damaged due to the severe shaking. This is four miles farther north from the epicenter than our house, which reemphasizes that shaking zone can mean more than distance from the epicenter as far as damage is concerned. Our house turned out to be ~10 miles from the epicenter, but in the most severe shaking zone, as was Vine Road.


Ground level view of Vine Road.


Anchorage was mostly in the lower shaking zones, but even so they suffered road damage. Here is Minnesota Drive near the airport.


Point Mackenzie road. One of my action officers was at Pt Mackenzie, near the epicenter, when it hit, and he drove his truck (carefully) down this road to get home.


Near Lazy Mountain, out in Palmer. Palmer saw a lower intensity, but still had damage.


Along the Seward Highway south of Anchorage.


A still shot of our trail cam. (Ignore the timestamp, I haven't set those clocks.) This was 10 minutes before the earthquake.


And this is a still from the very end of the quake. Notice the trees rooted just below the bluff have slid down 3-4 feet, both in height and distance from the camera.

THE RECOVERY

36 hours after the quake, we started to have time to check in on the news to see how everyone was doing. I spent that first day and night in Anchorage, helping with DoD's small part of the recovery effort, and came back home before sunrise the next day. Jolene had already done an AMAZING job of keeping the boys focused and cleaning up most of the massive amount of glass that covered most floors (with only a few cuts on her hands to show for it). Once I got home, we took the pantry door off the hinges since it was jammed closed, and got access to some strong smells that were emanating from all the broken bottles and jars piled up behind that door. Next we used a come-along and car jack to move the hot water heater back into place, shimmed the broken table it was sitting on, replaced the supply pipes with some help from a plumbing crew that was going house to house, and got the hot water flowing again after only a day without. By the end of the first 24 hours, we had heat, power, hot water, and cell service. Compare that with other ~7 magnitude earthquakes (Haiti's ~7.0 magnitude quake in 2010 tragically killed an estimated 200,000+ people, and a year afterwards most of the population still had no permanent power source). Bottom line is that we are very, very grateful, it could have been so much worse.




Re-building the landscaping retaining walls - day 3.




Our only remaining glassware in the house...just a few drinking glasses.


Jolene returns order to the pantry. I was eventually able to piece together enough other random door parts that I could engineer a fix, and re-hang the pantry door.


Laundry room, almost looking like its old self, plus some cracks in the walls and tile.


We had three flat screens in various rooms, and one old crt tv in storage in the garage. The three flat screens fell short distances onto carpet or wood floor, and all broke beyond repair, but that 22 yr old crt tv that we bought after we married, it fell 4 feet face first onto a concrete floor - and it still works. By the way, it is the only tv we owned that was Made in the USA!


No more glass shower doors for us!


Here's another view of the little mini-land-slide on the bluff.


Heidi-cat says these new ground features on the bluff make a great hiding place to hunt from.


The local grocery store, making the best from the mess.


Lots and lots of dry wall separations and holes.  Here the stand for my Japanese swords fell off the back of the entertainment center, and then when it slide back to the wall, it impaled that stand through the drywall.


Our biggest crack, by the front door. This is the crack that produced all the debris floating down in that first video.


Stairwell crack.


Downstairs family room.


Landon's room has this crack along a dry wall seam all the way around the room.


More cracks in Landon's room.


More of Landon's room.


Lots of trim was pushed free from the wall. The house did a tremendous amount of flexing back and forth during the quake, causing all these cracks and tears. To add to the the drywall cracks, there were numerous damaged areas to the wood floor, counter tops, tile separations from back splashes, window casing cracks, and siding separations. There will be lots of repair work to do.


DOT doing some good work with the repairs, in only a few days.


Well, I wish our house was that easy to get back together, but AK DOT really came through getting the road repairs done practically over the weekend.


Even the sink hole that opened up just behind me on the Glenn Highway that morning was fixed over the weekend.


Vine Road was the last to be repaired, but was completed in a couple of days once the work began.


Sun setting on day 4. Thankful that we all made it through uninjured, and that the damage wasn't worse. All told, this 7.0 magnitude quake did not result in any deaths anywhere in the state - which we consider a miracle! Jolene baked cookies last night as we finished some of the cleaning up and repairs for the day - she said it would help make it seem like things were back to normal (wise woman!).

(Note: some of the photos (of road damage, etc) are copied from news sites and posts from facebook, not all are our photos)

**Edit 1/13/19: Now that our structural engineering inspection has occurred, there was more substantial damage than we initially thought, much of it structural, unfortunately, and will involve some complicated repairs.




Our cracks in the foundation will need to be repaired.


We had an internal load-bearing wall shift on the foundation due to being inadequately secured by J-bolts/hold-downs as it should have been, and it will need to be moved back in place, which will involve lifting a portion of the floor joists it supports.


The below-grade portion of the wall in Landon's room is likely compromised due to inadequate bracing, causing the wall to bow and the window casing to begin to give way, and the concrete block portion of the wall will likely need to be rebuilt with a different design.


We have some additional damage in the attic to truss members, but doesn't appear to require immediate replacement. Cracks in the garage and downstairs den poured slabs will also need repaired.


One of our main support beams in the crawl space may need replacing. If it does, we may have to lift the entire house to do the repairs.




We lost one chandelier to electrical short days after the earthquake, due to the the bending of crossbars and twisting of wires as they spun, and upon inspection will be replacing all the light support crossbars.




There's also some work to do on the external siding which came loose in places, and we'll be rebuilding the small deck outside our bedroom, as well as the concrete pad it sits on.

All in all, repairing the house will be a major project over the next few years......and during that time, we'll be praying for no more earthquakes!