Evacuations in Yakima County due to cracks at Rattlesnake Ridge

[Billie D]

Not looking good

https://www.kxly.com/news/rattlesnake-ridge-fissure-prompts-evacuation-notice/680586243

Hoping this does not become another 2014 Oso. 

[Mr. Bill]

From the Yakima Herald:

Majority hold off on call to evacuate near Rattlesnake Ridge

Watching, waiting for Rattlesnake Ridge slide

[Docwatmo]

About 8 or 10 miles east of that an old airstrip/training area.  When I was in the Army, we did an exercise at that training center and got to land C-130 on the strip and setup our comms van and gear. In one of the hangers were 3 of the planes from the movie "Always".  This was back in 92 or 93, so I don't know if they are still there or not.   But it is one of my fondest memories from the Army during my Stint at Ft Lewis. 

[LVWood]

There is a video of the crack taken from a drone or something. It would seem the crack is probably the responsibility of the aggregate pit adjacent to it.
Over excavation or blasting.

[CarbideAndIron]

"Many residents, of modest means, are reluctant to leave — likely out of concern of finding replacement housing."

I'd say 99% of people would be worried about finding replacement housing in this housing market, not just ones of "modest means".
Scary looking crack, that is a lot of terra firma that could be looking for a new home. And with as bare as it is, there's pretty much zero vegetation holding the ground together.

[Billie D]

It looks like it is going to go - one way or another.
Hoping for a nice slow crawl while it's still dry, vs. once the rain comes and it takes out even more.
Although, either way it looks like it will be horrible.  Especially if people aren't leaving that will be right in the path.

[Cedar]

Gravity always wins. Look up the "Hope Slide" in British Columbia. I went to see it in 2007, pretty impressive. Two people are buried forever under it. A man named Norman convinced a greyhound bus to turn around and saved many lives.

The "Rattlesnake Ridge" looks alot like the "Hope Slide" to me.

Cedar

[Mr. Bill]

As best as I can tell from news images and Google satellite imagery, there are no houses directly below (west of) the crack.  The nearest are in a cluster of trailers and old houses just south of the quarry.  So the danger depends on which way the collapse occurs -- if it goes west, it blocks Thorp Rd, and maybe the freeway, and just possibly the Yakima River.  If it goes south in a catastrophic manner through the quarry, it could reach the homes, although it looks like the shape of the quarry might trap the slide and protect the homes.

https://www.google.com/maps/@46.5262163,-120.4654268,1545m/data=!3m1!1e3

Also, when the article says "of modest means", they mean folks living in very-low-income rural housing.  Check Google Street View to see.

[rustyknife]

Not to far from where I live on the way to Richland, Ore is a slide called the "Devils Slide". There is a spot that you can pull off the road and view the whole slide. No pictures or film can possibly show with such clarity the massive amount of material and destruction something like this can expend. 

[Mr. Bill]

Some detailed into from the WA Dept. of Natural Resources:

https://www.dnr.wa.gov/rattlesnake-hills-landslide

Event Summary
Approximately 20 acres in the Rattlesnake Hills near Union Gap, WA is currently moving at a rate of ~1.5 ft/week in a southward direction. The movement is ongoing and a failure event is projected to occur in late-January or February 2018, based on current estimates from geologists and engineers monitoring the landslide. The type of movement expected is a translational landslide composed of blocks of basalt sliding on a weaker sedimentary layer. The geologists and engineers monitoring the landslide suggest that the most probable scenario is that the landslide will move south and accumulate into the quarry. In this scenario, rockfall is expected to the west and south that may impact Thorp Rd., which has been closed since late December by Yakima County as a precaution. There are other low-probability scenarios where the landslide could reach I-82 and impact homes south of the quarry, or potentially reach the Yakima River. These scenarios are less likely. Precautions and plans are in place to take action if monitoring data suggests that this may happen. ...

More info from the WA Dept. of Transportation:

https://wsdotblog.blogspot.com/2018/01/crews-monitoring-land-movement-on.html

[Alan Georges]

I can get my head around all kinds of natural disaster – walls of water, 130+ mph winds, disappearing islands, etc. – but an expanding chasm and massively sliding earth just creeps me way the hell out.

[Billie D]

It really is scary.  We have friends that drive that road daily, the thought of what could / could have happened is terrifying.
I guess, at least they are monitoring it.  But, it is going to go when it is ready.  We can guess, but that really is all that it is.

[Mintbird]

I found this interesting video dated Jan. 14. It looks like a drone flyover of the area.

https://m.youtube.com/watch?v=-NB4IUB4evE

[Billie D]

Saw something on the news this weekend about people sneaking in and hiking around the crack.... smh... 

[archer]

Saw something on the news this weekend about people sneaking in and hiking around the crack.... smh... 

trying to get a darwin award..

[Mr. Bill]

Two articles from the Yakima Herald:

Rattlesnake Ridge landslide millions of years in the making

...The lava that came pouring out starting some 17 million years ago is 2 miles thick in places. The eruptions took place over a roughly 5 million-year period. Thousands and thousands of years passed between eruptions. The layers would cool. Life would resume. Plants and animals would thrive. Then another layer of lava would come rolling across the landscape. Trapped between lava flows would be interbeds of soil, rocks and occasionally an animal unlucky enough to have been overtaken by an eruption of lava — the mold of a rhinoceros can be found in the basalt near Lower Grand Coulee.

Rattlesnake Ridge is composed of roughly five layers of solidified lava known as basalt. ...

The Pomona [layer] — the formation that’s sliding — is about 150 feet thick. Below it is an earlier lava flow known as the Umatilla formation. Between the two is an interbed that’s allowing the Pomona to slide. ...

Understanding Central Washington’s geology is key to knowing how the deadly 2014 Oso slide northwest of Everett was a very different situation...

Rattlesnake Ridge’s basalt is dark, fine-grained and incredibly dense. Sedimentary rocks — which formed the majority of the Oso slide — are created when sand, mud and pebbles cement together in water. They are soft and comparatively brittle, which meant when the Oso slide began, the land broke apart more easily and moved far faster than a basalt slide would. ...

Rattlesnake Ridge-area residents who evacuated now face having to pay back rent

Residents evacuated from the base of Rattlesnake Ridge amid concerns of a potential massive slide are worried they will have to pay rent for the time they were absent in order to be allowed to return to their homes.

That concern was voiced during a Friday morning meeting with Yakima Valley Office of Emergency Management officials, who issued evacuation notices early last month. Officials called the meeting to let residents know why the evacuation notice was lifted — a recent geological report found no immediate danger of a massive slide anytime soon. ...

About 20 people, many of them families, have been staying at the Ledgestone Hotel on Fair Avenue since the evacuation. Columbia Asphalt and Gravel, which operates a quarry on the ridge, has agreed to cover their hotel costs until Feb. 12. ...

Landlord Patty Dills said she does expect tenants to pay January and February rent in order to return. Dills said residents left without notifying her son Nathan Dills, who manages the property. ...

Company spokesman K.C. Klosterman said Columbia Asphalt attempted to work with the landlord to cover one month’s rent but was unable to reach an agreement. ...

[Billie D]

Funny you don't hear much about it on the news anymore.  Last I heard they are now thinking years??
My booty would be out of there.

[Mr. Bill]

Update: the landslide is still moving southward, but the speed has decelerated from its high of 1.7 ft/wk down to 0.7 ft/wk as of January 2019.  Southward is the "safe" direction because it means most of the slide will end up in the quarry.  Graph from https://www.dnr.wa.gov/rattlesnake-hills-landslide :