A very tragic scene is playing out in Washington state. Sadly, this even was entirely avoidable. However, as is so often the case, real estate values trump geology.

The NY Times article In Ocean of Mud, a Plea: Leave Me and Find My Wife has a good sidebar explaining in simple terms how landslides happen. Local officials have claimed that this disaster could not have been forseen, but that is B*** Sh**, to put it mildly. Down about the middle of the linked NYT article is an pre slide air photo ("Extent of the Mudslide"). Anyone with the least bit of geologic background would recognize the old scarp from a previous slide, and the active undercutting of the toe of the old slide by the river.

And in fact, the Seattle Times article Risk of slide ‘unforeseen’? Warnings go back decades points out that this slide had been recognized and well documented numerous times in the past. Unfortunately, as the geologist interviewed in the video points out, people are unwilling to listen to mere scientists. And, in many cases, real estate interests have blocked efforts at zoning around recognized hazards. In some cases, geologists, engineeers, and others have been threatened with law suites if by publisizing hazards they impact real estate values.

The Atlantic photo spread At Least 14 Dead in Washington State Mudslide shows a number of good views of the slide and the body recovery efforts. In particular check out photo #10 which shows a before and after view. As in the photo noted in the NYT article, it is trivial for the trained eye to recognize the old slide being undercut by the river.

Most unfortunate.

I got on a soap box and ranted for a few paragraphs. But no one wants to hear it, so I just deleted it and will let it be.

Most unfortunate.

Nothing is more inevitable than gravity. My condolences to everyone impacted by this disaster.

It is sad that people have died and homes have been destroyed in Washington.

It is also sad that people/governments decide to build homes in cities on the coast that are below sea level, along known and active earthquake fault lines, below active volcanoes, deep in tinder-dry forests, below a mud-slide hill that has already given way multiple times before, etc. You can't avoid all hazards, but you think you'd be able to avoid the obviously predictable ones.

Not many places left to live, then.

Blizzards, Heat Waves, Drought, Tornadoes, Forest and Range fires. Floods, Volcanoes, Avalanche, Earth Quake, Allergies, Tick fevers.Cholera, Valley Fever, Malaria, West Nile, Wildlife attacks, War, Riots, Distant Medical Facilities, Nuclear Disasters, Oil Spills, Blackouts and Brownouts, Drug Cartels and Gangs.

There seems to be something for everyone.

This event evokes memories of the 2005-06 La Conchita landslide, right next door to me, also with multiple fatalities. Digging a bit into history, it seems that in 1906,the Southern Pacific dug away an area to serve as a catchment basin for the persistent landslides that had been plaguing their right of way along the coast. In 1926, the first houses were built within the catchment area.

If you drive North on US101, look to your right as you pass La Conchita. Note the funny dirt piles.. They are the landslide. Take note of the steep cliffs all around - landslides of the future.

You can build to resist and survive the effects of earthquakes, tornadoes, and hurricanes, but things like massive landslide and tsunamis are a different ballgame.

How can you get a mortgage or homeowner's insurance in such a situation? Regardless of zoning or individual stubbornness, you'd think private lenders and insurers would try avoid massive loss situations.

Natural hazards like we were talking about in the origin post in this thread just don't move into an area unexpectedly. They are known about well in advance. Thus highly predictable. But human-made hazards (riots, gangs, etc.) can "move in" and turn a previously safe place into a dangerous one. This does not happen overnight though, you will see the area declining over time, and thus you could call these hazards "somewhat predictable".

True enough -nearly every place is subject to various hazards and vicissitudes. Know Your Local Hazard Profile!

Some are almost universal - wildfires come to mind. Others are more regional in scope - in SoCal, we are concerned with earthquakes, but not with hurricanes. In Florida, the opposite is true.

Every place has it's STOBOR.

STOBOR? Acronym or Heinlein?

Clear cutting appears to be part of the problem in this landslide. In fact clear cutting beyond the permit boundaries by a European owned company.

One can't always escape or mitigate other peoples actions.

It's partly because they aren't looking at an aerial view with an engineer or geologist's knowledge. Looking at the before picture, it's obvious that this is the next bite out of the cliff face. It will continue to do this until it reaches a profile where the strength of the soil can support the cliff. This one was bigger due to a "perfect storm" of conditions.

I see they just found the body of that missing four month old child. Heart breaking.

An acquaintance of mine in the local Red Cross introduced me to a saying years ago I would guess many here have heard ... "All disasters are local", so +1 on "Know Your Local Hazard Profile!"

Short of a major comet/asteroid impact level event or a supervolcano, generally true.


The above comment is not meant to imply that because an event is not local to me I'm removed from it.

I do feel bad for all those who are suffering directly from this and hope they can find some peace, eventually.

The TV news was just mentioning that the mud was 70 feet thick in some places. And it is contaminated with sewage and various chemicals. Makes for a tough recovery operation.

Yeah, an epic wall of mud. I read a report that said the volume of the slide contained three times the material of Hoover Dam, just to give an idea of the monumental scale of the disaster.

Three times Hoover Dam? That's a big dam, so that's a mind boggling amount of mud to search through. I presume that it would be very, very difficult to recover all the bodies in such a massive amount of material. A 9/11 Ground Zero-type response could do it, but I don't think those kinds of resources are available here.

I wonder--somewhere down the line, does a developer eventually grade the area and then build more housing on top of it??? It wouldn't surprise me, unfortunately.

More likely the county buys the land, they complete the search, do some regrading for safety and it becomes a county memorial park.

For that use, they may not need to do a whole lot of grading. I'd start by getting a specialist to look at the cliff face where the slide started. This slide may have changed the profile enough to stabilize the slope.

For anything else, I'd want a geotech looking at the foundations of anything bigger than an old style outhouse.