Notes on the Mesa County, Colorado Landslide

A very large landslide that translated into a very very big mud flow took place in western Colorado last Sunday. Based on news report images and a helicopter flyover footage, I figured out the location and did some old report reading and geology searching. The fly-over is below: 

I very roughly estimated the extent of the landslide on the following GoogleEarth image.

Perhaps the most remarkable thing about this slide is that a portion of the mud flow flowed up and over a ridge that was on the order of 200 feet above the base of the valley.

An oblique view of the headwall of the slide location shows that there was a classic down dropped block.

The image also shows some shallow surface failures or erosion on the block down slope side of the block. The landslide images appear to indicate that pre existing block moved again, perhaps dropping 200 to 300 feet and possibly expansion to the sides.

Baum and Odom (1996) provide a description of geology units and mechanisms of similar slides along the outer perimeter of Grand Mesa, the high (10,000-foot) plateau in western Colorado where the slide took place. A geology map (http://ngmdb.usgs.gov/Prodesc/proddesc_9117.htm) of the area to west of this site showing the perimeter of the Grand Mesa covered with large areas mapped as landslides. (If you look at the map, the Grand Mesa is on the southwest corner of the map.) In addition to the deep-seated failure mechanism in the underlying clay formations, this is an area that was glaciated - the Grand Mesa is over 10,000 feet.

Wayne Ranney has some great links on his blog of pictures and a further broader and interesting discussion of these types of landslides with links to the papers.

The slide appears to fit in well with the mechanisms discussed by Baum and Odom as a large intact rotational block of coherent bedrock over very soft Green River and Wasatch Formations of silts and clays. I have done some work in the Green River Formation clays and they are really a messy formation to try to walk around on when wet. There is a very strong translational component to these slides post block failure and seeing the extent of the mud flow perhaps a bit easier to understand why these slides are so extensive and rotated blocks end up so far from the rime area of the mesa.

While this area has been mapped as consisting of landslide deposits over broad areas, the Baum and Odom paper suggests much of the sliding is very old. This slide might be one of those low frequency but very large events that will provide the math inclined lots of opportunity to study run out distances.

I'm not sure we have anything quite like these types of landslides in Washington State. The closest might be the weak clay units in the Ringold Formation in south central Washington's Franklin County or failures within sub basalt units underlying the Columbia River Flood Basalt. Deep rotational slides that then turn into translational slides - future posts.

EarthFix: Whatcom County's Approach to a Landslide Risk

Ashley Ahearn with EarthFix/KUOW produced a story about Canyon Creek: earthfix.kuow.org/one-countys-controversial-move-to-protect-homeowners. I appreciated that John Thompson with Whatcom County was able to help with this story. Whatcom County should be proud of how the this hazard was addressed.

Ashley is one of several reporters I talked with after the Oso/Hazel Landslide event. Overall a good experience. The key decisions made at Canyon Creek in Whatcom County took place at roughly the same time that key decisions were made regarding buyouts of properties below the Hazel/Oso Landslide area. The Whatcom County Council that voted for the buyout was a very strong property rights/conservative council.

Ken Mann, a current County Council member, noted in the story that he likely would have voted against the buy out of properties and he makes an argument that is essentially the exact same argument the majority of the Council made at that the time the issue first came up. It took several votes and a lot of education before the Council opted for the buy out approach. The position Ken takes is a good argument; however, in this case as in other cases, property buyers and home owners had no way of knowing they were in a hazardous location at the time of purchase. At the time of approval of the subdivision and creation of the home lots, the county planners likely thought the area safe. The hazard became apparent after the fact. Furthermore, the original levee the county had built had actually increased the risk of a catastrophic event. Besides the risk to the home, the levee alignment was proving to pose a significant risk to the State Highway. (I always thought the State DOT should have helped fund the project as the cost post failure would have been very high). There were also significant salmon habitat issues with this project that allowed for a fair bit of the project being funded via state and federal grants.

Appropriate for the Day: An Eala Bhàn

2014 Geologic Pilgrimage: Macellum of Pozzuoli

Some time ago I was at a small dinner party and guests were asked to describe spiritual pilgrimages they had made. Each guest began to take turns describing a pilgrimage they had made and planned to make. Fortunately I had a bit of time to think of something and invented past and future pilgrimages on the spot - geologic pilgrimages. I have since had at least one geologic pilgrimage a year. I have posted a few recent ones:   

Copalis River

moment-in-deep-time-back-to-back

bonnie-lake-precambrian-schist

Lisa and I recently returned from a vacation where I tacked on a geologic pilgrimage to a place west of Napoli that I missed on a previous trip. Like any pilgrimage, half the fun is getting there.

Commuter rail station in centro Napoli

The columns are a short walk from the train station in Pozzuoli. 

  

Marcellum of Pozzuoli

The Macellum is a former market that was built on the site in approximately 200 AD. It was initially thought to be a temple and is thus still locally called Serapeum (temple of Serapis) despite the site long having been determined not to be a temple.

The geologic aspect is the dark band across the lower third of the columns. The band was formed by borings of marine molluscs Lithophaga.

Band of borings in columns 

The columns had been partially buried in marine sediment until they were excavated in 1750. The borings were identified fairly early as the work of Lithophaga. The fact that a building constructed in 200 AD had subsided below sea-level and stayed partially below sea-level long enough to be partially buried and used as a substrate by molluscs and then rose out of the sea provided a stimulating point of debate in the early days of geology. 

Charles Lyell discussed the columns at length (darwin-online.org.uk/content/pageseq=473) as evidence for subsidence and uplift in Principles of Geology (1830) and used a sketch of the columns as a front piece to the book and included a cross section of the column location.

Front piece to Principles of Geology 

Lyell's cross sections of Pozzuoli

Subsequent study and understanding of the area of Pozzuoli further explains the subsidence and uplift. Pozzuoli is located within a super volcano caldera on a scale not to dissimilar to the Yellowstone Caldera. Rather disconcerting that the floor of the caldera has been giving the columns and city a bit of a ride up and down as magma pushes upward under the area. The nearby more famous Vesuvius of Pompeii fame is hazardous enough, but is not the only volcanic threat in the area.

Vesuvius from Napoli

Change in Oregon

A RULING.pdf via a Federal District Court on Oregon Marriage has some personal notes in it. The judge is my younger brother. He reminds us how it once was:

"Generations of Americans, my own included, were raised in a world in which homosexuality was believed to be a moral perversion, a mental disorder, or a mortal sin. I remember that one of the more popular playground games of my childhood was called 'smear the queer' and it was played with great zeal and without a moment's thought to political correctness."

"On a darker level, that same worldview led to an environment of cruelty, violence, and self-loathing. It was but 1986 when the United States Supreme Court justified, on the basis of a 'millennia of moral teaching,' the imprisonment of gay men and lesbian women who engaged in consensual sexual acts."

Bombs to Wine in the Horse Heaven Hills

A portion of the south slope of the Horse Heaven Hills south of Prosser was for a time used as bombing range during WWII and into the 1950s. The use as a bombing range was discontinued and the land use switched to new range - for cattle and dry land wheat. Irrigation has converted the land yet again to vineyards and further south to orchards.

Notes on the Demise of a Port

John Stark at the Bellingham Herald did a story on how at least part of Bellingham's Port is failing as a port: bellinghams-waterway-cleanup-plan.

Overtime the Whatcom Waterway has silted in such that deep draft ships and not so deep draft barges are unable to dock where desired. A problem at many ports near large rivers. Silt entering the Bellingham Bay from the Nooksack River has partially filled in shore line areas that were previously dredged as harbor areas.

The silt deposits have effectively buried mercury contaminated sediments from past use of the Whatcom Waterway and Bellingham Bay as discharge points for mercury tainted wastewater from the former paper mill in Bellingham. The Port would prefer to leave as much of the buried mercury contaminated sediment as possible where it is. That policy is clearly at odds with some of the shippers that would like to use the waterway.

Mike Stoner, the Port of Bellingham Environmental Director notes in the Herald article that the waterway had been a small barge facility in the past and will remain so. He also noted that dredging  would delay the cleanup of the waterway years and would add a cost of $10 million dollars to the cleanup.

Clearly there is now a demand for a larger barge facility now and the Port is not providing an alternative. The demand for gravel or aggregate shipping in Bellingham should be expected to increase as the area gravel pits near the city are nearly exhausted and there are no other land based sources to replace them. The lack deep draft barge loading will be an added costs to road and construction projects  throughout Bellingham until barge shipping is improved.

In terms of the added costs and delays to cleanup, it should be pointed out that the Washington State Department of Ecology approved a cleanup that included dredging the entire Whatcom Waterway in 2002 - any delay 11 years on now has been purely the result of the Port of Bellingham's actions as the Port very purposely derailed that cleanup plan by moving to condemn the location where the dredged sediment would have been disposed of. I will add that the claims of increased cost of $10 million sounds  bad, but again the original cleanup plan approved by Ecology was estimated at $23 million. The Port of Bellingham's plan is over $100 million. Hence, costs concerns are by no means the driver of this Port turning its back on the very purpose it was supposedly created for.

I have previously posted rather obsessively posted on the cleanup schemes for the Whatcom Waterway:
 bellingham-bay-cleanup-planning-15 years on
bellingham-bay-cleanup-death-of-Alternative J
bellingham-waterway-and-bay-cleanup-Port-Alternative
mtca-funds-proposed-for-marina
bellingham-bay-cleanup-how-is-port's-cleanup-plan-doing
asb-to-marina-and-state-toxics-account

Elephant Seals

This picture is not from Washington State but the mainland shore of California. What is not captured in the image is the smell. Lots of urine!

This unexpected encounter adjacent to Highway 1 does cause some contemplation of our interactions with sea mammals. These must have represented a huge protein source at one time. Other predators must have been influenced as well. These seal were hunted later to near extinction and their presence on mainland beaches is relatively new behavior.

For regular readers, posting is limited and will be for a while. 

Slaughter Houses and Policy

The New York Times had an interesting editorial on slaughter houses awhile back:
support-your-local-slaughterhouse.

Whatcom County Council has been struggling with this issue mightily. The Council recently expanded the areas where slaughterhouses could be located with the idea of allowing small scale slaughterhouses for local meat processing. The process turned rather bumpy and has not yet been entirely resolved two-years-on as there are now appeals and the County Council with a different make-up is considering some adjustments to the rules (whatcomcounty/council/agendabills/ab2014-060b.pdf).  

As an exercise to try to appreciate the job of County Council try to read the ordinance and fully understand all its nuance. The one take-away regarding motivation is that there is only one USDA approved beef slaughter/packing facility north of King County open to the public (Finding of Fact 9)and that facility can only process 2,000 animals. Given Whatcom County's cattle population is 95,000 cattle.

My own following of this process the County has been going through is that in trying to do what should be considered a good thing got really strange fast and turned into a proxy policy wonk battle about Ag land, property rights, animal rights and a host of other afflictions. The County Planning Commission appointed by the Council to try to resolve these types of contentious issues before they get to the council managed to throw gasoline on the fire making the whole thing even more crazy.

The current council seems to be coalescing around a general concept and perhaps the problem will be resolved Tuesday. I wish them well.  

Not So Cuddly Otters

Sea otters, not to be confused with otters, were an important part of the early trading history history of the Pacific Northwest with first English traders and later, American and Spanish traders. The sea otter brought profound change to the Pacific Northwest.

I have seen river otters on numerous occasions while doing field work. It is tempting to assign anthropological values to them (river-otters-and-seal). But Dylan Mathews at Vox provides The Case Against Otters.

The Good and Bad of Parcel Search Tools

During my County Council Whatcom County presentation on geology hazards (HERE) I put up this slide at the very end regarding policy and geology hazards.

 

 

The one area I was critical of the county was regarding the county online property and parcel map search. Ralph Schwartz was in attendance and picked up on the issue (bellinghamherald.com/geologist-whatcom-parcel-map and bellinghamherald.com/whatcom-exec-goal-to-have-new-county-website).

I used Jefferson County as an example of a parcel search tool. 

Click this link http://www.co.jefferson.wa.us/assessors/parcel/ParcelSearch.asp and you get this:

Typing in the address or the tax number will take you to assessor data information about the property in question, but if you click on maps you get this page:

The page gives you a choice of maps. Click on the Critical Areas map and you get this:

 A county map with a tool bar and layers that can be turned on or off depending what your interested in. So if I turn on LiDAR towards the bottom of the layers list and zoom into an area I am interested in I get this on the Toandos Peninsula along the west shore of Hood Canal.

This great for geologists, but the images also help any perspective property owner or an owner wanting more information about the lay of the land. The north-south glacial striations can be seen as well as deeply incised ravines as well as some deep-seated landslide activity. The tool bar allows one to measure distances and click points to find the elevations.

If you prefer not having a bare earth image from the LiDAR you can click on an aerial image from several dates typically going back to the early 1990s. And if you want to see where streams might be located click that.

A forested landscape showing the location of the lots and streams including streams thought to have fish. Important information when in the early stages of thinking about developing a property.

But how about the geology hazards? Click off the aerial photo and click on Landslide Hazard and you get this:

Yellow is low landslide hazard, orange is medium and red is high. Green are lots where a landslide hazard has been identified. No color means the location is thought to not be in a landslide hazard.

The designations are not absolute. The map is meant to be a screening tool to alert someone that there may be an issue. There is no doubt that the screening tool could be improved, but the green zones indicate that as information becomes available the County tweaks the map. Those green lots have all had some sort of geology investigation or report or observation that there has been landslides at those sites. The landslide activity only impacted a portion of the properties.

In my own notes as a geologist I have already tweaked this map using LiDAR plus some on the ground work and would add a bit a red swatch across some of the yellow area.

Another layer to try is Parcel Tags. These are parcels that have got some attention and could be viewed as worth a careful look at the permits.

If you click on the lot with the "i" (information tool) you can get some information as to why a parcel was tagged.

In the case of one of the red parcels, the parcel was tagged as having a geotechnical report. The report places some constraints on the lot as to where the home can be located, how storm water is managed, septic location etc. The idea is the potential buyer can see the report'

The Jefferson County system is by no means perfect, but it allows property owners to be much better informed. The above example relates to a recent small project I did. i buyer was looking at a lot in the area and noted that there were red tagged lots with geotchnical reports. He called me because I had written one of the reports or two or three (kind of my niche area). He was already well informed and the fact that there was deep-seated translational landslide on the property he was interested in was not a surprise.

There are other very good parcel search tools. I have been using some for so long that I am not sure how easy they are to use as I have them kind of figured out. But I have always like the Jefferson system. Clallam has essentially the same program, but has even more information on the maps. King County I Map is very good and Thurston County has a nice system as well at least for my purposes. And yes, Whatcom is terrible as is Island.