Sheep in the Vineyard

I had a request for the use of a photograph I posted of the Wallula Gap area. The photo is to be used on a book regarding the Columbia River Treaty. I took the picture at Wallula Vineyards, a remarkable vineyard of that includes a variety of wine grapes. The vineyard has a bit over 800 feet of elevation difference within the vineyard and soils range from wind blown loess, rocky basalt terraces with thin soils and Missoula Flood gravels. The vineyard is irrigated via water pumped up from the Columbia River.

Tracking down the original photograph and other potential pictures I came across a number of other photos from my time at the vineyard. Lots of cool science going on throughout the vineyards including some interesting experimentation. For one variety of grape grown on trellises sheep are used to control grass height and weeds and to maintain the vine growth direction by trimming off low growing shoots. The process turns grass material into readily available fertilizer and greatly reduces labor. The vineyard managers are working to breed small sheep to control the reach of the sheep. 

Typhoon

Bit heavy on work load of late and other stuff

I am really pulling for this band. It really is a band.

Asbestos Sediment Piles at Swift Creek

I was out in the Everson/Nooksack area and stopped by the lower reach of Swift Creek. Whatcom County recently purchased a property adjacent to the creek in part to have a location to place dredged sediment from the creek in an effort to keep a road open. The following picture is the view of the most recent sediment pile from the former home site.

Dredged sediment near Swift Creek east of Nooksack, WA

The juxtaposition of the swing set and a large pile of asbestos containing silt and sand suggests that this purchase of land avoided more than simply a county stream crossing problem.

The volume of asbestos laden sediment that has been pile up along the creek the past few years is at a remarkable scale. The sediment will continue to come down the creek. 

Ridges of dredged sediment along Swift Creek viewed from South Pass Road

Swift Creek from Oat Cole Road bridge 

Cloudy water from very fine grained clay

Not all of the sediment is deposited and then dredged from the creek. Fine silt and clay continues to be carried downstream into the very slow meandering Sumas River. The Sumas flows north into Canada where the silt and clay poses problems to drainage in the farm land of the lower Sumas valley. The Canadian section of the Sumas River was formerly a lake and the maintenance of that lake requires pumping. The sediment loads cause problems for the pumps as well as the overall drainage systems of this high quality farm land.

View of Swift Creek and Sumas Mountain, the source of the asbestos sediment within the Swift Creek landslide



Mima Mound Cross-Sections

I had some work last week in southwest Washington and took a little side trip to check out some prairies. I did the same thing during another trip this winter. Both trips involved getting very wet and very cold not only in my paid work but in my efforts to learn a little bit about this landscape that more typically is passed through on Interstate 5 with few or no stops. But on both trips I did get to see cross-sections of Mima Mounds. The first was an intentional cutting into a mound on the Mima Prairie that both Dave Tucker and Pat Pringle had alerted me to. 

Mima mound conveniently cut through showing the very thick organic soil (black) over non organic (tan) glacial outwash

Odd pocket of non organic soil surrounded by organic soil

Closer view of topsoil contact and the poorly sorted sediment

I checked out the pebbles to see the general makeup of the sediment. This area is a little outside my usual haunts so I am not sure what is typical glacial outwash composition in this area. Definitely saw andesite suggesting a Cascade volcanic source, but also saw greenstone and granite. Too nasty to site and do careful point counts. 

Purply andesite pebble

Metamorphic and granite pebbles

Back in January I spotted a cut through mound at Rocky Prairie. At this site the Douglas fir were invading the prairie.

Douglas fir capped mound cut by road

Same over thick organic layer of mixed organic silts and pebbles

I had a couple of theories regarding the mounds that I wanted to test out. I successfuly tested my theories. The theories failed the tests. More on the mounds at some future date.

Woodson Landslides

While going over aerial images of landslides in northwest Oregon and southwest Washington I spotted a set of landslides as I scrolled from one research/project area to another. The December 2007 storm that impacted northwest Oregon and southwest Washington caused a slide that closed US Highway 30 between Portland and Astoria. Several landslides and floods of debris and water impacted a the hamlet of Woodson, Oregon during the storm. Approximately a week later, a much larger slide and resulting debris poured down the mountainside closing the highway and destroying homes. No one was killed as there was a warning issued regarding the pending failure.

Beyond my own work on some slide damaged sites in northeast Oregon from that storm, I only knew that the slide associated with the highway closure was related to an old road via the news. The Oregon Department of Forestry (ODF) did a forensic-like investigation of the landslides and events that led up to the slides.

ODF_Rpt_07_Debris_Flow_Eilertsen_Crk_Woodson.pdf and
http://www.oregon.gov/ODF/docs/Geoscience_Rpt_07_Debris_Flow_Eilertsen_Crk_Woodson.pdf

The studies are well detailed and contain great images of the slide sites and explains as well as possible the sequence of slide events as well as the underlying geology and history of slides in the area. Within the past year fairly good resolution images have been released showing many of the landslide areas. I marked up some of the images of the Woodson slide area.

Aerial of Woodson area showing some of the 2007 landslide locations and steep drainage

This was not the first time that slides had impacted the Woodson site. Woodson is located at the base of a steep mountain slope with steep incised drainages. And the December 2007 storm packed a lot of rain over a short time. It was an intense rainfall event and thousands of landslides took place in southwest Washington and a lesser but still significant damaging slides took place in northwest Oregon.

Slides at upper Olsen Creek above Woodson

As can be seen in the images, multiple slides took place above Woodson. Residents indicated that multiple surges of flood water came down the mountainside during the storm. In the case of Olsen Creek, there were several small shallow slides within the headwall area of the creek drainage. As the slide material flows down the drainage it picks up debris and bulks up as it heads down the creek ravine.

Source area of large slide

The really big slide that impacted Woodson took place nearly a week after the storm. Two slides took place in the headwater area: one was a shallow surface failure associated with an old deep-seated landslide, and the second was associated with a reactivated deep-seated slide. These slides took place during the storm, but the material from these slides did not reach the bottom of the hill during the storm event. The slides path down the drainage was blocked by an old forest railroad grade. The railroad had originally been constructed as a trestle across the creek, but was later filled such that it was a 60-foot high embankment with a couple of culvert pipes passing underneath. The slides plugged the culverts and the loose fill embankment tuned into a temporary dam that lasted about one week. When the embankment collapsed a slurry of mud and logs poured down to Woodson. Fortunately, this potential trouble spot was recognized before the failure took place and residences were evacuated.

Geologists will readily say that if you have steep mountain slopes that occasionally get whacked with big rain fall events there will be landslides. Beyond that landslides and how to deal with this risk moves into the policy arena and politics as well.

One of the ODF papers includes a section at the end with recommendations. One recommendation was regarding development regulations. Despite a history of debris flows at this site and other nearby sites, there were no development regulations regarding building in these obvious geologic hazardous areas. For the most part, Washington State counties recognize geology hazards such as these.

The ODF report had some other recommendations as well and discusses the dilemma of managing large tracts of steep forest land for timber harvests versus public safety. What was not mentioned in the recommendations was fish, but that may be due to these streams not being salmon bearing.

Southwest Washington Prairie Camas and Strawberries

I had some work in southwest Washington the past few couple of days. Very wet and cold. There is not much rain shadow effect in that area and hence the rain was a bit heavy and it was windy with temperatures in the 40s. Despite the cold and wet I did stop by one of the southwest Washington prairies prairies-and-puget-ice-lobe.

Blue camas

Strawberries

The southwest Washington prairies have shrunk over the past 200 years, but were at one time utilized heavily by First Nations peoples for camas harvest, strawberries and a variety of other edible plants as well as grazing land for deer and elk indian-population-camas-and-prairie. I stopped at Mima Prairie last fall geologic-pilgrimage-mima-mounds and visited Rocky Prairie this last winter. While passing by the prairie pictured above I stopped to check out the spring flowers despite my semi pickled condition from filed work in the rain. It would be nice to enjoy this prairie in spring sunshine, but no luck this time. Or better yet experience the strawberries as Charles Wilkes did during his passing through the area in the 1841.

Imbricate Bedding and Frisbee Cobbles

I was walking along a cobble river bar and started noting the subtle alignment of cobbles on the surface. It is subtle and I found it hard to capture through a picture, but what I was observing was imbricate bedding.

Subtle alignment of cobbles

Imbricate bedding (Wikipedia)

Seeing this alignment got me thinking about measuring clasts in metamorphic conglomerate rocks. I spent a fair bit of time measuring and recording x, y, and z axis of cobbles in an attempt to determine strain on a past project. The first place I did this the rock was highly stretched with cobbles taking on an almost New York hot dog shape. But at another site many of the cobbles appeared flattened. And keep in mind finding metamorphic cobbles embedded in a formation where all three axis can be measured is not very easy. In looking at the cobbles I was traversing, I began wondering about the statistical significance of those measurements in particular given that initial roundness ought not to be assumed.

The above cobble in a metamorphic rock would give the impression of flattening strain.

Besides measuring strain, though the original alignment of non round cobbles like the one above can be used to determine flow direction. I have only applied this approach once on a project involving a gravel mine deposit.

Not only cobbles show imbricate bedding.