Thursday, November 16, 2017

Deming Slide Complex Notes

In preparation for a field trip to see and view a few deep-seated bedrock landslides, I pulled up a lidar image of one of the roads we are heading up in order to view another slide. The route takes is into an area that appears to have some slide features as well as a rather fractured looking slope. 

Lidar image of south end of Sumas Mountain in Whatcom County
Nooksack River valley floor is in the bottom of image
Noted fluted landscape on the east portion of mountain that is a combination of glacial action combined with resistant sandstone beds of the Chuckanut Formation

Geology map of the area by Dragovich and others (1997)
Geologic Map and Interpreted Geologic History of the Kendall and Deming 7.5-minute Quadrangles, Western Whatcom County, Washington

Dragovich and others (1997) mapped an area between two distinct surface fractures as a landslide. However, the lidar imagery suggests the slide complex extends further west. A later map by Lapen (2000) included the larger slide area.

I have not assessed this slide complex, but did walk along the east limb of the slide on an unrelated assessment associated with a debris flow hazard. A stream flows within the fractured east edge of the slide exposing a dip slope surface of the east side of the slide complex. 



Complex topography and one one numerous mountainside deep bedrock failures to consider during our ventures and discussions.  

Wednesday, November 8, 2017

A Very Few Post Election Notes

Notes on Tuesday election results:

The issue I cared about was the Whatcom County sales tax for building a new jail. That tax failed with the "no" vote prevailing with over 57% opposed. This was a very satisfying win (my perspective). The amazing part is that nearly every elected official in Whatcom County was supporting the jail tax. But three of the the seven County Council members, Barry Buchanan, Ken Mann and Todd Donovan, voted against putting this ballot measure forward.

The real test of leadership will now commence. Can the County Sheriff, Executive and Prosecutor recognize that voters want to go in another direction with the County justice system than the one they advocated for. They are still the leaders on this issue. Those opposed to the jail can only express their views via voting. It is time for county leaders to take actions that reflect the direction of the voters.

Barry Buchanan likely won re election to the County Council. Not bad given that $100,000 was poured into this race by the Washington State Real Estate Association for his opponent.

In Vancouver, the Port race went to an anti oil terminal candidate despite industry money backing the pro terminal candidate.

Sunday, November 5, 2017

Music Sunday: Typhoon

A few years ago I saw Typhoon (http://wearetyphoon.com/)and have been a fan ever since. The Oregon based band has a set of shows after a long period of no tour dates. Looking forward to seeing them again and hearing their new Offerings.    

Thursday, November 2, 2017

Glacial Marine Drift in Northwest Washington

A significant portions of the lowlands of northwest Washington are underlain by glacial marine drift. To get a sense of how glacial marine drift gets deposited, a little satellite imagery provides a good overview.

Southern coast of Chile

Plumes of silt and clay are poured into the marine waters from nearby melting glacial ice.

Northwest Greenland

Another source of glacial marine sediment is from melting glacial ice floating on the sea surface. Ice bergs as well can provide sediment to the sea floor miles from the glacial front.

In northwest Washington, the glacial marine drift was deposited during the late stages of the last glacial period. The mass of thick glacial ice that was on the order of 5,000 feet thick in the area between 18,000 and 15,000 years ago had isostatically loaded the land surface such that the current land surface was hundreds of feet lower than the current elevation. 

As the ice thinned the area became inundated with sea water. Floating glacial ice on the water surface melted and dropped sediment onto the sea floor. Sediment also was delivered by plumes of sediment rich meltwater that entered into the shallow water from ice covered nearby upland areas. Much of the glacial marine drift is predominantly clayey silt but also includes drop stones and coarser sediment dropped out by the floating glacial ice. 

What the lower Skagit valley may have looked like when inundated with sea water. 

Ice would have been floating on the water and the ice margin on land would have been very nearby. Glacial marine drift covers areas from Marysville to the Canadian border and includes area in the San Juan Islands and near Port Townsend. The glacial marine drift is a predominant unit around Bellingham. 

Post glacial marine deposition, the land surface rapidly rebounded above sea level. 

DEM of Skagit Flats and Samish Flats with an upland area between
The upland area is where the Skagit Airport is located
This upland is underlain by clayey silt glacial marine drift

Post emergence, the upper glacial marine drift has undergone some compaction via wetting and drying, such that the upper layers of the glacial marine drift below the weathered top soil layer are very dense and compact. 

Very hard glacial marine drift. Note the drop stone pebble.
Also note haw the compaction process has led fractures within the drift

Areas where the unit has remained saturated such in long term year round wetlands or at depth below the year round groundwater level have not undergone wetting and drying compaction and remain very soft.

Very soft glacial marine drift in sample tube from geoprobe boring

The geotechnical properties of the marine drift differ from glacial till, and generally allow determination of the difference without the need for fossils. However, it is always fun to find fossil evidence to back up the interpretation.

Worm tubes removed from soil boring in glacial marine drift

Tuesday, October 31, 2017

Beckey Has Passed On

Via The Mountaineers Fred Beckey has left us (remembering-mountaineer-fred-beckey). I never met Fred Beckey personally, and I never categorized myself as a climber. But regardless I felt I had met Beckey. During another era I worked in the North Cascades and the three geologists I worked with had dogged eared copies of Becky's guide. At that time I viewed him as a guide to personal terror. He had ventured into extremely difficult terrain prior to our geology ventures and his guide books provided the descriptions on how to get to places that tested my nerves and fortitude.

A few years later I utilized his guide books to navigate into areas not for peak ascents but to explore the geology of a specific area in the North Cascades Range. I did take some pride in navigating an ascent approach within my own field area that even Becky described as an unpleasant route that he backed out of but still provided as an approach route option. The route was not some great climbing route, but was an absolutely miserable 5,000-foot ascent through thick"dog hair" Douglas fir to the base of a glacier where the alpine ascents began. My first attempt of the route ended in miserable retreat. The second time was completed successfully as a solo venture that include my longest stint of no other human interactions after reaching the edge of a the high glacial area below a string jagged Becky first ascent peaks.

While I have looked up to many of his first ascent peaks and routes, I was more impressed with the access routes he pioneered to even get near some of the North Cascade peaks. The challenge of the North Cascade climbing he pioneered was a mix of technical combined with very physically demanding approach routes into and through the deep valleys within the range.

Getting to the many of the North Cascades peaks Becky climbed takes passion and a physical fortitude few people possess. But pioneering these routes also took judgement - very good judgement. That judgment explains more than anything else how Becky survived so many of his adventures and led such a long life. He had the ability to read a landscape without guidance and I am struck by how many of his ventures took place through times when he was young and may not have known better and when he was experienced enough that he could have been fooled by arrogance.       

Sunday, October 29, 2017

GSA Talks Ice Sheet Grounding-Zone Wedges

The first half of last week, Sunday through Wednesday was taken up at the Geological Society of America meeting in Seattle. Hundreds of talks and presentations to choose from over a three day period. Deciding on which talks to attend was at times difficult. 

One of the early talks I went to was titled Sedimentary Processes at Ice Sheet Grounding-Zone Wedges: Examples From Antarctica and Washington State (U.S.A) (Demet and others, 2017). This talk had some practical applications to my own work on landslides.The talk was a brief version of Demet (2016) thesis work on some of the shoreline bluffs of Whidbey Island.

When the Puget ice lobe retreated the sea invaded Puget Sound and for a time the glacial front consisted of a front of grounded ice (ice in contact with the ground) and a sheet of floating ice. Demet and others (2017) recognized several locations where the grounding line may have been present on Whidbey Island as the ice retreat paused and suggests that the grounding line area became an area where there were some minor readvances of the ice sheet.


A few weeks ago I observed some highly distorted and complex glacial sediments along a steep shoreline bluff along the Strait of Juan de Fuca. Seeing deformed glacial units is not unusual, but the degree of deformation and the cross cutting relationships were perplexing. The area was a mix of glacial outwash, glacial tills and glacial marine drift that was not following the pattern of what is the more typical sequence of units. Understanding the units and just what units I was looking at was a critical component of assessing the potential bluff failure mechanisms. In particular, at this site the presence of poorly compacted glacial marine drift was of interest because it appears to be the cause of some of the larger scale failures that are present on portions of this particular bluff. 

The pattern of units appears to be consistent with the observations made by Demet and others (2017). Perhaps a more diligent comparison would be in order.

Saturday, October 21, 2017

Election Forum - Whatcom County Jail Tax

Jails are very much a part of the Washington landscape (had to get that in). Every county in the state has one as do many of the cities. The county jail is the leading edge of the United States criminal justice system. The jail is a big part of every County budget. Criminal justice and criminal justice spending is complex.

So for Whatcom-centric folks that are trying to decide how to vote the jail tax you can get a couple of perspectives here, but this conversation is at some level very much part of every community (Jail Woes). I am the Vote No Jail Tax person in this video. For a short cut version I have a few major points below.



Cost of the jail will be $250,000 per bed compared to Skagit County at $120,000 per bed. This puts the proposed Whatcom jail as one if not the most expensive jail per bed in the United States.

Tax proponents have stated that some of the tax money will be directed to incarceration reduction programs. There is no guarantee that will take place and the amount suggested is initially $500,000 per year. The amount will go to the jail construction will be $6,759,208 per year assuming the bonds to pay this amount over 30 years can be had at 4.5% and the jail come in on budget.

The existing jails were evaluated by a engineering firm and were found to be "structurally sound and in fair to good condition". They estimated that both jails could be upgraded and maintained at a cost of $32.4 million over a period of 20 years. The cost of the proposed jail will be $202 million over 30 years, and the $202 million assumes no future expansion.

The same engineering firm that reviewed the jail conditions asked the county if a portion of the existing low security jail be improved and hardened for medium security. The 'County officials' stated that the would have to have new public outreach and this was a nonstarter. The fact is the county never evaluated this option in a public manner nor any other options.

When the County did an EIS on the jail they only evaluated options 1) build the proposed jail or 2) don't build a new jail. Given that this project is by far the largest capitol project in the county with broad community impacts that will last generations and evaluating only 2 options is a poor way to make such a large decision. I testified to that during the EIS process.