Sunday, October 10, 2021

Malden, Washington Notes: Ice Age Flood Route

A bit over a year ago a wildfire burned much of Malden, Washington. Due to the extent of the destruction, the already tenuous economy of the small town and the very delayed National Major Disaster Declaration by the President, there have been follow up stories and takes on the fire and the aftermath (https://www.seattletimes.com/seattle-news/the-day-a-wildfire-took-malden/). Northwest Public Radio and Spokesman Review as well as Spokane area TV stations have continued to report on the town's effort at recovery.  

Malden Post Office before the fire

Malden is a bit off the usual routes; hence, I thought a little background on the landscape of Malden and the vicinity would be of use. I passed through Malden about a month before the fire and also on a trip to Rock Creek and Bonnie Lake (bonnie-lake-precambrian-schist). On that earlier trip I paused at the Post office (above picture). 

Malden is located in Pine Creek valley in the norther part of the Palouse. J Harlen Bretz (1923) recognized that the Pine Creek valley was a pre existing valley that was further eroded by ice age floods, "The valley during this episode in its history was but a channel. The glacial stream filled it from side to side for a depth of tens of feet. This is shown a few miles above Malden, where the stream flooded over a low shoulder of basalt, cutting a channel in the rock at least 40 feet deep, though the main valley alongside was a wide open and received gravel deposits." 

Map of Spokane Flood routes from Bretz (1925)

Flood water spillway from upper Latah Creek into the North Fork of Pine Creek (Bretz, 1923)

The ice age floods that Bretz was describing were the result of water spilling over from Latah Creek. The Okanogan ice lobe dammed the Columbia River forming glacial Lake Columbia in the backed up the Columbia River. The lake extended up the Spokane River and Latah Creek, a tributary stream to the Spokane River. When the ice dam at that formed ice age Lake Missoula collapsed, the flood waters surged out of the rapidly draining lake and into the Spokane area and into Lake Columbia. The sudden influx of a massive surge of water resulted in Lake Columbia overtopping at numerous low divides to the south. One big spill way is the Cheney-Palouse scabland tract southwest of Spokane. Interstate 90 passes through part of the tract. But some water backed up Latah Creek and spilled over a divide into the Pine Creek Valley.  

DEM of spillway from Latah Creek into Pine Creek

The ice age flood features in Pine Creek are a bit more subtle than the raw wide stripping of soil that took place in the very broad Cheney-Palouse route. But the features were noticeable to Bretz and are not consistent with the other valleys that were not flood rotes that pass through the Palouse landscape. 

Another factor that softens the flood features in the Pine Creek Valley is that this flood route has a bit wetter climate than those to the west and the valley has more areas of pine -- hence the name Pine Creek. More on that on a future post.    
   


Wednesday, September 8, 2021

Pyrite in the Gravel

One of the sources of crushed gravel in Skagit County is a rock quarry. The quarry has mined large blocks of rock for levy projects, but the process of breaking the large intact blocks of rocks creates smaller rock. Hence a side product is angular crushed rock gravel for driveways and parking areas. The angular rock along with the fines within the crushed material forms a hard drive and parking surface. 

Crushed rock gravel parking area

Walking across one of these driveway areas on a moonlit night I noted remarkably bright spots in the gravel. My geology brain clicked in and I recalled the likely source of the gravel being a rock quarry excavated into some altered ocean floor igneous gabbro. The ocean floor rocks are a Jurassic age accreted terrain slab of ocean floor. Hot fluids flowing through and old ocean floor precipitated minerals. The bright spots I was seeing in the gravel was moonlight reflecting off of the very smooth surfaces of cubic pyrite minerals.       

A larger pyrite mineral - most are much smaller
I spotted this during the day when a very bright reflection struck my eye 

Pyrite is an iron sulfide mineral and is pretty common secondary mineral. Its breakdown via weathering in pyrite rich crushed mining tailings is a source of acid mine drainage. Its presence in some limestone deposits or the rock aggregates mixed into concrete is detrimental as the pyrite breaks down the sulfur released will form acids that will damage wiring, pipes or other metal in the concrete and can also form hydrogen sulfide foul odors.  

 

Tuesday, September 7, 2021

Ground Wasp Hazard Season

Field work hazards vary depending on where one is working and the time of year. In September in western Washington as well as elsewhere a hazard that I try to be alert for is ground wasp nests. 

Yellowjacket nest

The life cycle of the wasps is such that the nests become very large in late summer and the nest becomes populated with adult wasps that will readily defend the nest. Fortunately the wasps rarely sting when passing near the nest, but accidently stepping into or on a nest in late summer is a hazard.

I managed to avoid stepping into any nests last summer and thus far have a avoided doing so this late summer. Last week a client helpfully alerted me to a nest along a survey path cut through the brush prior to my field venture. I noted the small fast flying wasps near the nest shown above before spotting the entrance. 

My last encounter with stepping into a nest was on a very steep slope. The usual fast escape via running was impeded by the slope conditions which meant I had to crawl up the steep slope as fast as I could and likely further disturbed the nest as I began my escape. Once I reached the top of the slope, I was able to run, but continued to be stung. The next step was to shed my shirt and pants as fast as I could. Wasps release odors when they sting which stimulates additional stings and additional wasps to attack. My car was not far away and I had extra clothes (a typical habit as I often get wet doing field work). Even a half hour after my encounter there were still wasps stinging my dropped shirt.  


 

Wednesday, August 18, 2021

A Smoke Eclipse from the Schneider Spring Fire

I had a couple of central Washington projects and was relieved that the approaching cool front cleared the smoke away. The western air flow was evident as I approached the Columbia River gorge from the high plains of central Oregon.  

Lenticular clouds formed downwind of Mount Adams

However, the clearing of the stagnant air and smoke does not mean the fires are not still active. The Schneider Springs Fire (HERE) created a huge plume of smoke and cloud.

Plume of smoke and cloud above Schneider Springs Fire viewed from Yakima

In the Yakima Canyon between Selah and Ellensburg the plume of smoke passing overhead eclipsed the sunlight cooling temperatures in the canyon. 

North end of the Yakima Canyon with the Stewart Range in the distance and thick smoke overhead 

Dim evening like light south of Ellensburg

Smoke plume downwind darkening the Wenatchee Mountains

View to the west from Highway 10 northwest of Ellensburg

About half way between Ellensburg and Cle Elum I got back into the sun. 

Smoke plume and wind turbines northwest of Ellensburg

It was nice to have the smoke pass over and not breath it. There was some ash fall of white burnt fir needles while I was working in the Yakima Canyon, but no smoke, no hot sun and temperatures in the mid 80s made the work a lot easier than expected.



Thursday, August 12, 2021

Back From Halle (Saale)

I returned from a two month break. I did some remote work while gone, but am now back on field work and follow up writing ventures. I appreciated the support of my associates at Stratum Group that worked more than diligently in my extended absence as well as dealing with the issues of working in and through the time of covid and the preparations for changes in Stratum Group.  

For two months one of my views in Halle (Saale) was this wall across the street from where I was staying. I sat in a chair at the window and contemplated the odd assortment of rock blocks and obvious multiple periods of window openings. 

The building is old by the Washington State standards that I am used to. As best as I was able to piece together the history, the initial structure dated back to the 1200s, but it may be even older. I suspect it has had multiple periods of use and vacancy - pictures from the 1980s showed that the roof was missing. An associated building had been badly damaged by one of Napoleon's armies. 

The rock blocks are mostly local volcanic sandstone and volcanic rocks of Permian age. 

Geology is the basis of Halle's history; the Market Square Fault cuts through the city and that fault caused salt water springs to issue from the ground on the west side of the city. The salt was a very valuable commodity. The fault is given credit in the main square of the city next to the drinking fountain. 


The English side of the marker made my translation easy

As noted on the marker salt was utilized from the site at least 5,000 years ago. Approximately 20 miles to the west there is a Paleolithic site that dates back 400,000 years. People were here for a long time compared to my homeland in Washington. 

I returned home this last week with only a brief view of scenery on the flight back as most of the flight was over clouds.

Near to coast of Greenland

I miss my night shift and walk-about companion during my stay in Halle (Salle).  

At the river lock on one of many walk-about adventures 

Saturday, July 17, 2021

Flood Plain Hazards of Open Pit Mines

I missed the historic heatwave in the Pacific Northwest as I am currently in Germany. I am not in the zone that has been impacted and terrible floods, but the event is 'close to home' so to speak. Dave Petley (HERE) noted a river in the west of Germany that broke out of its course and flowed into an open pit coal mine in Inden. 


Dave noted the river course into the mine followed an old channel. That channel was the former river channel up until about 15 years ago. The channel was blocked and the river was rerouted in a long circuitous route around the mine.

Blue line shows river route around open pit coal mine

Blue line showing most recent river route and red line showing former path

Although the flooding of the coal mine was impressive, a more dangerous flood into an open pit mine took place a few miles away at Blessem. NPR led their story on the flooding with an image that had a caption about an entire field collapsing due to flooding (npr.org/germany-belgium-flooding). 

  (picture alliance/dpa/Rhein-Erft-Kreis | Rhein-Erft-Kreis) The image shows very rapid headward erosion as floodwaters drain off the flood plain down a steep gradient. The source of that gradient was and open pit sand and gravel mine. 

Same site looking toward the mine  (picture alliance/dpa/Rhein-Erft-Kreis | Rhein-Erft-Kreis)

Red line is approximate extent of area eroded. The yellow line is my measurement of the headward erosion distance of 850 feet.

The headward erosion continued after the above image and expanded into the town taking out a number of buildings. 
 

In this case it appears that flood waters on the flood plain began to flow rapidly towards the pit as the water drained towards the low area of the sand and gravel mine. While gentle slope wide flood plains have flood risk and potential hazards associated with channel movement. The rapid erosion associated with flood water flows into open pit mines is well demonstrated at this site.    

Friday, July 9, 2021

Notes on Heatwave Global Warming Attribution

Phillips and others (2021) have taken a rapid assessment run at global warming attribution of the 2021 Pacific Northwest heat event. A summary of key points is provided at the beginning of the paper. Two points stand out:

The observed temperatures were so extreme that they lie far outside the range of historically observed temperatures. This makes it hard to quantify with confidence how rare the event was. In the most realistic statistical analysis the event is estimated to be about a 1 in 1000 year event in today’s climate.

This simply emphasizes what most long-term Pacific Northwest residences felt - this event was very far from what anyone expects for northwest summers. For those that experienced the event, you have a story to tell. But this was more than a remarkable event for the Pacific Northwest; Christopher Burt author of Extreme Weather stated “This is the most anomalous regional extreme heat event to occur anywhere on Earth since temperature records began. Nothing can compare.”   So for those that went through the event (I missed it), you can say you went through a world historic weather event.

There are two possible sources of this extreme jump in peak temperatures. The first is that this is a very low probability event, even in the current climate which already includes about 1.2°C of global warming -- the statistical equivalent of really bad luck, albeit aggravated by climate change. The second option is that nonlinear interactions in the climate have substantially increased the probability of such extreme heat, much beyond the gradual increase in heat extremes that has been observed up to now. We need to investigate the second possibility further, although we note the climate models do not show it. All numbers below assume that the heatwave was a very low probability event that was not caused by new nonlinearities. 

Under the first possible source, that the event was a very low probability event, global warming additive attribution pushes the temperature upward some amount more. Phillips and others (2021) note that the observed annual maximum daily temperatures in the Pacific Northwest trend is approximately 2 times the global temperature trend. So regardless of the event being rare, our heatwave temperatures have been trending upward at a greater rate than the global temperature trend as well as our local temperature trend.

Figure 4 b) Annual maximum of the index series with a 10-yr running mean (green line)

Burt noted in 2017 that Seattle has had 122 record high temperatures since 2010 compared to 19 record low temperatures and Salem has had 98 record highs compared to only 11 record lows.  

Another potential added source of heat is the trend of 500hPa height associated with a warming expanding atmosphere (Christidis and Stott ,2015). 


Phillips and others (2021) also suggest a source of added heat may be from persistent drought in the west leading to higher temperatures.


Given the circulation associated with major heatwaves in the Pacific Northwest, drought and enhanced heating in the southwest will be a contributing factor as hot air from that region descends into the lower elevation areas of eastern Washington and across the Cascades to the west side. 

Phillips and others (2021) suggest that global warming pushed the temperatures about 2°C warmer than they otherwise would have been. 

The other question or cause would be the potential that the heatwave was caused by a 'nonlinear' factor related to global warming. Phillips and others (2021) do not attribute this event to a nonlinear event such as a wavy stalled jet stream, but do give it a brief discussion and suggest further analysis. 'Stuck' jet streams or omega blocks are a point of some debate in climate science. 

I would note that this attribution paper was a bit narrow. John Pollack (HERE) notes that this event was preceded by two western US heatwaves of similar pattern, but to the south in June that set records including tying the all time high temperature in Palm Springs, CA of 123 F. Those events likely provided some additional heat charge to the third high pressure event centered in south British Columbia with southeast flow of air coming up from the southwest U.S into the Pacific Northwest. And the pattern of high pressure heatwaves of long duration is continuing. From the National Weather Service: The current forecast for Las Vegas is just below the all-time record of 117.  This is the fourth western US major/record breaking heatwave in the past month.