City Creek Nature Notes – Salt Lake City

February 27, 2017

February 27th

Filed under: Pollution, Weather — canopus56 @ 9:15 pm

Thin Air

5:00 p.m. Another day of snow whitens the canyon.

Jogging in the canyon is an antidote to depression. It infuses oxygen into and restores the brain, calms the body, and returns perspective. For some time based on popular science reporting, I had thought that the lower atmospheric pressure contributed to mild hypoxia that might induce feeling blue. Atmosphere decreases in density as elevation increases. A standard barometric equation indicates that Salt Lake City and the canyon should have 86% of the standard atmospheric pressure at sea level, or about 26 inches of mercury as opposed to 29.92 inches of mercury at sea level, and this is consistent with reported weather data (NOAA).

After leaving the canyon today, I look for the articles underlying the mild hypoxia hypothesis. In 2011, Kim at the University of Utah and colleagues statistically associated increasing altitude with the risk of suicide by examining suicides in 20 counties at altitudes between sea level and 11,500 feet (Kim). Salt Lake City is at approximately 4,300 feet in elevation. Relying on that the coefficient of correlation between altitude and suicide was positive, they concluded that less air was a significant risk factor for suicide. However, the coefficient of correlation was only 0.51, little better than chance; but, the standards of proving epidemiological causation is not the same as in mathematics. In 2015, Kaneka at the University of Utah and colleagues in a controlled experiment demonstrated a physical causal connection between low air pressure and depression by raising rats in hypobaric chambers (Kaneka). But, depression was only seen in female and not male rats, and this indicates the need for more research.

Air pollution, including particulate matter, is also believed to cause depression. In 2015, Bakian at colleagues at the University of Utah compared Salt Lake Valley suicide data for 2000-2011, stratified by polluted and non-polluted season (Bakian). They found that the relative risk of suicide two days after heavy spring inversions of PM2.5 was 1.20 as compared to other seasons. The relative risk of suicide three days after spring and fall inversions with high levels of gaseous nitrogen dioxide (NO2) was 1.35. Although not measuring mood, in 2012, Beard and colleagues at the University of Utah found that winter time inversions with high PM2.5 levels were associated with higher levels of emergency room visits for asthma (Beard).

By jogging in the canyon, my breathing takes in more harmful pollutants, but at a reduced level than I would receive by jogging in the valley. But the adverse effects of those pollutants are offset by the health benefits of taking in more oxygen.

In Thoreau’s “Journal” on February 27th, 1853, he notes how easily squirrels can open cones, while people cannot. He opens a pine cone by storing it in a drawer.

On February 27th, 1894, an employee of the Waterworks Department reported seeing a mountain lion in City Creek Canyon. City Councilperson Newell noted other mountain lions had been seen, and he suggested that the City authorize a hunting party to go into the canyon and “kill off the man eaters” (Deseret Evening News).


February 26, 2017

February 26th

Filed under: Pollution — canopus56 @ 9:40 pm

Escaping Bad Air

8:00 p.m. Just a short half-mile jog today in a twilight canyon. The enveloping dark and solitude are welcome. They allow me to concentrate on the physicality of running, on form, and on sensation of rhythm.

The air is clear today, and the valley and canyon have passed the worst of the winter air pollution inversion days. On previous days I have noted escaping to the canyon and away from the inversion air pollution layer that covers the lower city (Jan. 5th, Jan. 8th, Feb. 1st, Feb. 15th). That there is less pollution at higher elevations is evident by the visual difference of the atmosphere between the city and the canyon beyond mile 1.0, but scientific studies also support my impression.

In 2010, Silcox at the University of Utah and colleagues installed a series of air quality monitors along a transect line from the William Browning Building at the University of Utah to a ridgeline between City Creek Canyon and the Avenues. The highest monitor was at highest point of the ridgeline visible to the southwest from milepost 1.5 in the canyon. Silcox et al monitored PM2.5 particulate matter during January and February inversions, and they found during the heaviest inversion pollution events there was about a 50 percent reduction in PM2.5 levels between the elevation of the Salt Lake City Airport near 4265 feet above sea level (1300 meters) and the highest station on the ridgeline near 5900 feet in elevation (1800 meters). Since 2010, other vertical pollution gradient monitoring efforts began. The first by the John Sohl’s HARBOR group from Weber State University involves releasing weather balloons to an altitude of 500 feet above the surface at the Salt Lake City International Airport (Mountain Meteorology Group, 2017a) and the second by Lareau and colleagues at the University of Utah involves laser measurement of the density of the air (Lareau et al; Mountain Meteorology Group, 2017b). In January and February, 2017, the Division is undertaking a vertical pollution study using and airplane to fly through the inversion layer to collect physical samples (Utah DEQ, 2017). On a daily, real-time basis, the most useable source for a vertical air PM2.5 concentration is a network of less accurate citizen-science air monitoring stations, Purple Air. That network typically shows a gradient of reduced PM2.5 pollution from the valley to stations on the high Ensign Peak and Avenues benches and for one station in Emigration Canyon (Purple Air) (Personal observation).

All of these sources indicate that by jogging in the canyon, I am reducing my breathe intake of particulate matter pollution as compared to the valley, but perhaps by not so much as I estimate subjectively by just looking at the air.

February 25th

Filed under: Pollution — canopus56 @ 9:38 pm

Heightened Senses

5:00 p.m. Despite the low temperature, about ten strolling couples and runners traverse the lower canyon. The brisk air is refreshing and clears the mind. Modern life is a continual bombardment and over stimulation of the senses. Car noise, traffic, noxious smells, trash, and the continual distraction of advertisements and information dulls both the mind and the senses. My body has learned over the years to automatically dull the mind and to reduce the sensitively of the senses. My jogs and walks in the canyon reverses those effects, and during these walks senses reawaken. In the City, the smell of people, except for the most offensive body odors or the over perfumed, is not noticed. As my sense of smell heightens this evening, I can smell each individual person as they pass. This gives me a glimpse into how blind persons experience the world.

In Thoreau’s “Journal” on February 25th, 1859, he hears a nuthatch and see the tracks of skunks.

On February 25th, 1910, resident A. M. Pendleton recommended the planting of a cultivar, the English walnut, in City Creek Canyon and throughout the rest of the city (Salt Lake Tribune). This would have created an English style managed landscape “forest” in the canyon as currently appears at Liberty Park in the city.

February 24th

Filed under: Venus, Weather — canopus56 @ 9:21 pm

Seeing Flood and Drought Years

External Link to Image

Source: Harris 1942 at p. 53.

5:30 p.m. The canyon recovers slowly from yesterday’s storm and the abrupt turn back into winter. No birds are heard or seen. All has returned to frozen sleep. People are gone because of this echo in low temperatures, and once again, I have the canyon to myself. With the breath of spring earlier this weak, my body rebels against the cold. Although temperatures are not as low as in early January, it feels colder, and this illustrates how cold is as much as matter of perception as fact. Brilliant Venus, which a month ago was centered on the road while jogging down-canyon at dusk, now shines in the southwest sky as it out-runs the Earth on another turn around the Sun.

Such daily large variations between drought and heavy precipitation and heat and cold repeat in Utah’s and the canyon’s annual weather patterns. For the nine years between 1869 and 1877, City Creek flooded the city four times. There is a tree stump in picnic site 3. The original tree was perhaps a cottonwood. Examining and photographing the stump, I notice a pattern in the rings. A wider set of rings is bracketed by two sets of smaller spaced rings. The Wasatch Front Mountains and its valleys are an arid, drought region that are punctuated by years of extreme precipitation, snowfall and spring flooding. Weather records show a series of peak snow years followed by City Creek flooding the city. Perhaps the wider rings correspond to those wet years near 1870.

With respect to these drought and flood cycles, An old report summarizing the first one-hundred years of the Metropolitan Water District of Salt Lake City contains a graph that records these widely varying annual fluctuations between drought and flood. (Harris at p. 53, “Relation between Water Development and Population and Precipitation”). The graph illustrates how the growth of population, droughts and floods relate to plans and improvements to increase utilization of the canyon’s water. A twelve year oscillation between drought and flood, coupled with increasing population, drove the City’s expansion of water infrastructure between 1874 and 1942. An initial Euro-American colonist population in 1850 of 5,000 caused the first utilization of City Creek as a stream fed water source that ran as two ditches on the either side of Main Street (id, p. 4). After a flood cycle and a drought cycle ending in 1880 and a population increase to 20,000, the City brought water from Utah Lake via the 20 mile long Jordan Canal and it built initial holding tanks in and improved the stream channel of the City Creek to increase its flows. In 1890, after years of extended drought and a population expansion to 40,000,the City to built a reservoir in Parley’s Canyon at Sentinel Rock and drilled tunnels in City Creek to increase the flow from springs. After the next flood and drought cycle ending around 1900 coupled with a population increase to 50,000, the City obtained more water rights from Big and Little Cottonwood Canyon. After floods ending in 1910, an extended drought through 1915 and a population increase to 110,000, the City built reservoirs in Big and Little Cottonwood Canyons and the 5,000,000 gallon reservoir at Pleasant Valley of City Creek Canyon. After a flood cycle in the 1920s and a severe drought in the 1930s, together with a population increase to 150,000, the City formed a regional water district and began construction of a massive water reservoir system on the eastern or backside of the Wasatch Front Mountain Range. Water was transported between hydrologic basins through a series of underground tunnels, some as long as 12 miles.

Other drought cycles in the 1960s and 1970s, along with legal water rights concerns, gave birth to the Utah Central Project – a billion dollar series of dams and underground diversion tunnels from the Unita Basin about one-hundred miles away and the expansion of the Deer Creek reservoir and construction of the Jordanelle Dam. The Utah Central Project started delivering about 120,000 more acre-feet of water to Salt Lake County in 2007. The delivery of more water resulted in a massive construction boom on less expensive land in Salt Lake County that continues until today, and from 2014 to 2017, that construction boom has penetrated Salt Lake City limits in the form of box-like, high-density apartments. The increased population resulted in higher use of the canyon for hiking, running and bicycling that I have seen this season.

In Thoreau’s “Journal” on February 24th, 1854, he observes nuthatches, chickadees, and partridges. The partridges are feeding on lambkill shoots and blueberry bushes. On February 24th, 1857 he sees bluebirds and skunk tracks. On February 24th, 1858, he examines colors in the bark of the barberry bush.

February 23, 2017

February 23rd

Filed under: People, Seasons — canopus56 @ 11:05 pm

The Unicyclist and the Umbrella

7:00 p.m. King winter has returned. Temperatures have dropped into the mid-twenties and overnight and throughout the day, it has been snowing on and off. In the battle between winter and spring, winter shows of all his forms of snow in a few short hours. There is fluff powder, intense storms of graupel, slush, and light snow that melts on contact. In the canyon, there is a quarter-inch of light snow on the road, and that and the light falling snow has kept everyone away. Complete solitude returns as I jog up with the sound of crunching snow under my feet and sprays of tossed snow emanating from my toes. The stoneflies, other insects, and squirrels have returned shelter under rocks and in burrows. The newly formed grass shoots will be injured, but all this will quickly melt tomorrow. The air is thick and fog like from the twilight and falling snow.

Returning down canyon, out of the mist, a unicyclist appears, riding in the opposite up-canyon direction while holding an umbrella in one hand and a briefcase in another comes. For people who work downtown or live in the nearby Avenues or Capitol Hill area, he is a familiar site. He is a well known attorney who gets his exercise by commuting between work and home by unicycle. He is taking an long detour on his way home and his presence brings a welcome whimsy to the canyon. I marvel that he is able to maintain balance and sufficient traction to ride uphill through the snow.

In Thoreau’s “Journal” on February 23rd, 1854, he describes how a snow storm is forming sculptured drifts. On February 23, 1857, he sees two yellow-spotted tortoises. He sees other signs of spring: a frog and sap flowing from a red maple tree. On February 23, 1859, he sees eight to ten bluebirds. On February 23, 1860, he records a temperature of 58 degrees, and he notes that green shoots of several species are growing.

February 22, 2017

February 22nd

Tree Trunks

4:00 p.m. This a year of extremes: on February 21st, the temperature was sixty-six degrees and yesterday and last night and today, after raining for almost ten hours, the temperature has dropped to thirty-three degrees Fahrenheit. As I enter the canyon, it is snowing, but this is light snow that turns to water when it touches any physical object. The high ridgelines and Pleasant Valley are covered in snow dust, perhaps one-eight of an inch thick, but it will not last. This is the second sign of the coming spring now one month away: The battle between spring overtaking winter (September 22nd) has begun. There are other signs. At Guardhouse Gate, I see my first, fat and healthy Rock squirrel of the season. It runs across the road and is busily inspecting bushes for fresh buds. The constant rain has driven three earthworms on to the road, even though temperatures are freezing. High on the ridgeline near mile 1.1, I see my first mule deer in over a week. Even at this distance, it is skittish; it tentatively comes out of a copse, feeds, and then retreats for cover.

The lichens and mosses are the most responsive to the hours of light rain. Everywhere the orange, yellow and green colors of lichen and mosses have deepened, and a few trees become vibrant flames amongst winter’s brown, grey and white. Black cankers on tree branches that normally turn to dust when touched have become plump, fat and solid with water. It is the time of year for the simplest organisms, for the earliest life.

Tree trunks have so many varieties of forms. Above picnic site 6, some trees are like brothers and sisters. The trunks of two 4 inch diameter immature river birches intertwine in a playful embrace, and they spring from a common root. Next to the River birch, are three immature Box Elder trunks that also rise from the same root. These stand tall and vertical like two brothers. At and down-canyon of picnic site 6, large Mountain cottonwoods have large bulbous galls on their lower trunks, and this is evidence of old attacks by insects, bacteria, and fungi. Other trees in the lower canyon have partially or completely succumbed to age and disease. At picnic site 6, an ancient tree has been broken off to about four feet above the ground and spilt in half. The remnant remaining in the earth is pock marked with with trails and caves of insects that reminds me of the cave houses carved out of volcanic tufa in Cappadocia in Turkey. In the lower canyon, still half-alive cottonwoods have had much of their bark stripped away, and underneath the xylem and heartwood has taken on a sinuous, smooth, yellow texture like human skin. At Pleasant Valley and at picnic sites 9, 7, and 2, dead cottonwood snags are bleached grey-white. Where large trunk stubs are near the road, erosion has exposed their subsurface tap roots, and this reveals a tangle of gnarls that remind of Eastern paintings of nature. An example is below the Red Bridge.

Traveling down-canyon, a familiar pattern appears in the River birches, Box elder and Mountain cottonwood trees that line the stream. Multiple, large, mature trunks sprout from a single root, and at the base, numerous suckers rise. For these trees, the mixture of angled mature trunks and smaller shoots gives the impression of a circular fan opening or a fountain of water rising. In this respect, trees are simply a larger, woody version of the brome grass bunches in Pleasant Valley, further up canyon. I realize that my impression of trees as organisms that are born, grow, have a middle age, and the die is mistaken. Angled older branches grow and fall away, and this gives the young shoots an opportunity to grow and replace them. But both originate from the same tap root, from the same genetic material. In this sense, most of the trees in the lower canyon that surround the stream possess a form of immortality. My misconception of the lives of these trees is the result of my biased exposure to shade trees in the city. Those trees mimic the cultured form of an English oak forest. There, trees are manicured and husbanded as individuals by their human farmers. Those trees do experience an individual birth, a middle age, and a death. But the English form of a forest is only one classical European choice, and here in the canyon, the stream trees pass their lives in a cycle and not along linear time.

In Thoreau’s “Journal” on February 22nd, 1856, he observes the first insects of spring crawling over snow.

On February 22nd, 1910, the City Council debated whether to lease a second gravel pit in lower City Creek (Deseret Evening News). On February 22nd, 1894, an attorney sought permission from the City to hunt a mountain lion in City Creek Canyon. Permission was granted and the hunter took a cougar (Salt Lake Herald).

February 21, 2017

February 21st

Filed under: Astronomy, Geology — canopus56 @ 10:20 am

Star Dust

8:30 a.m. It is another clear, sunny, warm day, and the morning sun climbs down the east facing canyon walls. Dust can be seen in the air of the canyon and now as an orange brown tinge on the last remnants of snow banks at the side of the road. A few dust molecules in the canyon have fallen on the road from outer space or as I jog, I have inhaled some of them into my lungs. In 2014, Gardner at the University of Illinois and colleagues, using a laser to measure the upper atmosphere, made an improved estimate of the number of tonnes of space dust that falls on the Earth each day: about 60 tonnes (Gardner). The dust consists of particles emitted by the Sun, contained in the interplanetary dust ring in the plane of our solar system, grains from the collisions of asteroids, the remnants of comet tails, and to a lesser extent, interstellar dust particles from other solar systems (Gardner; Westphal). Doing some rough, simple estimating, there are 907,185 grams in a ton and 510.1 trillion square meters on the surface of the Earth, including the oceans. Thus, there are 1.76 x 10^-8 grams of space dust falling on each square meter of the Earth everyday. There are 19.2 square miles in the canyon and the canyon first began to form 11 million years ago (Hintze). Thus, between its formation and the present, about a 1.76 square meter of star dust has fallen on the canyon; a cube whose one side is about the height of a man. That dust is spread on the canyon’s surface, is embedded in its rocks, or has washed away and or eroded out to the Great Salt Lake. Every day, I jog about 4 miles or 6,500 meters. During that jog, I estimate that the 6,500 square meters that I run over contain a total of approximately 0.0001 grams of star dust. In a sense, as Joni Mitchell reminded us, I am also star dust because the Earth and everything on it was formed from the dust left over by an Archean nova. That I am running each day through a few molecules of new space and interstellar star dust gives me a sense of a connection to wider universe outside of my daily life.

February 20, 2017

February 20th

Filed under: Bald-Faced Hornets, Blacked-Headed Chickadee, picnic site 4, Wasp — canopus56 @ 1:57 pm

Hornet Nest

Opened Hornet Nest

External Link to Image

Source: Author. The nest is rotated 180 degrees and in nature points down.

10:30 a.m. It is a very windy day, and a holiday. The wind blows leaves on and by the side of the road in two patterns. First, is a widening v-shaped spray. Second, the brown leaves dance together in a circle and are driven by a hidden dust devil. The canyon is again full of strollers, runners and bicyclists. The Black-billed magpies have come around the ridgeline from Ensign Peak (Feb. 15th), and taken up residence near picnic site 2 and down canyon from the Black-capped chickadees.

Near picnic site 4, I peel back the bark of a horizontal fallen snag. Underneath the bark are no insects, but there are long strands of a fungus sticking between the trunk and the bark. Hidden well up under the bark is a Paper wasp nest. The wasps carefully choose this place. Only a small opening in the bark leads down a tunnel to their hidden fan shaped nest. This is the natural version of their human adapted nests at the Red Bridge and in the natural gas pipeline valve station tubes (Dec. 10th). At those sites, the Paper wasp nests are inside metal fence hangers and bridge tubing. At picnic site 9, the hornet’s nest that I discovered on September 27th, long abandoned, has finally fallen from its tree. Inspecting the nest, it is apparent how the Bald-Faced hornets, who are a more social form of wasps, have engineered an evolutionary improvement in home building over their cousins, the Paper wasps. The Bald-Faced hornet nest also contains fanned shaped crèches that hang down from an attachment point. But in the hornet nest, they have constructed apartment style tiers. From the middle of the first, largest tier, a stack protrudes and on the bottom of that stalk, a second tier hangs. The third smallest tier hangs below. The diameter of the respective tiers contain 17, 12, and 9 cells, and this suggests that this compact eight inch high colony contained about 380 individuals. It is around this that the hornets build a thin multi-layer shell about two to three times the central colony. The shell contains air gaps that provide ventilation and natural cooling. The nest’s core colony is a marvel of insect engineering and the broken outer paper shell an artistic swirl of gray toned bands. That such beautiful complex construction can arise from simple, almost robotic insects is inspiring.

On my way down-canyon, I check the five hornet nests that I inventoried on December 10th. Winter weather has blown all from the trees. In a few months, will they will rebuild at the same locations?

In Thoreau’s “Journal” on February 20th, 1856, he finds otter tracks.

On February 20th, 1909, City Engineer Louis C. Kelsey reported on infrastructure accomplishments across several years of his tenure (Salt Lake Tribune, Salt Lake Herald). He recommended the replacement of the wooden flume below the City Creek Brick Tanks reservoir be replaced with a concrete flume and that water mains be extended into the business district.

February 19, 2017

February 19th

Filed under: Blacked-Headed Chickadee, Horsetail, Lichen, picnic site 4, picnic site 6 — canopus56 @ 6:19 pm

Blue-Green Lichen

4:00 p.m. It rains into the afternoon, but around 3:00 p.m. the Sun reappears. Horsetails have tan pads that divide each green segment, and usually, these go unnoticed. But the rain makes the green more vibrant, and where horsetails hang over the stream, the beige segments are highlighted. Drops of rainwater stick to the cylindrical segments and randomly fall into the stream below. In response to the continuing warmth, the Black-capped chickadees have moved further up canyon to mile 0.6. Now that the snow is gone, it leaves behind a flattened mat barely 1/16th inch thick of soaked leaves. In the autumn, these covered the ground to a depth of four inches. Scraping at the mat with a stick, one small insect is dislodged. All is primed for leaves’ decay back into soil, and the ground only waits the addition of spring’s heat. Testing the Box Elder catkins, the helicopter seeds easily come loose and are awaiting the strong winds of March. At picnic site 4, an unusual lichen stands out. Lichen is uniformly orange on trees in the lower canyon, as was this specimen. But the lichen on this tree has changed in the last week; it now has an orange green tint. Examining the lichen closely, under the orange lichen miniature green moss-like leaves are fruiting. Interspersed with these plants are three-quarter inch circles of a kaleidoscopic blue-green lichen. The centers are slate blue, the border is light blue, and a splash of new growth light blue-green tops the mass. At mile 0.2, I find another “mystery hole” next to the road (December 3rd). This hole is only four inches in diameter, and on exploring it with a stick, it is at least eighteen inches deep.

In Thoreau’s “Journal” on February 19th, 1852, he notes that the lengthening of the days is a sign of the coming of spring. At night, he sees a bright auroral display that covers the entire northern horizon. On February 19, 1853, he finds more insect cocoons.

On February 19th, 2006, a moose wandered out of City Creek Canyon and into the Avenues where wildlife officers tranquilized it for removal (Salt Lake Tribune). On February 13th, 1913, 49 head of cattle were found illegally grazing in City Creek Canyon and were impounded by the City (Salt Lake Herald). On February 19th, 1912, Superintendent of Waterworks Charles F. Barrett recommended tunneling in City Creek in order to develop new water supplies for the City and to reduce current water shortages (Salt Lake Telegram). On February 19th, 1903, City Councilperson Hewlett recommended building a reservoir in City Creek Canyon (Salt Lake Tribune). On February 19th, 1896, Charles Stewart, the manager of a mine in Hardscrabble Canyon just on the other side of the City Creek divide, argued for the development of a road down City Creek Canyon from Morgan County (Salt Lake Herald).

February 18, 2017

February 18th

Filed under: Colors, Light — canopus56 @ 6:56 pm

Orange Light

3:00 p.m. Last night, it rained continuously, and today is overcast. On February 6th, I noted a beautiful orange diffuse glow that flooded the canyon for about fifteen seconds near sunset. On the evening of February 16th, while I am driving around the valley floor near sunset, the orange glow reappears, and I see its cause. A low cloud bank hung over the valley with clear skies to the far west. The clouds were banded, that is they was long north-south running parallel bands generated by gravity waves. From each band, streamers of vapor hung in vertical curtains. The curtains were not falling rain; they were held in a temporary state between being cloud vapor and falling rain. The sun set under the cloud layer and streamed through the series of hanging curtains, and this generated the diffuse magical orange glow that lasted for about thirty seconds.

In Thoreau’s “Journal” on February 18th, 1854, he observes that leaves that have spent the winter under snow are brown on the topside but white on the underside.

On February 18th, 1910, the City public grounds committee considered a request to expand a gravel pit in City Creek Canyon by adding an asphalt plant (Deseret Evening News). On February 18th, 1894, City Waterworks Superintendent Daniel S. Griffin recommended the abandonment of 1.5 miles of wooden channel in City Creek between the High Line station and Capitol Hill and the replacement of the wooden channel with iron pipe (Salt Lake Herald). No water is supplied north of Ninth Avenue. City Creek Canyon supplies about 7.9 million gallons of water each day to the city.

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