Friday, February 19, 2016

See the Wind?

Stopping for dinner at the Antelope Truck Stop, near Burns, Wyoming.

See the Wind?
(inspired by Christina Rossetti)

Who has seen the wind?
Neither I nor you:
But if tumbleweeds stop traffic,
The wind is passing through.

Who has seen the wind?
Neither you nor I:
But when a train flies overhead,
The wind is passing by.

For several days, my house has threatened to take off for Nebraska. We huddle inside, loathe to go out and be pelted by sand and flying garbage. So this is a good time to share the assorted information, stories and photos I’ve collected over the years.

If southeast Wyoming is going have severe weather, it’s only fitting that it be wind. Our high-altitude prairies and broad ridges let the prevailing westerlies strut their stuff, especially in winter. Average speeds of 30-35 mph are fairly common. But 50 mph with gusts to 70 is altogether something else, qualifying as a storm. So it was on Monday—making the front page of the Laramie Boomerang, ahead of the State Senate budget debate. Two days later, we were warned it would happen again, this time lasting 36 hours.
These winds break trees, knock down fences, and close highways even when there’s no snow. They howl and shake the house, scaring the dogs. They unsettle me too, especially when they wake me in the middle of the night! I decided to make the best of it and educate myself. For example: Why does the wind blow?

Wind is ”bulk movement of air”—specifically from areas of high pressure to low (source). And that’s exactly what happened. Air moving toward a pressure low in western South Dakota rushed across southeast Wyoming (quotes in caps are from NOAA Forecast Discussion; italics are mine).
This was going to be an exceptional pressure gradient:
I braced the broken fence post, wished the dogs good luck, and left to commiserate with friends over coffee.

But a true storm didn’t materialize. Average wind speed never got above 38 mph, with gusts to just 49—mere spring breezes!

• • •

Still, there was plenty of howling and wailing, as winds will do. Remember that great song about the wind called Maria (muh-RYE-uh)? It’s the song of a lonely cowboy out on the plains, longing for his sweetheart far away. Maria first appeared in the novel Storm by George Rippey Stewart (1941). As he explained, “The soft Spanish pronunciation is fine for some heroines, but our Maria here is too big for any man to embrace and much too boisterous. … So put the accent on the second syllable, and pronounce it ‘rye’.” (source)

Away out here they got a name
For rain and wind and fire
The rain is Tess, the fire's Joe
And they call the wind Maria 

Maria blows the stars around
And sends the clouds a-flyin'
Maria makes the mountains sound
Like folks up there was dyin’.

But Stewart, cowboys, myself and everyone else who has described the sound of the wind are wrong. Wind is silent. What we hear are things it disturbs, rubs against, sets in motion, breaks: leaves and limbs shaking against each other; wooden fences being abraded and broken; sand hitting the windshield; standing waves in power lines. The howling might be due to vortices that arise downstream from objects (source).

Yeah okay … maybe technically the wind is silent. But I’m not about to say that “the vortex downstream from my house was really howling.” It was the wind!

• • •

Of course wind is not all bad. Plants, gods and humans use it to their advantage.

Dandelions, cottonwoods, willows and many more plants cast their seeds to the wind. Tumbleweeds travel with the wind, dropping seeds as they roll along.
Sending the kids out into the world (source).
“Please release me!”—to broadcast more seeds.

Fūjin, the Japanese wind god, carries the winds in a large bag. When the world was created, he let them out to clear the mist.
Wind god Fūjin is considered a terrifying wizard-like demon (source). Maybe it’s Fūjin’s howling we hear when the wind blows.

Humans farm wind, including here in southern Wyoming. We would have even more wind farms if there were large urban areas nearby. Our high winds produce lots of energy, for energy is proportional to the square of wind velocity. And when wind passes a rotor oriented vertically to its path, energy becomes proportional to the third power of velocity! (source).

According to the State Climate Office, Wyoming ranks first in the nation in terms of windiness. We could supply approximately 66 million homes with energy annually, if only we could get it there (i.e. approximately 42,875 sq mi of available windy land, with potential yield of 747 billion kWh per year with wind energy potential (average power) of 85,200 MW).
Wind power generated in Wyoming by month (2011; source). Note high levels this time of year.

To me, wind farms look like sparse forests of perfectly-spaced giant weird trees—reminiscent of baobabs.
Source (of base photo).
Moving turbines are mesmerizing—it's easy to be distracted driving through a farm.
Wind farms are nothing new. Residents of the High Plains have been harvesting wind for years—even without Federal subsidies.
This old windmill still pulls up water.

• • •

There are various ways to measure wind. Wind direction refers to where it's coming from. Direction is most often measured with a pivoting weather vane. Wind speed is measured with anemometers, e.g. propellers or rotating cups. But in a pinch, a wind sock can show direction, and give a rough approximation of speed by the angle at which it’s hanging. Here’s the famous Wyoming windsock, of which we’re so proud:

Friday, February 12, 2016

Geological Mementos

Memento (n.): an object kept as a reminder of an event or person.

My knick-knacks are dominated by rocks. But they're not just rocks. For in addition to sand, silt, quartz, feldspar, anorthosite and serpentinite, they contain memories.

Some are mementos of events: magma almost but not quite reaching the surface; raging rivers carrying debris from disappearing mountains; a rift tearing the continent, fortunately stopping in time to keep the country whole. (I'm exaggerating—it ceased hundreds of millions of years before the colonies left England.) Others remind me of people: early explorers of the American West; pioneering geologists; 19th-century naturalists; today’s geo-bloggers.

Tired of unappealing weather and cabin fever, I decided to make portraits of these rocks so I could enjoy the memories they trigger. (Note re scale: Lady Liberty's portrait is an inch across, 2.5 cm.)

“Hillers trachyte is a pale gray paste with large white crystals of feldspar and crystals large and small of hornblende.” Grove Karl Gilbert.
In 1869, while traveling down the Colorado River, John Wesley Powell spotted an unnamed cluster of peaks in the distance, which he christened the Henry Mountains. He presumed they were volcanic. Volcanic mechanisms were a hot topic at the time, so he sent the great pioneering geologist, Grove Karl Gilbert, to investigate. Gilbert discovered the mountains were not volcanic. In fact, they didn’t match any type of uplift then known. He concluded the Henrys were created by shallow intrusions of magma. He would describe and name this new type of uplift, calling it a laccolith.

In 2012, I camped where Gilbert had camped, at the base of Mount Hillers. I hiked up the slope to look at sedimentary strata tilted nearly vertical by intruded magma. A piece of “Hillers trachyte” went home with me as a memento.
South side of Mount Hillers.
Large crystals mean magma cooled underground rather than on the surface, as would be the case for a volcano.

• • •

Igneous and metamorphic stones pose on a sandstone boulder.
Three years ago, while walking up a draw in the sandstone country of eastern Utah, I was surprised to find rounded polished stones made of igneous and metamorphic rock. What are they doing here?! I was even more astounded when I read that they came from the ancient Uncompahgre uplift, which hasn't been around for at least 80 million years. These stones are ghosts of mountains past.

Enchanted by their story, I returned last year and followed the Cutler Formation south almost to Arizona. There, far from the source, the Cutler is made of sand and silt instead of cobbles. On the way home, I stopped near Gateway, Colorado, where the Cutler includes cobble/boulder conglomerates, indicating the source had been close by. I was standing on the "slopes" of the ancient Uncompahgres! I took home several ghostly mementos.
Coarse conglomerate deposited on the slopes of the Uncompahgre uplift.

• • •

The deceptive Uinta sandstone.
A billion years ago, the supercontinent Rodinia, which included North America, was coming apart. A tear ran east from the vicinity of today’s Salt Lake City. It eventually failed, but streams continued to fill the rift valley with sediments to a depth of some four miles! By the 1870s, it had become a sandstone that fooled the great geologists—Hayden, King, Emmons and Powell. None had expected to find sandstone that old (Precambrian).

It fooled me too. The cores of our mountain ranges usually are made of granite and metamorphic rocks. I thought maybe the mileage in the guidebook was wrong.
This is the Precambrian core of the Uinta Mountains?!
Layers of sediments deposited in a rift that once threatened to split the continent.

• • •

Sparky contemplates his humble role in the universe.
On my drives from Laramie to the West Coast, I’ve stopped a half-dozen times at the Lunar Crater area in central Nevada. I like to camp in the wide open country there, free of crowds and regulations. Usually I hike, and take photos of the amazing landscapes. But one time I set out in search of mantle material in a lava field (the mantle is the molten layer beneath the Earth’s crust, miles below the surface).

Volcanic magma sometimes carries up pieces of the mantle. I was looking specifically for olivine—greenish and a bit translucent. I think I found some. (I used Geology Underfoot in Central Nevada as a guide).
Green olivine, with pale plagioclase and dark pyroxene behind.
The Black Rock lava flow.
• • •

Strolling down a river, atop a ridge.
My most recently-acquired geological memento is the lithified remains of a river. Camels, rhinos and ruminating hogs used to come here to drink, 19 million years ago. Now a trail follows the river bed—on top of a ridge! In other words the valley bottom now stands high, thanks to topographic inversion.
The “little gray potatoes” are calcified silt nodules.
Silt nodules and sand, with bits of quartz from the Rocky Mountains. Not until I took the macro shot did I notice the tiny lichen "cups" (upper left; click on image to view).

• • •

And finally ... a rock wall?
The summit?
This round green rock—serpentinized harzburgite—is the most popular of my geological mementos. Friends pick it up, surprised at its heft. More than one has noted “it looks like a brain!” It's a memento of two different events. One is the creation of the California Coast Ranges—a crazy geological story which no one fully understands (or even close?). Somewhere in the process, mantle rock was squeezed up to the surface, becoming serpentinized en route.
The Big Sur Coast, land of dreams and mystery. Photo by R. Koeppel.
The elements took their toll—the green rock was weathered and broken. A fragment traveled down an ephemeral river, almost reaching the Pacific Ocean. But I intercepted it. That’s the other memorable event.
I dug the boulder out of the sandy bed of the Santa Maria River, shortly before meeting a man pushing a bicycle. “Buenos días” he said, looking at the rock. “Piedra grande verde” I replied. He smiled and continued on.

• • •   • • •

Notes on Gear

Aside from camera and tripod, the setup I used for rock portraits was simple and cheap. The light box is home-made, following Amanda’s instructions. The sun shining though a window provided light. I put the box on a music stand, with the desk almost flat. It was easy to raise, lower and tilt … except for the heavy serpentinized harzburgite brain which collapsed the stand to its lowest position. I had to adjust the tripod instead.
The dogs found this rock portrait stuff quite boring.

Monday, February 8, 2016

Old Friends (tree-following)

My circle of close friends includes two trees. This may seem odd, but it’s impossible to follow a tree for a year without become friends! It was Lucy Corrander who started these relationships, when she invited anyone with an interest to choose and follow a tree, and report on it monthly. That was several years ago. We haven’t quit. Now the gatherings are kindly hosted by the Squirrelbasket (read the latest news here).

Last month I announced I would follow a juneberry in 2016, once I found one. So far, snowy weather has limited my search. An excursion to potential habitat in Vedauwoo Glen was unsuccessful, but still fun.
We had the picnic area all to ourselves!

So for this month, I’m reporting on my old friends.
Old friends Sparky and the cottonwood tree (preparing to estimate height).
The cottonwood I followed in 2014 grows on the bank of the Laramie River, just a short walk from my house. I see it almost daily. I never did decide if it’s one tree or several (multiple trunks) nor its exact identity. At least one of its parents must have been a narrowleaf cottonwood (Populus lanceolata), but maybe this is a hybrid, with genes of the Plains cottonwood (P. deltoides). The hybrid is common in this part of the Rocky Mountains—common enough in fact to have a name: lanceleaf cottonwood (P. X acuminata). Backcrossing has produced everything in between, most frequently narrowleaf X lanceleaf. In other words … it’s a taxonomic mess.

Even in the middle of winter, I make my daily trek through the cottonwood forest along the river … as I did this morning to see how the tree was doing. Walking through the snow and bare trees, I think about the trappers who spent the winter there in 1831-32. They grew fat on bison, elk, deer and pronghorn antelope, but their horses wouldn’t eat the inner bark of these cottonwoods and so starved. The men realized too late that they had camped in the wrong kind of cottonwoods—the bark of narrowleafs (and the hybrids) is bitter.
I switched to black-and-white; it was that kind of day.
Old and new friends (Emmie in foreground).
Lots of buds up high, waiting patiently. Only three more months ...
At the base of the trunks is a secluded spot where elves and fairies gather.
The shredded plastic bag that was caught on a high branch in 2014 is gone. But now someone has flagged this tree. What does it mean? A university student’s study?

• • •

Last year I stumbled upon a willow growing in a nook in the wall of a small limestone canyon, shaded by junipers. I was surprised to find it in that dry rocky canyon. Furthermore, it was blooming—on February 23, in Wyoming, at 7200 feet elevation! I had to follow this tree and learn more.
Male pussy willow in bloom; February 23, 2015.
The silvery catkins emerging from the dark buds revealed it to be an American pussy willow (Salix discolor), specifically a male. These willows are famous for blooming very early. When I returned from vacation in late May, it had leafed out. Then in July I discovered how it survives. After a hard rain, a waterfall was cascading down the wall behind the willow. The pool at the base stayed almost a month, long after the waterfall was gone. This site is not as dry as it looks!
Pool at base (July 2015), possibly a swimming hole for elves and fairies!
The willow isn't as convenient to visit as the cottonwood. I have to drive across town, and walk about a half mile. And now it’s cold, snowy and windy. Who wants to walk in 30 mph winds?! But the sun is shining! But it’s cold! But the willow might be blooming! … that decided it.
Looking up Willow Canyon .
Hoping to see wild flowers in February, I crossed the snowy prairie, turned towards Willow Canyon, and post-holed through snow up the draw to the willow. There I found …
… the willow with it's canopy swaying and twigs dancing against the sky. Even in the canyon bottom the wind was blowing. I looked close and found white hairs emerging from a few of the dark buds—the first flowers of the season, on February 6! They were wonderful to see, but impossible to photograph. I collected two twigs and took them home.
Willow flowers are hardly showy, but I love this “bouquet”—it’s so nice that the flowers are emerging, confirming that spring will arrive again.

When I collected the twigs, a bit of white hair was visible at the tips of two buds. Now 24 hours later, one of the buds is beginning to bloom vigorously (relatively speaking), and a third is opening.
When male pussy willow catkins (flower clusters) first emerge, they are silky and suggestive of cats’ feet.
Male pussy willow flowers (lower right) have several stamens, a nectary, and a bract with long silky hairs.
Britton and Brown 1913 (via USDA Plants Database).

Tree-following ... let's do it!