Thursday 19 December 2013

DISC WORLD

Looking South from Grand View Point Overlook on Island in the Sky
If you – like me – have kept a certain sense of boyish wonderment, you may have delved into Science Fiction books now and then and be familiar with the work of Pratchett. His is an elaborate vision of an alternative world, not a globe like ours, but flat and with a distinctive edge where it ends. If you were standing at that world's end, you would look down a vertical cliff of indefinite height, with mist and distant fog hiding the down yonder.

This vision came to mind when I was clinging to the edge you are seeing above, in company with the ant sized persons standing in the upper right of the picture. What were we seeing, when looking beyond and below this impressive red precipice? Precipice is the right word for it, since it is sloping down for almost half a kilometer, before ending in a flat basin of White Rim Sandstone (actually, the color is more brown-like) that stretches many kilometers to the South.

About halfway into that basin, a mighty river, the Colorado, has cut a meandering deep valley into the White Rim Sandstone, called The Loop. At the opposite side, you can barely glance, in the mist, a wall that must be about the same height as the one we are standing on top of. Further out, plateau upon plateau is filling the void, with the odd higher mountain or two towering over it all.

Colorado Meander ("The Loop") South of Island in the Sky
The edge we are standing on belongs to a small and narrow tableland, called Island in the Sky. This plateau is jutting out, like a peninsula, into a broad and wide basin shaped by the eroding confluence of two mighty rivers, the Green River and the Colorado. We are in the very core of an immense collection of tablelands, called the Colorado Plateau, one of the utmost wonders in the world. The Colorado Plateau is about twice the size of Sweden. From where we are standing, and looking South in the direction of the picture above, it reaches out for another 60 miles or so – and we are talking SWEDISH MILES here, not paltry Imperial ones.

How did this immense region of flatland upon flatland, situated at an average 2 kilometers above sea level, come to be? That expanse is something of an anomaly in the geologic scheme of things. It consists of a single, very (many kilometers) thick block of Earth crust that has remained remarkably stable over the eons (the past 600 million years), with very little disruption like faulting or folding of rock layers; this in stark contrast to all surrounding regions in America.

About 30 million years ago, this whole block, essentially flat, was lifted some 3 kilometers upward, by forces still uncertain. It was raised as a unified "table", albeit with a slight upward tilt towards the North. The main rivers already existed before that and could resume their eroding tasks with a vengeance at the increased altitude. The result we can nowadays admire as an immense region of flat tablelands at differing altitude, interspersed with canyons and wide basins; all caused by eroding streams, helped by their friends the wind, rain, snow, ice and sand.

Rim of Island in the Sky
We had reached the view point mentioned above on our way to Upheaval Dome (Bubble or Trouble?). On the way there, our guide made a brief stop at Island in the Sky's Visitor Center, to give us hikers a chance to get acquainted with the National Park. There we were told that a Ranger would give a presentation at eleven am at the Grand View Point Overlook. Now, Rangers are generally excellent presenters, with many acting out an impressive performance so, off we rushed, eager to partake in the experience.

And we were not disappointed. The view from up there was extraordinary, as already described above, and the Ranger was busy preparing his lecture.

Ranger and hikers at Grand View Point Overlookt, Island in the Sky
And what a performance he gave! The theme of the day was the Powell Geographic Expedition of 1869 . John Wesley Powell was a one armed Civil War veteran, with some experience of river rafting, as well as a solid education in natural sciences. He decided to be the first to raft the waterway of the Green and Colorado Rivers, from Wyoming to the confluence of Virgin River and Colorado in Southwestern Utah. In this way, he intended to pass through and chart a major part of the Colorado Plateau.

He had nine companions with him, five of which made it to the end. One of the others, an Englishman, had enough early on and went on to more mundane things. The three remaining, experienced trappers and hunters all, gave up towards the end of Grand Canyon, fearing that they would not survive the rapids they saw ahead of them. They hiked out of the canyon, never to be seen again, whereas Powell forced the remaining narrows successfully and arrived at his destination, the Virgin River, unharmed two days later.

Ranger acting out Powell
Hearing the Ranger speak about this remarkable venture made you almost believe that Powell himself was standing before us. The man's exploits speak for themselves, but the presentation touched upon many interesting details not usually mentioned in the summaries made about his expedition. For instance, Powell had the habit of climbing the canyon walls, one armed, in order to gauge their height. This was done by measuring the difference in air pressure between bottom and top, so he also had to balance a delicate barometer in his pocket during each climb!

For us weaklings, just looking DOWN one of those slopes causes you vertigo, not to speak of climbing them with one hand in your pocket! This is a man of dedication for you! He also preserved many views of his trip for posterity in remarkably well made pictures.

Looking down Cataract Canyon     Courtesy: Bancroft Library
This picture, for which he also had to take a CAMERA AND TRIPOD with him, when climbing the canyon wall – isn't it amazing? –, shows a view of Cataract Canyon, a canyon just South of Island in the Sky, and carved by the Colorado soon after having been joined by the Green River. The river looks rather peaceful from above, doesn't it? In fact, this is the steepest and wildest reach of the Colorado, containing 64 rapids. No wonder Powell wanted to document it before daring its descent. 

Enheartend by these tales, we rushed onwards to our exploit of Upheaval Dome (Bubble or Trouble?). Another outer worldly experience! But the day was far from over. Upon our return from this big "hole in the ground" we stopped at another view point on Island in the Sky, called Green River Overlook. I am mentioning this brief interlude since it provided me with a vista already documented from a slightly different angle in the previous post.

The Anderson Bottom Rincon of Green River, seen from Green River Overlook
We are again standing on the Island's rim, but this time on its Western side, and looking in a Westnorthwest direection. The basin we see at our feet is carved out by the Green River, which at that stage is as mighty as the Colorado. The dark configuration on the upper left is intriguing. The river used there to run through a loop canyon cut out be itself, just like The Loop of the Colorado, seen earlier. However, it does not run through the loop anymore, since it has found a much shorter way by eroding down a dividing canyon wall. We are here admiring the so called Anderson Bottom Rincon.

You may recall an earlier picture taken along the trail to Upheaval Dome (Bubble or Trouble?). It was taken much further North on this Western Rim of Island in the Sky, at a lower altitude, and heading the camera towards Northwest. Therefore it does not show the Anderson Rincon any longer, rather, a stretch of the river basin further North.

Time to leave Island in the Sky, you think? "Yes!", in a way. But on that same day's afternoon we had rushed on to a further hike – weren't we hardy? – that took place on a small side-peninsula, jutting out southward from the Island at its Northeastern end. It has a rather narrow start, being only 30 meters broad there, and has its end-viewpoint just on top of a very scenic loop of the Colorado. It is called Dead Horse Point.

Hiking the Eastern flank of Dead Horse Peninsula 
Our hike started at the Visttor Center (it is a State Park), which is located at the narrow neck of the small peninsula. From there we went South on its Eastern side, all the way down to the view point. It was getting later in the afternoon, so we had to hurry, but there was still time to take a nice panoramic picture of the gorge below us.

I invite you to double click on the picture below, so that you can get it at full size. In mid-afternoon, the "light is getting right" for landscape pictures and you can see far on this one. On the upper left you are looking at the La Sal mountains, which we could admire already in Arches National Park (A City Built on Salt), although most of the snow on top had melted away since. Speaking of Arches, you can just about locate it as the light brown piece of land on the upper left under the La Sal. Below it you can also discover the huge red wall (partly hidden by the tower located in mid-distance) we had to climb with the car to get up there from Moab.

Looking North from Basin Overlook
Further down, let me point out to you to the two lakes located in the upper basin. You may have guessed already that those cannot be natural, with their azure color and incongruous location. And your guess would be right. We are seeing here a huge mining compound, which is producing Potash (potassium carbonate). This is done by pumping water with high pressure into the mines, thereby leaching out the salts in question. The resulting brine is then kept in the two large reservoirs we are seeing and left to dry. After the water has evaporated, the potash can easily be collected. A primitive but effective manner of production, and probably not very poisonous either. After all, we are talking about some kind of baking powder here.

But it is getting late in the afternoon, so let's hurry on the the main Viewpoint, which permits us a look straight down on the Colorado, as it is carving its curvy route through the wide plain.

Colorado neck seen from Dead Horse Point
At this stage spectators use to put two questions: Why "Dead Horse Point"? And where does the road lead, that you can glance winding around on the plain rounding the river? As to the first, there is an intriguing story behind it. The small peninsula in the sky we are standing on, was used, in olden times, by cowboys to corral in wild horse, the "mustangs" they caught in this wild landscape. Since the peninsula had a small neck, only 30 meters wide, you could easily fence it off there and keep the mustangs enclosed. The saying is that the cowboys selected only the best horses for sale and left the rest to die; there is no water up here so they either had to die of thirst on the spot, or die trying to climb down to the big river.

The road you are seeing is really a dirt trail, the White Rim Trail of fame. It circles all around the Island in the Sky – including its sidekick, the Dead Horse Peninsula – and mainly follows the winding courses of the Green and the Colorado. It was originally built by the State as an access road for miners, looking for promising stakes, but is nowadays a cult track for bicyclists and four-wheel drivers. If you feel the urge to go down there and join them, why not have a look at a famous blog describing a cycle tour along the road, with pictures and all. The picture below is borrowed from that blog.

Cycling the White Rim Road       Source: Anthony Sloan
That gotten out of the way, we can concentrate on our return hike, this time along the Western Rim of Dead Horse Peninsula. Again we were confronted with marvelous views, but this time quite different. What we were admiring here was a comparatively narrow canyon separating this small peninsula from the main Island in the Sky. Furthermore, the sun was now approaching an angle sufficiently low to get me excited as photographer!

Shafer Canyon Overlook, Dead Horse Point
So let's polish off our overlook pictures with a cosy panorama, actually my favorite picture from this trip to Utah. This time, I got even myself into the view, but don't ask me how! Only two of our group are missing, the rest busy with admiring the scenario. I said above that there was a narrow canyon separating us from the greater Island in the Sky. Let me emphasize this by pointing out to you the great wall on the horizon. It is cut off rather abruptly towards the upper left of this picture. This is nought but the Western Rim of Island in the Sky! This is were I was standing, a bit to the right of the cut-off, when taking the title picture of this blog post at eleven am that very morning.

Rim Overlook, Dead Horse Point. Island in the Sky in the background
You may think that the canyon in between is not as small as that! This may be true, but size is relative. Compared to the basin carved out by the two mighty rivers, it stands indeed as a small, and narrow feature of Canyonlands. And rightly so, since it was not created by either great river. Its creation must rather be sought in small rivulets of water trickling down from the upper plateaus, and getting substantial only in periods of heavy raining. But it does not take much to create a canyon! Imagine a small rivulet that is cutting off half a millimeter of sandstone beneath itself once a year, after a heavy rain. This makes a cut half a meter deep in a thousand years, but HALF A KILOMETER DEEP in a million years. And a million years is to geology what a blink of the eye is to us!

But we are still humans and to us it is important to get a nice meal once the sun has set. Fortunately, there were only 20 minutes left to hike back to the Visitor Center, where our car was parked. In the mean-time the sun had already settled behind low clouds, and a beautiful mellow light was shining over the sagebrush and the pinyon pines we had to sidestep along the way.

Hikers on Dead Horse Neck
It must have rained or snowed rather heavily a week or so prior to our arrival – shaving off another half a millimeter from the canyon floors –, since the sagebrush was showing off its very best bloomings. But, to brush off this blog post that has concentrated on big stones most of the time, below is a portrait of the Pinyon Pine, since I suspect most of you readers have scant an idea of what it looks like at closer range.

Pinyon Pine on Dead Horse Neck


Wednesday 11 December 2013

BUBBLE OR TROUBLE?

Standing at the Abyss
What is the Group of Eight – well, five of its Members – looking at here or, rather, turning its back on? We are all standing close to a steep decline on the edge of an enormous hole in the ground, somewhat surprisingly called "Upheaval Dome". The hole, which more appropriately could be called "Superbowl", is vaguely circular, has a diameter of five kilometers and is close to half a kilometer deep. If you were to put your mind to it, you could easily fit in there the largest man-made amphitheater on Earth, the Collosseum. Did I say ONE Collosseum? In fact, more than 80 of them could find their place in this vast expanse. Playing with the notion of setting up an opera on its bottom, the whole population of Utah would be able to attend the performance, with room to spare.

Upheaval Dome is located in Canyonlands National Park, and is accessible through a road starting from Moab Valley opposite the entrance to Arches National Park. As in the latter, your car has to climb a steep ascent, but on the Southwestern wall bordering the huge Salt Valley of Moab (see A City Built on Salt) in order to arrive at this new section of the high plateaus. I will have more to tell about the plateau itself in the next blog, so let's concentrate for now on our visit to the Dome.

Hiking towards Upheaval Dome
After having climbed the plateau's steep promontory, another half an hour's drive brings you to the trailhead. From there, you have to climb a steep slope for 15 minutes or so – isn't that always the case in the hikes I am reporting here? –, but after that it is a relatively easy hike of a few kilometers to the Dome. The terrain reminds you a bit of the trail to Delicate Arch (God's Delicate Fingers), leading you along on huge slates of tilting sandstone; the main difference being that you are treading on Navajo Sandstone here, instead of on Entrada Stone.

Still, when you the least expect it, wide panoramas open up along the trail. Have a look at the picture above: deep down below lies, towards the West, a basin that is bordered on the far side by another plateau, quite like the one we are standing on. Looking more closely down at the lowlands (you have to click twice on the picture to enlarge it!), you can just about glance some brown declines, that have been burrowed by the Green River on its way to meet the Colorado, some kilometers farther South. In fact, this whole basin must be the result of erosion following that river's burrowing, with rain, wind and ice keeping on the good work once started by the river.

Standing on a giant footstep
Coming back to our hike, the access to the Dome equals descending an oversized staircase of three steps of sandstone, with width and height of step as adapted to a giant. Once you have climbed down the last step, you arrive at a narrow ledge and, just a few paces beyond, an immense void is opening up at your feet. First you have problems of grasping the immensity of it. You are looking at this circular bowl carved out of layers upon layers of sandstone and it is not looking much different to you than the odd stone quarry or two that you have visited over the years.

Only gradually it dawns on you that the ants crawling on the gravel down yonder are actually fellow hikers ambling around huge boulders! Your brain is catching up with your eyes and your mind is rejoicing at the experience. How to convey this sense of wonder to you readers in a picture? I was standing there in the middle of the day – not the best time for portraying landscapes – and the camera could, even with the widest angle of the zoom lens, only capture about 1/6 of the expanse. Well, a wonder of nature deserves some consideration. So I took 8 pictures and pieced them together in a humble panorama. Even so, I was able to catch only about half the diameter of this underground bowl for you to look at.

Panorama of Upheaval Dome – about half of its expanse!
How was this "Superbowl" created? Surprisingly enough, scientists are of two minds about it. Early on, they believed that it was the result of a huge Salt Dome having been formed eons ago by tectonic pressure (like the salt wallowing I mentioned in A City Built on Salt, which had caused the formations in Arches National Monument, as well as the Moab Salt Valley). What a sight it would have been to behold it, a dome of pure salt, glistening in the sun, and surrounded by sandstone slates – disrupted and shoved aside during the dome's formation – like worshippers of a Goddess of White. Of course, such a dome would not have been able to withstand the powers of erosion for long and only the void left after its dissolution would have remained.

This hypothesis, romantic as it is, has – to our regret – succumbed to a more prosaic explanation. Geologists now believe the crater to have been caused by a meteorite, a "boulder" with about 500 meters in diameter that had crashed onto the plateau about 60 million years ago. This conclusion originally arose through a comparison of this crater with similar ones known to have been caused by meteorite collision, on Earth as well as on the moon.

One feature in particular singles out such a crater – if it is large –, namely that its very bottom is not level. Rather, there is a central uplift: the stone layers at this bottom of the initial impact suddenly find themselves bereaved of the huge wedge of stone on top of them that has weighed them down before the impact, but has now suddenly evaporated. This causes them to rise. If you have difficulties understanding this process, just think at the time when you had broken a bone in your arm and had to keep it in plaster for a month or so. Immediately after the plaster is removed, the arm will rise of its own, relieved from a weight it had to support for so long.

Complex crater after meteorite impact   Source: Center for Lunar Science and Exploration
If you care to take a look at the panorama again, you are seeing some white stone layers, seemingly embedded in the opposite rim. But in fact, these are miniature mountain peaks, ragged like splintered teeth in a boxer's mouth, located smack in the middle of the crater and rising some 200 meters from its bottom. Sometimes you have to look at an object from very far away to grasp its intrinsic structure. So why not look at the crater from the space station; modern technics permit us to do so without effort. That view shows us clearly the inner void of the crater, with the small mountain, clad in white, rising from its bottom center.

You can also see the staircase formation – which our group was descending whilst following the trail to the crater – as three semi-eroded ejection layers stemming from the original impact. In fact, if you double click on the picture below, to get it larger, you will actually see the hiking path we used to access the crater rim. It looks like a thin white ribbon on the upper left.

Upheaval Dome seen from Space Station         Courtesy: NASA
Still, even with these persuasive views, a clearly settling evidence for this hypothesis was long in arriving. Proponents of the Salt Hypothesis could point out that no trace of meteorite material ever had been found in the crater. Their opponents could respond, with glee, that no single grain of salt had ever been seen lodging either on its rim or bottom. After decades of dispute, the issue was finally settled in 2007, when two German scientists, Elmar Buchner and Thomas Kenkmann, found a host of tiny quartz crystals at the bottom, that showed clear signs of having been subjected to high pressure of a meteorite impact. So there, one mystery less in the world! A pity, isn't it?

Of course, when our group was standing at the rim, admiring the view, we had scant inkling of this decades-long scientific discourse. We were off to a nice hiking trip, after all! Soon it was time to retrace our steps, since we had another, longer hike ahead of us that afternoon!

Retracing our steps on the Upheaval Dome Trail
But there is one more tale to tell, before we end this post, hi-jacked hitherto by scientific arguments. On the way back to our car I had for some time company with a nice American lady, of a certain age. As it happens all the time in the US, we soon were immersed in a nice chat that made us forget the labors of the hike.

From discussing the wonders we had just witnessed, the discussion rambled on to our great luck of getting access to that wonder despite all. Just a few days before our arrival from Sweden in Utah, President Obama had reopened the National Parks and Monuments, after a month's hiatus due to his budget conflict with Congress. After congratulating ourselves for the good timing of our visits, the lady, to my great surprise, went on by putting all the blame for this shut-down squarely on the President.

Somewhat astounded by this rash conclusion, I asked her whether the Congress did not have to share part of the blame, too. "No!", was her firm answer, the President was the origin, not only of the recently resolved budget conflict, but of all the problems that had pestered US politics ever since his assuming office.

The descent to the trailhead just beyond the horizon
This emotional answer got me thinking. If even a pleasant and well-educated lady could entertain such fiery sentiments, how must the more fundamental members of the conservative class in the US feel about their Leader? Is there a murky undercurrent poisoning the soul of the conservatives, leading to strong negative feelings towards their President, akin to those we could observe in Sweden's conservatives vis-à-vis Prime Minister Palme decades ago?

In Palme's case, these feelings of – let's face it – hatred had been caused by a sense of betrayal. Was Palme not born into nobility and had he not disavowed his birthright by pretending to be a radical socialist, like a simple agitator from the working classes?

In the US, similar feelings could be at play, but caused by another form of perceived betrayal. Was Obama not, due to his colored skin, predestined to be of the class of servants to, and entertainers of, their "betters"? How dare he be better educated, and more eloquent, than even the best among the upper classes? And, insult upon injury, how dare he become Master of his masters?

Better stop here, lest I get accused of being a busybody, ignorant in US issues at large or, more importantly, to curb the megalomaniac tendencies in my personality. It would take years of solid sociologic research, like the one having been carried out by Myrdal, to judge class sentiments in a society other than our own. My thoughts are just simple musings, based on a short conversation along a pleasant hike.