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.

4 comments:

Anonymous said...

Emil, som vanligt mycket intressant ackompanjerat med fantastiska bilder. Jag tycker du skulle passa som frilansfotograf och skribent i National Geographic.

Lena

Hans Christian Cars said...

Hi Emil,
Was that "lady" really that well-educated? Was she really so pleasant and how do you know, she was not herself one the more fundamental members of the conservative class of the US?

Emil Ems said...

Dear Lena, thank you kindly for your comment. Unfortunately, at my age, it is a bit too late to start a new professional career ;-)

And thanks also to you, Hans Christian! The Lady in question appeared well-educated and reasonable enough, that is, before we touched upon the topic of President Obama!

Yours sincerely
Emil

Harry Pottol said...

Emil,

Eugene and Carolyn Shoemaker, co-discoverers of at least nine comets, went to Germany looking for an impact crater. Specifically, they were looking for rocks containing tiny bits of the exploded meteorite from millions of years ago.

They arrived in town and stopped to look at a church. They were startled to find that the church was built of stone with these properties! They were able to trace the stone and expedite their search.

Harry