Nevada and Arizona, USA, 20th October 2014.

After the helicopter flight, we briefly visited Hoover Dam.  This was built between 1931 and 1936 partly as an employment-generating project during Depression years.   It was at the time the world’s largest concrete dam and by 1939 it was the world’s largest electricity generating plant.   One hundred and fifty-four workers died during construction, not including the sixteen workers who died of heat exhaustion during a couple of days in 1931 when the temperature reached 49°C (120°F).

Bridge and Dam from helicopter.

This was at a lift at the dam.  A No Firearms sign is not something you expect to see in countries other than the USA.

There has been an extended drought for several years and you can see how far the water has dropped.  Lake Mead is now at 39% of capacity and there are many demands on it including aqueducts to California and Arizona and high dependence by Las Vegas including for drinking water.  It is at the lowest level it has been since the dam opened and the drought has continued for fourteen years.  There doesn’t appear to be any sense of crisis as yet.

Nevada and Arizona, USA, 20th October 2014.

Now we turn to the final posts for the South-West Canyonlands and New Orleans trip. I did say I was intending to finish off the North Atlantic images first, but I have changed my mind, partly to assist in earlier producing images for New Orleans bands.

We flew from Canberra to Las Vegas, a 26-hour journey including a six hours trapped in a crowded Los Angeles airport, and arrived on the evening of the 19th October.  More on Las Vegas Later.

Early in the morning of the next day, we drove to a nearby airport for a flight over the Grand Canyon.  Here are members of our party:  Jools, Craig, Barbara, Keith, Glenn (our photographer guide) and a pilot.  Missing are myself (behind the camera), Dean and Kim (UDesign Tour organisers).

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This is Lake Mead, formed by the Hoover Dam, more on which in a later post….

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During the next few weeks, our trip will entirely be undertaken on the Colorado Plateau.   This comprises the Southern half of Utah, the northern half of Arizona and smaller parts of Colorado and New Mexico.  This is a remarkable area for geologists because it is mainly bare rock and they can read the passages of the aeons in the layers of the rocks.

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The oldest rocks in the Colorado Plateau are Pre-Cambrian, up to 1,800 million years old (the Earth is about 4.5 billion years old).  Most, though have been laid down since the Cambrian (from 540 million years ago).  For most of that time (since the beginning of the Cambrian), the Colorado Plateau was close to sea level, with various parts of it just above or just below.

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Different rocks were laid down at different geological periods, including sandstone from sand dune deposits, mudstone from marine deposits in shallow seas and shale from river gravel.  The layers are not continuous because some times they were being built up and sometimes eroded away.   Periods built up can be hundreds of metres deep and periods eroded away can have disappeared completely (at least from view).

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At the end of the Cretaceous, about 70 million years ago, vast pressures in the Earth’s crust created the Colorado Plateau, raising it thousands of metres from sea level.  Only 5 or 6 million years ago, the Colorado river started to erode away from the top of the plateau to the bottom, creating the Grand Canyon.  The walls of the Grand Canyon show different deposits from Pre-Cambrian to modern times.

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We are just entering at the end of the Grand Canyon.  It is 450 kilometres long, up to 30 kilometres wide and 1.6 kilometres deep.

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We landed at the edge of the Grand Canyon, allowing the helicopters to refuel.  You can drive to this place or take a bus and it takes four hours from Las Vegas.  This is also the location of the Grand Canyon Skywalk, where you can walk out over the canyon on a platform with a transparent floor.  However, it is not cheap and you are not allowed to take your camera (instead, you are expected to purchase supplied images).  The word is not to bother.

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On the way back, we flew cross-country instead of along the Colorado River.  The views were very different but I still found the patterns fascinating.  I was also facing into the sun for the return journey and had to be more careful of angles to avoid reflections from the insides of the helicopter’s windows.  The best way to photograph from helicopters is without any windows, which I have done before, but this was not possible on this occasion.

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Three of the previous four images showed dwellings in a very arid landscape.   This one is perhaps more curious.  We see a road to nowhere and a dead car at the end of it.  Why is there a road there in the first place?  Did the car break down or was it driven there to be abandoned?  (Cue Talking Head background music:  “We’re on a road to nowhere…”).

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It appears I was very lucky to get a good seat and be able to get good images.  Others in our group had less satisfying experiences, including being seated in the middle of the helicopter where obtaining any image was difficult.

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You can click on any of the images for a larger view.  This is true of all images in this Blog.

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