fredag 20. mars 2015

Where on Google Earth # 482

Felix' WoGE #481 looked impossible at first glance. It showed a karst area, most likely in China since that is where this specific type of karst surface is most common. Looking closer I saw that it was not quite as impossible as I first thought, and from then it didn't take very long to find the correct location.

This WoGE is similar: It is a dune. Yet there are enough distinguishing features to place it in a fairly limited area, and I have included one feature making the location unique.

As always, post a comment with latitude and longitude and write something about the (geologic/geographic/hydrographic) feature in the picture. If you win, you get to host the next one. If you do not have a blog of your own, many of the regulars are very willing to help by hosting your puzzle.

Previous WoGEs are collected by Felix on his blog and a KML file.

After a week has gone, and with Easter holidays coming up, I think it is time for a hint:

I followed a stream upriver to the source, and I think I may have found the source of the black coating on the dunes. It also explains why there is a mine in such an inhospitable area, the source area is even worse!

11 kommentarer:

  1. What a wonderful picture! I can't remember I've seen something similar.

    1. Indeed!
      That formation, in the right near-center ... looks metallic, don't it?
      I'm betting ... Namibia :)

    2. I won't 100% rule it out, but I doubt very much that there are dunes like this in Namibia. Yes, there is something metallic-looking here, and as a hint I can sau that the colour of the dunes change with the season.

  2. Luis, Namibia also was my first pick, but if I didn't overlook it, it's not Namibia

  3. Four days already? I didn't expect this one to last THAT long - after all, it's not some small little hidden obscure desert. Admittedly it is not in the area best known for dunes, but... :D

  4. And then it's two weeks old. Do you need another hint?

    Most of the interesting things happen around the edges. This is NOT in the middle of a desert.

  5. Hmmm. I'm puzzled.

    In the original image, there are what I would interpret as shadows to the south of the hills; with north up, that means we're looking at the southern hemisphere, or the extreme southern northern hemisphere. The colors change with season---do the dunes become snow-covered?

    With the second picture, we now have glaciers, with drainage to the south. Australia is clearly out, and Africa doesn't look so good either (also the comments above). There is dust on the glaciers all the way up to the crest, so there needs to be significant wind present---or a nearby volcano. This should also be a fairly distinctive feature.

    It isn't a small little obscure desert, so we are probably talking something larger, like the Atacama, Gobi, or Talikman deserts. There is a mine, so Antarctica is out, too, not that the dry valleys are particularly tedious to search.

    There are no fluvial features I can discern on the original image. The dark stuff (technical term) seems to be flowing northwest to southeast. I would put the prevailing winds from the west, too.

    So that's where I am. Wandering the globe in search of a weirdly metallic, mined, color-changing dune system downhill (southeast) from some dust-covered glaciers.

  6. The glacier drains south into a river which runs west and then turns northwest when it meets the desert.
    The black coating on the dunes confuse the interpretation of shadows. The white stuff is deposited in seasonal lakes, not snow on the tops of the dunes. :D

  7. 37.683 N, 84.437 E
    (37.236 N, 85.800 E for WOGE 482b)

    Here, we have a dune/playa system at the base of an alluvial fan at the southern (southeastern) portion of the Taklimakan Desert. This alluvial fan, draining from the Kunlun and Altun mountains, is the largest alluvial fan in the world (source).

  8. You found it!
    I found somewhere - and can't find it again - that these dunes have a fine coating of magnetite dust in the quiet seasons, which builds up slowlly through the year. When the wind blows this drops to the base of the lee side. I think that mine extracts Chromium-rich magnetite from the playa.
    These strange black dunes are found on both sides of the alluvial fan, and nowhere else. That makes it unique enough that I thought it should be fairly easy to find - and there is only the one mine in the area.

  9. WOGE 483 is available here: