Want updates? Opt out any time

News
« Are you a poet or a mathematician? | Main | News of the week »
Monday
Oct102011

Where on (Google) Earth #315

After a long break from this awesome game, I got WoGE #314 by simple recognition. I've never been to Florida, but have scoured the whole region looking for interesting modern analogs. So I have the honour of turning in the next edition; the time is 1100 ADT, 1400 GMT, or 44-07-07 ∇ 14:19:14 Lunar Standard Time. In case you're on the moon.

Where on (Google) Earth is the best way to tour the virtual globe since the mighty View-Master. If you are new to the game, fear not, it is easy to play. The winner is the first person to examine the picture below, find the location (name, link, or lat-long), and give a brief explanation of its geological interest. Please post your answer in the comments. And thanks to the Schott Rule, which I am invoking, newbies have a slight edge: previous winners must wait one earth hour for each win before playing—with a maximum of 48 (yes, some people are quite good at this game).

So: where and what the Dickens is this?

PrintView Printer Friendly Version

EmailEmail Article to Friend

Reader Comments (22)

OMG It's my lunch from last week. I wondered where I'd left it...

October 10, 2011 | Unregistered CommenterReynardo (Gillian)

I know WHAT it is, but I don't know WHERE it is! These are pingos with meltwater around them - melting pingos, therefore. I.e. somewhere in the Arctic, but I don't have time to search!

October 10, 2011 | Unregistered CommenterElisabeth Kosters

Being a pedantic german engineer I would politely mention, that the clue has 49.4949% more data as the previous picture ;-D.
And concerning the geology, I totally agree with Gillian's (always amusing) comment. Looks like an australian food delicacy. Maybe kangaroo pancake?

October 15, 2011 | Unregistered CommenterFelix Bossert

@Felix: I see your pedantry, and I raise you some pedantry. I think it's only fair to count the area, so you have to deal with the square of the proportional change. But I am willing to concede that my math was, at best, rough. Going by the change in the scale bar's length, I assert that I am offering 119% more data with this clue. It's a smokin' deal!

October 15, 2011 | Registered CommenterMatt Hall

The truth is alway in the middle: what about (49.4949%+119%)/2 = 84.25% ?

October 15, 2011 | Unregistered CommenterFelix Bossert

@Felix: Well, the truth is sometimes in the middle.

If the sides increase two-fold, then the area increases 2² = 4-fold. If that sounds weird, it might help to draw a picture. If the sides increase by a factor of 1.48, as here, then the area increases by a factor of 1.48² = 2.19. Since we started with an area of 1 (normalizing to the original area), then the increase is 1.19 units, which is 119% of the original.

But it's all academic because none of this helps figure out where this kangaroo pancake is. If it is a kangaroo pancake.

October 16, 2011 | Registered CommenterMatt Hall

Hi Matt. I didn't mean all this to serious, you didn't either. I just wanted to make the comments somehow livelier. Of course you are right if you compare the square kilometers of the two pictures. I was refering to your expresion more DATA and calculated for the Data/Information-content: Old Picture: op= pixel_x * pixel_y * scale // New Picture: np=pixel_x * pixel_y * scale // increase of data or information = np/op. The scale is meant to be the reference value (or constant) from picture-pixel to real geological content. I was thinking about the problem: if you increase the scale of your picture, by not increasing the resolution of your picture, on one hand you increase the area on display, but on the other hand you are loosing information of fine details (as they are summarized in one pixel). So by increasing the scale and not increasing the resolution of the picture you get in total more and less information/data.

So if we go on like that we will have to start a math blog. Sorry for the confusion.

And if nobody is going to solve this crazy picture in the next days, I'm going to forget that at the moment I should be still digesting my last WOGE-win. I've covered most of the Himalaya highlands so far, and found similar looking areas but not the correct spot.

October 17, 2011 | Unregistered CommenterFelix Bossert

@Felix: Ha! OK, I get it now. It's an interesting thought. It got me thinking about data, information, and knowledge. See my update to the post (I can't put images in comments, AFAIK).

The two halves of the image—depicting a mystery city—contain the same amount of data (whether defined by pixels, bit-depth, or approximate land area), and the same amount of objective image 'information' (per your definition), but obviously have different amounts of useful information. But this latter type of subjective information depends on knowledge of major cities and their landforms.

Likewise,I guess the clue I posted will contain different amounts of useful information for different people :)

October 17, 2011 | Registered CommenterMatt Hall

As a non geologist, in our WOGE315 I see the following information:
* the shadows lead to more northern areas.
* surface/texture: looks sandy, like some sort of desert
* no vegetation visible
* there has to be water at times, as we do have erosional valleys.
* These valleys can't be too old, as the edges are quite sharp.
* no dunes visible, so the 'soil' is not movable, or we do have no wind.
* the side walls of the valleys have layers like sedimentary rocks
* the second layer is white, whenever I see white rocks I do have limestone in my mind, or gypsum
* and of course we have these little somethings, diameter up to 200m
* around the larger 'little somethings' are lots of small dry gullies.
* the question is: are our 'little somethings" hills ore holes?
* The shadows should give the answer. The problem is, most of these structures do have no shadow, but a dark ring.
* If the structures would be a depression (for example carst sink holes, we could have limstone underneath)
the gullies would lead water into the potential sink holes. In this case we should see a shadow on the southern rim
of the potential depressions. If the black rings would be a layer of dark rocks, this layer should be clearly visible
in the larger valleys. There is no layer, so I would say, the structures are no depression.
* So if they are no depressions, and we have the gullies, we are looking on little hills.
* The dark rings could be a layer of dark rock , which has been eroded away, as the layer underneath is more resistant
* In the middle of our little sometings is a light ring, and in the center something with a shadow.
* If we go on with the hill theory, the light ring could be a layer of rocks on top of the black layer
* The little something in the middle is the problem, as the barely visible shadow suggests a little depresion. If the barely
visible shadow of the center would be in the north, it would be clear, that the center thing is a piece of rock, sheltering
the white layer and so the black layer and the structures would be little mesas.
* So we have left the theory of Mrs Kosters (her impressive CV brings a lot of weight to her theory) the 'little sometings" being pingos.
* Pingos do look like our structures from above, but what are the black rings?
* As Mrs Kosters made her comment, when the second picture was not published, she didn't had the information of the larger valleys.

As the rims of these valleys are sharp, they have been cut into the rocks by occasional water flows. In northern permafrost
areas, one would think, the long time freezing environment would round the rims. The black rings and chips of material are going to lead me into warm arid areas next weekend (with lots of trips into the arctic permafrost, as I'm not too convinced by my theory).

Is there anybody else with a theory??

October 17, 2011 | Unregistered CommenterFelix Bossert

Felix, the second picture also sent me straight to warm & arid, but no luck so far. Great spot Matt!

October 18, 2011 | Unregistered CommenterKent

28.244 N, 11.364 W
Southwest of Tam-Tam in southern Morocco.
A plateau in flat-lying Lower Cretaceous(?) sedimentary rocks incised by headward eroding streams. The dark spots appear to be ephemeral lake basins.

October 21, 2011 | Unregistered CommenterRon Schott

Typo Correction: the city is Tan-Tan, not Tam-Tam.

October 21, 2011 | Unregistered CommenterRon Schott

@Ron: Spot on, good work! I'm so happy someone found it.

Now I have a confession to make: I know nothing at all about the geology here. I've had this spot in my 'Mysterious' folder in Google Earth for at least 4 years, and I posted it hoping someone might know about the area. According to the OneGeology portal, these are Cenozoic sediments. But then there are these pits. In some spots they seem to be organized along curvilinear trends, quite straight and almost north-south in the images above. A few, like this one have some sort of stratified or striated rock (I assume) exposed at the bottom; but the lineations are oriented differently in each pit. All very mysterious... Fieldtrip!

October 21, 2011 | Registered CommenterMatt Hall

Congratulations to Ron, congratulations to Matthew! And also thanks to Felix for the nice summary. A great spot. There are a lot of publications on the Tarfaya basin (oil shales!) like this one http://www.springerlink.com/content/x8xhwuqkhln7a1m8/ , but it seems like no one has ever had a closer look at those pingo-like things...

October 24, 2011 | Unregistered CommenterChristoph

Oh, maybe we see one of those structures on Figs 2 & 3 here? http://doc.rero.ch/lm.php?url=1000,43,4,20091117092812-JI/Adatte_T._-_Oceanic_events_and_biotic_effects_20091117.pdf

October 24, 2011 | Unregistered CommenterChristoph

WoGE #316 is ready when you are. No Schott Rule, so get cracking.

October 25, 2011 | Unregistered CommenterRon Schott

I have posted our area at the blog Marokko Expeditionen. Mr. and Mrs. Schulz are living in Marokko, are travelling the area and if I am right, they do know every single pot hole in the road. Mr. Schulz kindly provided some very helpful information concerning the area. Unfortunately the discussion is in german so I translate it:

My question:
"In an international geological game, a location in the desert near Tan-Tan has been searched for. The geological explanation of the many little circular structures could not be explained clearly, as there are not many geological informations availabe in the internet. Did you travel this area? Are these structures holes (Dolinen)?"

Answer of Mr. Schulz:
"Yes, I do know this area well. With the structures I can see, that the area is 35-50km east of the coast. The holes in the ground are no sink holes (Dolinens). They are formed by water and wind erosion. When it rains the holes are being filled by water. When the holes dry out, the winds do the rest."

Many thanks to Mr. Schulz for these informations!

November 13, 2011 | Unregistered CommenterFelix Bossert

the link to Marroko Expeditione: http://schulzmarokko.blogspot.com/2011/10/nordafrika-nur-marokko-liegt-im-plus.html?showComment=1319313064769#c6687907269398366447

November 13, 2011 | Unregistered CommenterFelix Bossert

@Felix: This is great! Thanks for sharing this detective work.

I have not heard of such a thing before — a sort of arid karsting, where wind exacerbates small depressions. There must be some geologic control, since some of the pits are clearly aligned, presumably exploiting a weak layer in the rock, or maybe a fault.

And I still think we need an expedition to really sort it all out :)

November 13, 2011 | Registered CommenterMatt Hall

Hi Matt

This comment comes a bit late, but I'm on a coffee break and browsing the blog by tags today (Geomorphology) for a change, and that's how I got here. On the two halves of the Paris Image, it would be interesting to run on them an F-K spectrum to see what it telss us on - and quantify the amount of information (I got this idea from Steve Lynch, who not only works in seismic visualization, but also in remote sensing).

August 7, 2012 | Unregistered CommenterMatteo

PostPost a New Comment

Enter your information below to add a new comment.
Author Email (optional):
Author URL (optional):
Post:
 
Some HTML allowed: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <code> <em> <i> <strike> <strong>