[X] My Assistant

[ngunn]

Compare the predicted view in the latest 'looking ahead'

http://ciclops.org/view/5825/Rev_118

with the nothern hemisphere polar map:

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[ngunn]

With reference to the Ciclops view I wonder if we'll be able to see if the four great 'Siberian rivers' at 9 0'clock (7 o'clock on the second image above) continue all the way to the polar seas?

[titanicrivers]

With reference to the Ciclops view I wonder if we'll be able to see if the four great 'Siberian rivers' at 9 0'clock (7 o'clock on the second image above) continue all the way to the polar seas?

Very neat images!!! Those curvilinear forms seem to gather ‘tributaries’ and head north. However they have been imaged (in T 30) at lower resolution SAR and do not appear very river like. (see image sequence below). Perhaps they are older valleys partially filled in with mid latitude atmospheric deposits; maybe some crustal tectonics produced them rather than running methane torrents. The channel of T 30 seemed to end long before the large lake coastline. Agree additional ISS imaging will be interesting nevertheless.

[titanicrivers]

T 21 also crosses some of the 'Siberean channels' and that SAR doesn't seem to give one the impression of fluvial carved channels either.

[ngunn]

Very neat images

Yes, but unlike yourself, Mike and others I don't make them but merely link back to them when relevant.

I agree, it's far too early to say what the 'Siberian rivers' actually are. I only give them that nickname because of their general appearance, scale and geographical location. On the evidence so far I would say they have probably been either formed or modified by liquid flow in a northerly direction, though not necessarily very recently. It will be fascinating to see if the new images confirm or alter this impression. If there is evidence of flow it will also be interesting to compare with the present regional gradient. A global elevation map of Titan was published recently - the one on wich Xanadu surprisingly turned out to be a depression. I'll try to find and post that link if nobody else does first. It would make an interesting additional layer on your excellent composites.

Ah - here's the paper:
https://www.sciencemag.org/cgi/content/abstract/324/5929/921
https://www.sciencemag.org/cgi/content/full/324/5929/921

EDIT :I don't have access to the full paper and can't find the Fig 3 elevation map anywhere, except in this tiny version -

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[Juramike]

I don't think Titan has yet revealed the full diversity of river channels that are on it's surface. There could be a lot of really funky forms that we haven't seen yet.

Picture this: A large channel gets carved out, then becomes covered by insoluble, yet permeable, airfall deposits. A lower rainfall rate could allow subsurface flow the creeps aslong and keeps the channel deposits to remain wet (thus dark), but not be enough to clear out the channel.
(Terrestrial example: a small creek covered by snow. It still flows, it keeps the snow damp, but the channel is partially hidden.) Could this exist on Titan? Maybe.....

Or these could be cycloid cracks, or they could be curvy branching subparallel dark lines painted on just to torment us. (Just like the straight bright lines in Tseghi).

It'll be interesting to watch the story of the Siberian rivers develop as we get more data (ISS, VIMS, more RADAR, topoSAR, etc...)

[titanicrivers]

A global elevation map of Titan was published recently - the one on wich Xanadu surprisingly turned out to be a depression. I'll try to find and post that link if nobody else does first. It would make an interesting additional layer on your excellent composites.

An excellent suggestion! I was able to obtain the entire paper and although the paper tends to downplay correlation of surface features with the calculated regional elevations, (excepting the occurrence of lakes at the lower poles), the Titan ellipsoidal surface map does portray higher and lower regions that are of interest. For the "Siberian Rivers" region the surface suggest a higher to lower gradient concordant with the implied direction of flow of these channels as they roughly follow the course of the T30 SAR swath (see below).

[ngunn]

Looks like support for the possibility of flow at least. The elevation map projection though - doesn't it need 'unwrapping' into rectangular format before being overlaid on the ISS map?

[titanicrivers]

Looks like support for the possibility of flow at least. The elevation map projection though - doesn't it need 'unwrapping' into rectangular format before being overlaid on the ISS map?

Yes, the ellipsoidal map should have been expanded into a similar cylinidrical map as the ISS-SAR swaths map is; thanks for pointing that out.
In reviewing the paper again I found the straight altimetry data of the SAR swaths to be projected onto a cylindrical map format. This makes for neat composite and is a more accurate alignment of the data and is shown below. The elevation gradient support for northern flow of the 'Siberian Rivers' is still evident. Notable too is the Adiri 'high ground' and some higher elevation points in the area of possible VIMS mountains. (thats what I was trying to show with the Senkyo post!).

[ngunn]

Hey - that's brilliant, thanks!!

I see that the Adiri high is nicely placed to fit with catastrophic eastward flow at the Huygens landing site.

[titanicrivers]

I see that the Adiri high is nicely placed to fit with catastrophic eastward flow at the Huygens landing site.
[/quote]

Yes and take a look at the first part of T 39 swath below Adiri. This swath traces south poleward and the altimetry data (actually SAR monopulse radar mode data ) shows a several hundred meter drop. Looking closely at the swath one can spy what appears to be a rough hilly area then marked fluvial erosion and channels and finally a low spot- funky basin. Perhaps I'm reading too much into this but it seems to be there in the data and its kinda fun to do!
EDIT: yes I know that 'basin' at point b may be a plateau! given its radar bright appearance. However it kinda reminded me of that area in T 30 immediately to the east of Kraken that appears to blend with the lake and is also radar bright.

[titanicrivers]

Hey - that's brilliant, thanks!!

I see that the Adiri high is nicely placed to fit with catastrophic eastward flow at the Huygens landing site.

The elevation gain with the Western edge of Adiri and the net higher ground (possibly from the linear chains of hills) seems consistent however the eastern ends of the T8 swath shows greater elevation decrement in the northern most part of the swath. The Huygen's landing site is a bit south of that, where elevation change seems more modest and hill chains more prevalent. For the graphic below I used the SAR monopulse radar mode elevation data from Zebker et al https://www.sciencemag.org/cgi/content/abstract/324/5929/921 and mapped it to a moderately high (128 pixel/deg.) resolution T8 swath obtained from Perry's SAR radar swaths and swath map compilation. Realizing the elevation measurements may have some inherent error for such zoomed in sites, the color scheme nevertheless produces a pleasing end graphic of the HLS (Huygen Landing Site).

[ngunn]

That is nice, indeed, even though the resolution of the altimetry must be comparable with the size of the entire final image! Nevertheless it's not hard to imagine that if a large volume of rain fell suddenly on Adiri a significant portion could end up sliding off down the regional slope in the general direction of the landing site.

(Only a few days now, and we should be able to get back on topic. )

[ngunn]

Looks like Cassini has been lucky with the weather this time:

http://saturn.jpl.nasa.gov/multimedia/imag...3/N00142742.jpg

[volcanopele]

Are you telling me we actually saw clouds, lots of clouds, in an observation titled CLOUD001?!? Balderdash!

EDIT: actually, this was NPLCLD001, still same idea...