[X] My Assistant

[Juramike]

I put together a sequence of craters of similar erosion state (Recent or Fresh)starting from the Equatorial Zones up to the higher latitudes. Presumed average wind direction based on presumed drifts is indicated.



The Equatorial zone craters in the Sand Sea basins, like Ksa and Sinlap, have clear rims, interiors and debris aprons. Dunes are at the margins.



Further north, the T23 Crater which sits in Fensal basin, has a clear rim and debris apron, although the surrounding terrain has slightly RADAR-brighter wispiness (drifts?) as downwind streaks.
The recently released image of the Dilmun Crater at the same latitude, but on a bright area, has the same RADAR-brighter wispiness as downwind streaks and symmetrically placed at the edges of the windshadow of the crater.

The Dilmun Crater also looks very similar to the circular feature seen in the T16 Swath. I'd be pretty confident calling the T16 circular feature an impact crater based on it's similarity to the Dilmun Crater. [The streak to the left of the T16 crater is the RADAR SAR seam, other RADAR-bright streaks are in the immediate area and are downwind. Wind coming from the upper left in the image] The interior rim is also similarly crenellated. The T16 Crater is very similar to the Dilmun crater, but slightly buried so that the margin of the debris apron is less distinct.

The T23, Dilmun, and T16 craters are all at about 30N. Above this latitude there are very few identified craters.



The next graphic shows a circular feature at 58N latitude. Extrapolating the trend from Equatorial regions to the higher latitudes, we would expect it to be buried - which it appears. Only the rim is clearly visible. Topograpy seems to show that the center has been almost completely infilled.

At least with this limited sample, the trend is for craters to have subtle RADAR bright windstreaks and to become progressively buried as one goes from the Equatorial zones to the higher latitudes.

-Mike

[Juramike]

I put together a sequence showing changes in pattern of tectonic ridges/graben going from the Equatorial Sand Seas to higher latitudes. These image are grouped to show the pattern change as one moves to higher latitudes.



In the Equatorial Sand Seas, the tectonic ridges stand proud, as seen in T8 across Adiri. Inland portions, such as W Quivira in the T25/T28 mosaic in the graphic, show the ridges, and also graben between the ridges. The ridges are RADAR bright, while the graben are RADAR dark (smooth muds). Red arrows indicate the ridge lines. The average wind vector based on dunes or drift patterns is also shown.



Moving away from the Sand Sea basins, the T25 Swath in Tseghi shows bright ridge patterns (the graben are better viewed by ISS and VIMS). In the bright terrain margin in NE Fensal, the T28 RADAR swath shows a series of tectonic ridges, a surrounding RADAR dark grey deposit mantle (presumably higher elevation), then a lighter grey wind deposit (evidenced by mid-latitude RADAR bright dunes) and finally a RADAR darker grey valley floor deposit. More details on the T28 image can be found here (The Mountains of Titan thread, post 6). The T28 Swath hints at patterns in higher latitudes.

-Mike